JP4400501B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to a vehicular travel control apparatus that executes control for assisting a driver using travel path information.

Conventionally, a traveling safety device for a vehicle that appropriately passes a curve existing ahead of the host vehicle is known (see, for example, Patent Document 1). This travel safety device sets an appropriate vehicle speed that can pass the curve appropriately based on the shape of the curve ahead, and alerts the occupant when the vehicle is not at the appropriate vehicle speed, and automatically sets the deceleration device. It is to be operated.
JP 2003-252188 A

  However, the above-described conventional technology performs assist control that sets the operating time of the reduction gear and the magnitude of braking based on the state of the deceleration operation by the driver after the alarm is activated. Since the set appropriate vehicle speed is constant, the execution of the assist control may not match the driver's feeling.

  Therefore, an object of the present invention is to provide a vehicle travel control device that can execute assist control in accordance with the driver's feeling.

In order to solve the above problems, according to one aspect of the present invention,
Acquisition means for acquiring travel path information in the traveling direction;
Setting means for setting a target vehicle speed based on the acquired travel route information;
An alarm control means for controlling an alarm operation for the driver based on an alarm level corresponding to a speed relationship between the actual vehicle speed and the set target vehicle speed;
Detection means for detecting the driving operation state of the driver;
And a correction means for the set correction target vehicle speed in the increasing direction when the driving operation the gear intention by said detecting means is not detected after the alarm operation,
There is provided a vehicular travel control apparatus characterized in that the number of executions of an alarm operation corresponding to each alarm level is determined .

  According to this aspect, when the driving operation indicating the intention to decelerate is not performed after the alarm operation, it is an indication of the driver's intention that the assist is unnecessary, so the increase in the set value of the target vehicle speed is corrected and the actual vehicle speed and the target vehicle speed are corrected. By changing the speed relationship, the driver's intention can be reflected in the control of the alarm action based on the speed relationship.

  In addition, it is preferable to include a deceleration control unit that decelerates the vehicle so as to reach the set target vehicle speed when a driving operation indicating a deceleration intention is detected after the warning operation by the detection unit. If a driving operation that expresses the intention to decelerate is performed after the alarm action, the assist control is in accordance with the driver's feeling, so the deceleration control is performed so that the set target vehicle speed is reached without correction. Even if it runs, the driver will not feel uncomfortable.

  In addition, it is preferable that the alarm control unit controls an alarm operation for the driver according to an approach situation to a point that is used as a reference when the setting unit sets the target vehicle speed. As a result, it is possible to perform an alarm operation according to the approach distance to the point or the deceleration required before approaching.

  According to the present invention, the assist control can be executed in accordance with the driver's feeling.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is an example of a block diagram showing a configuration of a vehicle travel control device of the present invention. The travel control device for a vehicle includes a travel path information acquisition unit 1, a target vehicle speed setting unit 2, an actual vehicle speed detection unit 3, a risk degree / necessary deceleration calculation unit 4, an alarm control unit 5, a driving operation state detection unit 6, a deceleration Control means 7 and target vehicle speed correction means 8 are provided. Each component means is realized by a CPU, a ROM, a RAM, an electronic circuit, a sensor, and the like.

  The travel route information acquisition means 1 is based on information received from a GPS satellite by a GPS (Global Positioning System) receiver and detailed map information in a map database, and the position information on the map of the vehicle and the traveling direction of the vehicle. Is obtained. This detailed map information includes travel route information related to general roads and toll roads on which vehicles travel, and information related to buildings such as shops and buildings. The driving path information includes, for example, corner radius, cant, curvature, clothoid length, length of constant curvature, road surface inclination, number of lanes, lane width, railroad crossing, intersection, junction, pedestrian crossing, guardrail, sidewalk, Numerical information and facility information such as bridges, tunnels, toll road toll gates and ETC (Electronic Toll Collection) lanes are included. It may include traffic jam information and weather information on the road.

