JP2013067365A - Preceding vehicle follow travel device and driving support system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a preceding vehicle follow travel device to control more the deterioration of fuel consumption.SOLUTION: It is determined whether a speed of a forward vehicle of a preceding vehicle is smaller than the speed of the preceding vehicle by a prescribed value or more based on the speed of the preceding vehicle and speed information of the forward vehicle of the preceding vehicle located forward of the preceding vehicle in the traveling direction on the same road of the preceding vehicle obtained by vehicle-to-vehicle communications. When determination is affirmative, and the speed of the own vehicle is equal to or less than the speed of the preceding vehicle, acceleration is controlled by interrupting the preceding vehicle following control and maintaining the speed of the own vehicle.

Description

  The present invention relates to a preceding vehicle following traveling device and a driving support system including the preceding vehicle following traveling device, and more particularly, to a fuel saving technique in preceding vehicle following traveling.

  2. Description of the Related Art Conventionally, a preceding vehicle following traveling device that can automatically follow a preceding vehicle and travel is known. As a preceding vehicle follow-up travel device, there is known a device that controls a vehicle speed according to an inter-vehicle distance from a preceding vehicle or a relative speed with a vehicle speed set by a driver as an upper limit.

  For example, Patent Document 1 discloses a technique for performing preceding vehicle follow-up using absolute position information and acceleration / deceleration adjustment information of a preceding vehicle obtained by inter-vehicle communication. In the technique disclosed in Patent Document 1, the inter-vehicle distance from the preceding vehicle is obtained from the absolute position information of the own vehicle and the absolute position information of the preceding vehicle obtained by inter-vehicle communication. Then, a deviation between the inter-vehicle distance from the preceding vehicle and the target inter-vehicle distance is detected, and the own vehicle is subjected to acceleration / deceleration control based on the deviation and acceleration / deceleration adjustment information of the preceding vehicle obtained by inter-vehicle communication.

Further, for example, Patent Document 2 discloses a technique of performing preceding vehicle follow-up travel using a corrected approaching / separating state evaluation index KdB_c in addition to the inter-vehicle distance and relative speed with the preceding vehicle detected using a radar. The corrected approach / separation state evaluation index KdB_c is an index obtained by correcting the approach / separation state evaluation index KdB in consideration of the speed of the preceding vehicle. Further, the approaching / separating state evaluation index KdB is an index representing the degree of change per unit time of the area of the assumed image assuming an image seen by the driver's eyes of the front object. The approaching / separating state evaluation index KdB and the corrected approaching / separating state evaluation index KdB_c are expressed by, for example, the following formulas 1 and 2, respectively. In Equations 1 and 2, D is the distance between the host vehicle and the preceding vehicle, Vr is the relative speed of the preceding vehicle with respect to the host vehicle, a is a multiplier, and Vp is the preceding vehicle speed.

  As shown in Equation 1, the corrected approaching / separating state evaluation index KdB_c increases as the absolute value of the relative speed Vr approaching the preceding vehicle increases. Moreover, it becomes small, so that the preceding vehicle speed Vp is high. Moreover, it becomes larger as the inter-vehicle distance becomes shorter. Further, since the inter-vehicle distance D is a cube term, the increasing gradient of the corrected approaching / separating state evaluation index KdB_c with respect to the change in which the inter-vehicle distance D becomes shorter becomes steeper as the inter-vehicle distance D becomes shorter. If the preceding vehicle follow-up running is performed using the corrected approach / separation state evaluation index as in Patent Document 2, the follow-up running with less discomfort for the driver is possible.

Japanese Patent No. 3480484 JP 2008-280017 A

  However, in the techniques disclosed in Patent Document 1 and Patent Document 2, the own vehicle performs acceleration / deceleration following the acceleration / deceleration of the preceding vehicle, which may cause unnecessary fuel acceleration / deceleration and cause deterioration in fuel consumption. Had problems. Details are as follows.