  The target vehicle speed setting means 2 sets the target vehicle speed (recommended vehicle speed) Vr of the own vehicle based on the traveling road information in the traveling direction acquired by the traveling road information acquisition means 1. A target vehicle speed Vr of the own vehicle for passing through a corner having a certain radius of curvature is set based on a map value as shown in FIG. The target vehicle speed Vr is set higher as the curvature radius R is larger. A result obtained in advance by a vehicle running simulation regarding the relationship between the curvature radius R of the vehicle and the target vehicle speed Vr is reflected in the map.

  The actual vehicle speed detecting means 3 is a vehicle speed sensor or the like, and measures the actual vehicle speed Vs of the own vehicle.

  The degree-of-risk / necessary deceleration calculation means 4 includes the road information acquired by the road information acquisition means 1, the target vehicle speed Vr set by the target vehicle speed setting means 2, and the actual vehicle speed Vs detected by the actual vehicle speed detection means 3. The risk degree D and the required deceleration A are calculated based on the above. The risk degree D indicates the degree of risk when the own vehicle passes a corner in the traveling direction of the own vehicle in the current vehicle situation. The necessary deceleration A is a deceleration necessary for the host vehicle to decelerate to the target vehicle speed Vr.

The risk degree D depends on the target distance L from the current position of the host vehicle to the approach point (target) in the traveling direction corner (target), the speed difference Vd between the actual vehicle speed Vs and the target vehicle speed Vr (= Vs−Vr). Change. The risk degree D is calculated based on a predetermined map or calculation formula. The risk degree D is calculated to be higher as the speed difference Vd is larger, and is calculated to be higher as the target distance L is smaller (when the target distance L is a predetermined value L1 (> 0) or more, the risk degree D is 0). This is because the risk increases when the speed difference Vd is large or the target distance L is small. On the other hand, the required deceleration A is calculated based on the relational expression “A = (Vr ² −Vs ² ) / (2L)”. The risk degree / necessary deceleration calculation means 4 calculates the target distance based on the coordinate information of the current location of the host vehicle acquired by the travel route information acquisition unit 1 and the coordinate information of the approach point of the corner in the traveling direction of the host vehicle. L is calculated.

  The warning control means 5 controls the warning operation for the driver based on the speed difference Vd, the target distance L, and the risk degree D calculated by the risk degree / necessary deceleration calculation means 4. An alarm level LV, which is a threshold value for executing an alarm operation, is provided for the risk degree D. For example, the alarm level LV is divided into three stages. As the target distance L becomes smaller (closer to the target), the risk degree D becomes larger, and each time the alarm level LV is reached, the alarm control means 5 controls the alarm operation.

  The alarm operation is performed by, for example, an audio alarm, a visual alarm, or a vibration alarm. Encourage the driver to decelerate by saying "The speed is too high. Please slow down the car." In addition, by providing a reaction mechanism on the accelerator pedal or a vibration mechanism on the steering wheel or seat, the driver is advised that the reaction force by the reaction mechanism or the vibration by the vibration mechanism will be used as an alarming action to encourage deceleration. You can also let them know.

  The content of the alarm operation at each alarm level LV described above is different, and the alarm content becomes stronger for the driver as the alarm level LV increases. For example, the alarm control means 5 executes only an audio alarm at an alarm level 1, executes an audio alarm + visual alarm at an alarm level 2, and executes an audio alarm + visual alarm + vibration alarm at an alarm level 3. .

  The driving operation state detection means 6 detects the driving operation state of the driver. For example, there are an accelerator position sensor, an accelerator switch, a brake position sensor, and a brake switch that make it possible to detect a driving operation that represents the driver's intention to accelerate or decelerate. The accelerator position sensor and the brake position sensor are installed in the pedal section and detect the stroke (angle) of the pedal. Based on the detected value, it is possible to determine the depression state of the pedal, and it is possible to detect a driving operation representing the driver's intention to accelerate or decelerate. The accelerator switch is turned ON / OFF according to the vertical movement of the accelerator pedal. For example, it is turned on when the accelerator pedal is depressed, and turned off when the accelerator pedal is not depressed. The stop switch is turned ON / OFF according to the vertical movement of the brake pedal. For example, it is turned on when the brake pedal is depressed, and turned off when the brake pedal is not depressed.

  The deceleration control means 7 executes an intervention control in which the required deceleration A calculated by the risk degree / required deceleration calculation means 4 is generated by a brake mechanism or a transmission to decelerate to the target vehicle speed Vr.

  The target vehicle speed correcting means 8 corrects the target vehicle speed Vr set by the target vehicle speed setting means 2 based on the alarm level LV in the alarm control means 5 and the detection information of the driving operation state by the driving operation state detecting means 6. It is.

  The vehicle travel control device of the present invention can correct the target vehicle speed Vr according to the driver's intention. When the vehicle travel control device specifies a corner in the vehicle traveling direction as a target, as an initial state, a certain width from the physical limit value of the approach speed with respect to the corner in the vehicle traveling direction is set based on a map as shown in FIG. Therefore, the target vehicle speed Vr is set. The physical limit value is a vehicle speed limit value that is assumed to be unable to pass through the corner in the traveling direction of the vehicle at higher vehicle speeds. When approaching the corner and the risk degree D reaches the warning level LV = 1, the first-stage warning operation for the driver is executed. At this time, if the accelerator pedal stroke after the warning operation is not changed to “return side of the pedal”, it is determined that “the driver does not intend to decelerate”, and the target vehicle speed Vr is one step. It is corrected to be higher. Using the target vehicle speed Vr corrected by one step, an alarm action execution determination is similarly performed. Thereafter, similarly, the target vehicle speed Vr is corrected stepwise by the return of the accelerator pedal, and when the vehicle speed reaches a certain level, the assist control by this device is finished. Hereinafter, three correction modes (FIGS. 3, 4, and 5) of the target vehicle speed Vr will be described as specific examples.

  FIG. 3 is a correction example of the first example of the target vehicle speed Vr. 3A shows the relationship of the risk degree D with respect to the target distance L, and FIG. 3B shows the relationship of the parameter group regarding the speed with respect to the target distance L.

  When approaching a corner and the risk degree D reaches the warning level 1 (FIG. 3 (a)), the warning operation for the driver is executed, and if the accelerator pedal stroke does not change to the "pedal return side", the target vehicle speed Vr is corrected so as to increase by one level (FIG. 3B). When the target vehicle speed Vr increases, the difference from the actual vehicle speed Vs (that is, the speed difference Vd) decreases, and as a result, the risk degree D that has reached the alarm level 1 temporarily decreases (FIG. 3 (a)). )). Thereafter, similarly, using the target vehicle speed Vr corrected by one step, the execution determination of the alarm operation is performed based on the relationship between the risk degree D and the alarm level LV. In the case of FIG. 3, when the risk degree D increases as it approaches the target, the alarm operation corresponding to the alarm level 1 is executed four times, the alarm operation corresponding to the alarm level 2 is executed twice, and the alarm level 3 is reached. The corresponding alarm action will be executed once.

  FIG. 4 shows a correction example of the second example of the target vehicle speed Vr. The execution determination of the alarm operation in FIG. 4 is basically performed in the same manner as the execution determination of the alarm operation in FIG. 3 described above. In the case of FIG. 4, the number of executions of the alarm operation at each alarm level is defined as one, and the number of corrections for increasing the target vehicle speed Vr at each alarm level is also defined as one. As a result, the same alarm operation is not repeatedly executed.

  That is, when approaching the corner and the risk degree D reaches the alarm level 1 (FIG. 4 (a)), the alarm operation corresponding to the alarm level 1 is executed, and the accelerator pedal stroke is changed to “pedal return side”. If not, the target vehicle speed Vr is corrected so as to increase by one level (FIG. 4B). When the target vehicle speed Vr increases, the difference from the actual vehicle speed Vs (that is, the speed difference Vd) decreases, and as a result, the degree of risk D that has reached the alarm level 1 temporarily decreases (FIG. 4). (A)). Thereafter, the execution determination of the alarm action is performed using the target vehicle speed Vr corrected by one step. However, even if the risk level D reaches the alarm level 1 again when approaching the corner (FIG. 4 (a)), the alarm level is increased. Since the alarm operation corresponding to 1 has already been executed once, the alarm operation is not executed. After that, when approaching the corner further and the risk degree D reaches the alarm level 2 (FIG. 4 (a)), an alarm operation corresponding to the alarm level 2 is executed, and the accelerator pedal stroke is changed to "pedal return side". If not, the target vehicle speed Vr is corrected to be further increased by one step (FIG. 4B). Thereafter, similarly, based on the relationship between the risk degree D and the alarm level LV, execution determination of the alarm operation is performed. In the case of FIG. 4, when the risk degree D increases as approaching the target, the alarm operation corresponding to each alarm level is executed only once, so that the redundancy and complexity of the alarm operation is also eliminated.