  A vehicle located ahead of the preceding vehicle on the same road as the preceding vehicle to which the vehicle is following (hereinafter, the preceding vehicle ahead) travels at a low speed due to traffic jams, or stops due to a breakdown or accident. is there. In such a case, when the preceding vehicle accelerates regardless of the situation of the preceding vehicle ahead or maintains high speed without decelerating, the preceding vehicle suddenly decelerates when it approaches the preceding vehicle ahead. Will do. In addition, the host vehicle that is following the preceding vehicle also follows the acceleration / deceleration of the preceding vehicle, so that unnecessary acceleration and sudden deceleration are performed. Therefore, there is a possibility that the fuel consumption is deteriorated by performing unnecessary acceleration / deceleration.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to perform a preceding vehicle following traveling device and an operation that can further suppress deterioration of fuel consumption in the preceding vehicle following traveling. To provide a support system.

  The preceding vehicle follow-up traveling device according to claim 1 is mounted on a vehicle, acquires information via a wireless communication device that receives information by inter-vehicle communication, and causes the vehicle to follow the preceding vehicle. Follow-up control is performed. Further, from the current position of the preceding vehicle determined by the preceding vehicle position determining means, the current position information of other vehicles other than the preceding vehicle acquired by the other vehicle information acquiring means, and the map data acquired by the map data acquiring means, the other vehicle Is a preceding vehicle forward vehicle determining means for determining whether the preceding vehicle is ahead of the preceding vehicle on the same road as the preceding vehicle, and the preceding vehicle forward vehicle determining means If it is determined, the speed of the preceding vehicle ahead is determined based on the speed of the preceding vehicle determined by the preceding vehicle speed determining means and the speed information of the preceding preceding vehicle acquired by the other vehicle information acquiring means. Speed determining means for determining whether or not the speed is less than a predetermined value. If the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is equal to or lower than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, the preceding vehicle follow-up Control is interrupted and acceleration is suppressed by maintaining the speed of the vehicle.

  When the speed of the preceding vehicle ahead is smaller than the speed of the preceding vehicle by a predetermined value or more, the inter-vehicle distance between the preceding vehicle ahead and the preceding vehicle is reduced, so the preceding vehicle must eventually decelerate. In such a case, if the host vehicle running below the speed of the preceding vehicle accelerates to follow the preceding vehicle, when the preceding vehicle subsequently decelerates, this time, You must follow and slow down. Therefore, in the first aspect, when the speed of the preceding vehicle ahead is lower than the speed of the preceding vehicle by a predetermined value or more, that is, when the inter-vehicle distance between the preceding vehicle ahead and the preceding vehicle is reduced, the preceding vehicle following control is performed. If the vehicle is performing acceleration, the preceding vehicle follow-up control is interrupted and the speed of the own vehicle is maintained even if the speed of the own vehicle is equal to or lower than the speed of the preceding vehicle. Therefore, after that, the host vehicle does not have to perform unnecessary acceleration and sudden deceleration.

  As a result, it is possible to prevent deterioration of fuel consumption due to useless acceleration and sudden deceleration, and it is possible to further suppress deterioration of fuel consumption when performing preceding vehicle following traveling. Note that, in the same way that the concept of fuel consumption is generally used even in an electric vehicle not equipped with fuel, “fuel consumption” in this specification is also a concept including fuel consumption in an electric vehicle.

  Moreover, in the structure of Claim 1, the present position information and speed information of another vehicle are acquired by vehicle-to-vehicle communication. In the inter-vehicle communication, the communication range is generally in the range of about several hundred m to 1 km in radius. Therefore, for example, when the relative speed between the preceding vehicle and the host vehicle is about 40 km / h, the THW (Time Head Way) for the preceding vehicle is about 90 seconds. Therefore, according to the configuration of claim 1, even if a vehicle that is too far away is traveling at a low speed or being stopped, the vehicle is treated as a preceding vehicle ahead and the preceding vehicle following traveling control is interrupted. There is nothing. Therefore, it is possible to avoid frequently interrupting the preceding vehicle following traveling control.