  FIG. 5 shows a third aspect of correction of the target vehicle speed Vr. The execution determination of the alarm operation in FIG. 5 is basically performed in the same manner as the execution determination of the alarm operation in FIGS. In the case of FIG. 5, the target vehicle speed Vr is determined separately for the alarm target vehicle speed Vra and the brake target vehicle speed Vrb, and only the brake target vehicle speed Vrb is corrected to be increased, and the alarm target vehicle speed Vra is not corrected to be increased. (FIG. 5B). Further, the risk degree D is also divided for alarm and brake. Thereby, it becomes possible to correct | amend alarm control and deceleration control independently.

  In other words, when approaching the corner and the risk degree D reaches the alarm level 1 (FIG. 5A), an alarm operation corresponding to the alarm level 1 is executed, and the accelerator pedal stroke changes to “pedal return side”. If not, the brake target vehicle speed Vrb is corrected so as to increase by one step, but the alarm target vehicle speed Vra is not corrected (FIG. 5B). If the target vehicle speed Vrb for braking increases, the difference from the actual vehicle speed Vs (that is, the speed difference Vd) decreases, and as a result, the degree of risk for braking that reaches the alarm level 1 temporarily decreases (FIG. 5 (a)). On the other hand, the warning target vehicle speed Vra does not change, so that the warning risk level increases as it approaches the corner (FIG. 5A). Thereafter, similarly to the above-described method of the correction mode of FIG. 3 or FIG. 4, “determination of execution of alarm operation based on the relationship between the risk level for braking and the alarm level” and “the relationship between the alarm risk level and the alarm level Based on the alarm action execution determination based on, it is performed independently.

As shown in the drawings of the above three correction modes, the “driver target value” that is the target vehicle speed assumed by the driver approaches the target vehicle speed Vr set by the vehicle travel control device of the present invention. And assist control such as deceleration control can be executed in accordance with the driver's feeling. In particular, in the example of the correction mode in FIG. 5, only the brake target vehicle speed Vrb is corrected to increase, so that the assist amount by deceleration control (that is, the required deceleration A (= (Vrb ² −Vs ² ) / ( 2L))) only adapts to the driver's feeling. On the other hand, since the target vehicle speed Vra for warning is not corrected, the warning operation by the warning control is not adapted to the driver's feeling, and the timing of the warning operation is earlier than the intervention timing of the deceleration control. It will be.

  The operation example of the vehicle travel control device of the present invention described above can be expressed by the flowchart of FIG.

  When the vehicle travel control device specifies a corner in the traveling direction of the host vehicle as a target, the position information on the map of the host vehicle acquired by the traveling path information acquisition unit 1 and the traveling path information in the traveling direction of the host vehicle (step 2). And the target vehicle speed setting means 2 sets the target vehicle speed Vr of the host vehicle (step 4). The risk degree / necessary deceleration calculation means 4 calculates the risk degree D and the necessary deceleration A based on the target vehicle speed Vr, the actual vehicle speed Vs detected by the actual vehicle speed detection means 3, and the target distance L. (Step 6). The alarm control means 5 first determines whether or not the risk degree D exceeds the alarm level 1 (step 8). If alarm level 1 is not exceeded, return to the beginning of the flow. When the alarm level 1 is exceeded, the alarm control means 5 determines whether or not the alarm operation corresponding to the alarm level 1 is not executed (step 10). That is, this is a step showing the correction mode of FIG. If an alarm operation corresponding to alarm level 1 has already been executed, the alarm level used for determination of alarm execution is raised to 2 (step 12), and the process returns to the beginning of the flow. If not executed, an alarm operation corresponding to the alarm level 1 is executed (step 14). The target vehicle speed correcting means 8 determines whether or not the driver has released the accelerator pedal within a predetermined time (for example, within 0.5 seconds) after execution of the alarm operation by the alarm control means 5 (step 16). It may be determined whether or not the driver has depressed the brake pedal. When it is detected that the accelerator pedal is loosened, the target vehicle speed correction means 8 instructs the deceleration control means 7 to execute the deceleration control. The deceleration control means 7 executes deceleration control until the speed difference Vd between the actual vehicle speed Vs and the target vehicle speed Vr falls within a predetermined value (steps 18 and 20), and when it falls within the predetermined value, terminates the deceleration control, The assist control by the travel control device ends (step 22). On the other hand, if the accelerator pedal is not loosened even after executing the alarm operation, it is considered that the driver considers that the assist control is unnecessary at this stage. Here, the target vehicle speed correcting means 8 confirms whether or not the alarm level has reached the final stage (according to the specific examples of FIGS. 3, 4 and 5 described above, the alarm level 3 has reached the final stage) (step 24). ). If the alarm level is 1 or 2 and the final stage has not been reached, the target vehicle speed correction means 8 corrects the target vehicle speed Vr set by the target vehicle speed setting means 2 by one level (step 26). If the warning level has reached the final level 3, the assist control by the vehicle travel control device is terminated according to the driver's intention (step 28).

  When the alarm operation timing and the necessary deceleration A are corrected independently as in the correction mode of FIG. 5 described above, the target vehicle speed Vr is set separately to the alarm target vehicle speed Vra and the brake target vehicle speed Vrb in step 26. Will do.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  In the above-described embodiment, the corner in the traveling direction of the own vehicle has been described as a target, but the present invention can be similarly applied even when the target is a preceding vehicle. When targeting the preceding vehicle, the vehicle speed at which the relative speed between the preceding vehicle and the host vehicle is zero, or the vehicle speed at which the inter-vehicle time or relative distance between the preceding vehicle and the host vehicle is a predetermined value is set as the target vehicle speed. What can be considered as Vr. The target distance L at this time is a relative distance between the preceding vehicle and the own vehicle. This may be done by calculating the risk degree D as described above.

  When there is a corner and a preceding vehicle in the traveling direction of the vehicle, the risk degree D in each case is calculated, and the larger risk degree D may be treated as a target.

  The relative velocity and the relative distance can be measured using a millimeter wave radar, a laser radar, an ultrasonic radar, a stereo camera, or the like. The relative distance can be easily calculated from the relationship between the wave transmission / reception timing and the wave speed transmitted / received by the radar. The relative speed (the speed of the vehicle with respect to the preceding vehicle) is obtained from the time change of the calculated relative distance. In the case of a stereo camera, the relative distance is calculated by obtaining the parallax between images captured by image sensors (CCD: Charge Coupled Device) arranged on the left and right. When the image by one image sensor and the image by the other image sensor are superimposed, the preceding vehicle is shifted in the horizontal direction. Then, the most overlapping position is obtained while shifting one image pixel by pixel. The number of pixels shifted at this time is n. When the focal length of the lens is f, the distance between the optical axes is m, and the pixel pitch is d, the relative distance X from the own vehicle to the preceding vehicle is a relational expression X = (f · m) / (n · d). Is established. Note that (n · d) is called parallax. From the relative distance X calculated based on this relational expression, the relative speed can be calculated in the same manner as described above.

  Moreover, you may use the vehicle detection apparatus installed for every specific point of a travel path as a means to acquire positional information, such as a corner and a preceding vehicle. The vehicle detection device includes a vehicle detection sensor that detects a vehicle that approaches itself within a predetermined distance using infrared rays and the like, and a transmission device that transmits the vehicle detection result to surrounding vehicles. When the vehicle acquires information from the vehicle detection device, the positional relationship among the corner, the preceding vehicle, and the vehicle can be grasped.

  Further, in the above-described embodiment, the corner is the target, but the vehicle control apparatus of the present invention can be similarly applied to a railroad crossing, an intersection, a branch point, and an ETC lane. Assist control adapted to the driver's feeling can be performed toward these targets.