  The preceding vehicle follow-up travel device according to claim 2 is mounted on the vehicle, acquires information via a wireless communication device that receives information by road-to-vehicle communication, and causes the vehicle to follow the preceding vehicle. Follow-up control is performed. Further, based on the speed of the preceding vehicle determined by the preceding vehicle speed determining means and the speed information of the preceding preceding vehicle acquired by the other vehicle information acquiring means, the speed of the preceding preceding vehicle is higher than the speed of the preceding vehicle. Speed determining means for determining whether or not it is smaller than a predetermined value is provided. If the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is equal to or lower than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, the preceding vehicle follow-up Control is interrupted and acceleration is suppressed by maintaining the speed of the vehicle.

  Even in the situation where the distance between the preceding vehicle and the preceding vehicle is reduced, the speed of the own vehicle is equal to or lower than the speed of the preceding vehicle. Even under circumstances, the preceding vehicle follow-up control is interrupted and the speed of the own vehicle is maintained. Therefore, the own vehicle can be prevented from performing unnecessary acceleration and sudden deceleration. Accordingly, it is possible to prevent deterioration of fuel consumption due to unnecessary acceleration or sudden deceleration, and it is possible to further suppress deterioration of fuel consumption when performing preceding vehicle following traveling.

  According to the second aspect of the present invention, the current position information and speed information of the preceding vehicle ahead located in a predetermined distance ahead of the preceding vehicle in the traveling direction on the same road as the preceding vehicle are acquired by road-to-vehicle communication. This is possible, for example, by acquiring the current position information and speed information of the vehicle located at the point at a point within a predetermined distance ahead of the preceding vehicle on the same road as the preceding vehicle and transmitting it from the roadside device. become. According to the configuration of the second aspect, since the current position information and speed information of the preceding vehicle ahead located within a predetermined distance ahead of the traveling direction of the preceding vehicle are acquired and used, the preceding vehicle ahead running at low speed or stopped It is possible to avoid prohibiting acceleration by maintaining the speed of the vehicle from a position that is excessively far away.

  The preceding vehicle follow-up traveling device according to claim 3 is mounted on the vehicle, acquires information via a wireless communication device that receives information by road-to-vehicle communication, and causes the vehicle to follow the preceding vehicle. Follow-up control is performed. Further, the speed information, the position information, and the traveling direction information of the road vehicle detected by the roadside sensor, which are transmitted from the roadside base station by road-to-vehicle communication, are sequentially acquired by the other vehicle information acquisition means via the wireless communication device. And, from the current position of the preceding vehicle determined by the preceding vehicle position determining means and the traveling direction of the preceding vehicle determined by the traveling direction determining means, and the position information and the traveling direction information of the road vehicle acquired by the other vehicle information acquiring means, The preceding vehicle forward vehicle determining means determines whether or not the road vehicle is a preceding vehicle ahead vehicle positioned within a predetermined distance ahead of the preceding vehicle in the traveling direction. Further, based on the speed of the preceding vehicle determined by the preceding vehicle speed determining means and the speed information of the preceding vehicle ahead acquired by the other vehicle information acquiring means, the speed of the preceding vehicle ahead of the preceding vehicle is higher than the speed of the preceding vehicle. It is determined by the speed determination means whether or not it is smaller than a predetermined value. If the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is equal to or lower than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, the preceding vehicle follow-up Control is interrupted and acceleration is suppressed by maintaining the speed of the vehicle.

  According to the configuration of claim 3, in a situation where the distance between the preceding vehicle and the preceding vehicle is reduced, acceleration is performed if the preceding vehicle follow-up control is performed. Even under circumstances, the preceding vehicle follow-up control is interrupted and the speed of the own vehicle is maintained. Therefore, the own vehicle can be prevented from performing unnecessary acceleration and sudden deceleration. Accordingly, it is possible to prevent deterioration of fuel consumption due to unnecessary acceleration or sudden deceleration, and it is possible to further suppress deterioration of fuel consumption when performing preceding vehicle following traveling.