  Further, the target speed Vr may be corrected according to the surrounding environment of the target. When the travel path is a bridge or tunnel, the target speed Vr may be set lower than the initial value because it is harder to travel than a normal travel path. Further, for example, if the ambient temperature of the traveling road is lower than a predetermined temperature, the target speed Vr may be set lower than the initial value because there is a risk of road surface freezing.

It is an example of the block diagram which shows the structure of the traveling control apparatus for vehicles of this invention. It is a map which shows the relationship between the curvature radius R and the target vehicle speed Vr. It is a figure which shows the correction | amendment aspect of the 1st example of the target vehicle speed Vr. It is a figure which shows the correction | amendment aspect of the 2nd example of the target vehicle speed Vr. It is a figure which shows the correction | amendment aspect of the 3rd example of the target vehicle speed Vr. It is an example of the flowchart which shows operation | movement of the traveling control apparatus for vehicles of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traveling path information acquisition means 2 Target vehicle speed setting means 3 Actual vehicle speed detection means 4 Risk degree / necessary deceleration calculation means 5 Alarm control means 6 Driving operation state detection means 7 Deceleration control means 8 Target vehicle speed correction means

Claims (11)

Acquisition means for acquiring travel path information in the traveling direction;
Setting means for setting a target vehicle speed based on the acquired travel route information;
An alarm control means for controlling an alarm operation for the driver based on an alarm level corresponding to a speed relationship between the actual vehicle speed and the set target vehicle speed;
Detection means for detecting the driving operation state of the driver;
And a correction means for the set correction target vehicle speed in the increasing direction when the driving operation the gear intention by said detecting means is not detected after the alarm operation,
A vehicular travel control device , wherein the number of times of alarm operation corresponding to each alarm level is determined .   The vehicle travel control device according to claim 1, wherein the correction is performed stepwise each time a driving operation indicating a deceleration intention is not detected after the warning operation by the detection unit. The vehicle travel control device according to claim 1, wherein the number of times of execution of an alarm operation corresponding to each alarm level at which a calculated value calculated based on the speed relationship is reached is defined. It is determined whether or not an alarm action corresponding to an alarm level at which the calculated value calculated based on the speed relationship has been reached,
  The vehicular travel control device according to any one of claims 1 to 3, wherein when already executed, an alarm level used for determination of execution of the alarm operation is increased. The speed relationship is a speed difference,
  5. The vehicle travel control device according to claim 3, wherein the calculated value is calculated so as to increase as a speed difference obtained by subtracting the set target vehicle speed from an actual vehicle speed increases. 6. The vehicular travel control apparatus according to claim 5, wherein the calculated value is calculated based on the speed difference and a target distance to an approach point, and is calculated to be larger as the target distance is smaller. The target vehicle speed is set separately for the alarm target vehicle speed and the brake target vehicle speed,
  The alarm operation is executed based on an alarm level corresponding to a speed difference between an actual vehicle speed and the set alarm target vehicle speed,
  Deceleration control is executed based on an alarm level corresponding to the speed difference between the actual vehicle speed and the set target vehicle speed for braking,
  The vehicle travel control device according to claim 1 or 2, wherein the correction of the set alarm target vehicle speed and the correction of the set brake target vehicle speed are performed independently.   The warning operation is executed based on a warning level corresponding to a calculated value for warning calculated based on a speed difference between an actual vehicle speed and the set target vehicle speed for warning and a target distance to an approach point,
  The deceleration control is executed based on an alarm level corresponding to a calculated value for brake calculated based on a speed difference between an actual vehicle speed and the set target vehicle speed for braking and a target distance to an approach point. Item 8. The vehicle travel control device according to Item 7.   The set brake target vehicle speed is corrected without correcting the set alarm target vehicle speed when a driving operation indicating a deceleration intention is not detected after the alarm operation by the detecting means. The vehicle travel control device according to 7 or 8.   The vehicle travel control device according to claim 1, further comprising a deceleration control unit that decelerates the vehicle so as to reach the set target vehicle speed when a driving operation indicating deceleration intention is detected by the detection unit after the warning operation. 11. The vehicle according to claim 1 or 10, wherein the alarm control means controls an alarm operation for a driver based on an alarm level according to an approach distance to a point that is used as a reference when the setting means sets a target vehicle speed. Travel control device.

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