  The preceding vehicle follow-up traveling device according to claim 4 is mounted on the vehicle, acquires information via a wireless communication device that receives information by road-to-vehicle communication, and causes the vehicle to follow the preceding vehicle. Follow-up control is performed. In addition, the speed information, the position information, and the traveling direction information of the road vehicle received by the road base station from the second wireless communication device of the road vehicle, which are transmitted from the roadside base station by road-to-vehicle communication, are transmitted via the wireless communication device. Obtained sequentially by other vehicle information obtaining means. And, from the current position of the preceding vehicle determined by the preceding vehicle position determining means and the traveling direction of the preceding vehicle determined by the traveling direction determining means, and the position information and the traveling direction information of the road vehicle acquired by the other vehicle information acquiring means, The preceding vehicle forward vehicle determining means determines whether or not the road vehicle is a preceding vehicle ahead vehicle positioned within a predetermined distance ahead of the preceding vehicle in the traveling direction. Further, based on the speed of the preceding vehicle determined by the preceding vehicle speed determining means and the speed information of the preceding vehicle ahead acquired by the other vehicle information acquiring means, the speed of the preceding vehicle ahead of the preceding vehicle is higher than the speed of the preceding vehicle. It is determined by the speed determination means whether or not it is smaller than a predetermined value. If the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is equal to or lower than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, the preceding vehicle follow-up Control is interrupted and acceleration is suppressed by maintaining the speed of the vehicle.

  According to the configuration of claim 4, in the situation where the inter-vehicle distance between the preceding vehicle and the preceding vehicle is reduced, acceleration is performed if the preceding vehicle follow-up control is performed. Even under circumstances, the preceding vehicle follow-up control is interrupted and the speed of the own vehicle is maintained. Therefore, the own vehicle can be prevented from performing unnecessary acceleration and sudden deceleration. Accordingly, it is possible to prevent deterioration of fuel consumption due to unnecessary acceleration or sudden deceleration, and it is possible to further suppress deterioration of fuel consumption when performing preceding vehicle following traveling.

  As in claim 5, when the speed determination means makes an affirmative determination, the speed of the host vehicle detected by the host vehicle speed detection means is greater than the speed of the preceding vehicle determined by the preceding vehicle speed determination means. In this case, it is preferable that the preceding vehicle follow-up control is continued and the preceding vehicle follow-up control is continued even when the speed determination unit makes a negative determination.

  This is because even when the speed of the preceding vehicle is smaller than the speed of the preceding vehicle by a predetermined value or more, if the speed of the own vehicle is larger than the speed of the preceding vehicle, the own vehicle gradually approaches the preceding vehicle. This is because it is necessary to continue the preceding vehicle follow-up control and decelerate the host vehicle. Further, it is considered that the possibility that the own vehicle will perform unnecessary acceleration or sudden deceleration is low when the speed of the preceding vehicle is not smaller than the speed of the preceding vehicle by a predetermined value or more. Specifically, if the speed of the preceding vehicle is not smaller than the speed of the preceding vehicle by a predetermined value or more, it is considered that the inter-vehicle distance between the preceding vehicle and the preceding vehicle is difficult to reduce. The car is unlikely to have to decelerate by the amount of acceleration. Therefore, in such a case, even if the host vehicle travels following the preceding vehicle, it is unlikely that the host vehicle will perform unnecessary acceleration or sudden deceleration.

  In the configuration of claim 6, when the preceding vehicle follow-up control is interrupted and the affirmative determination is made by the speed determining means, and the own vehicle speed is equal to or lower than the preceding vehicle speed, the preceding vehicle follow-up control is performed. If the speed determination means makes an affirmative determination and the speed of the host vehicle is greater than the speed of the preceding vehicle, the preceding vehicle follow-up control is resumed and the speed determination means negates Also when it determines, preceding vehicle follow-up control is restarted.

  If the speed of the preceding vehicle has decreased or the speed of the preceding vehicle has increased, and the speed of the preceding vehicle has not decreased by a predetermined value or more than the speed of the preceding vehicle, as described above, It is considered that there is a low possibility that unnecessary acceleration or sudden deceleration will be performed even if following the above. Even if the speed of the preceding vehicle is smaller than the speed of the preceding vehicle by a predetermined value or more, if the speed of the host vehicle is higher than the speed of the preceding vehicle, follow-up traveling is performed as described above. Need to go and slow down. According to the configuration of the sixth aspect, the preceding vehicle follow-up control is resumed in the above-described case. Therefore, when the possibility of performing unnecessary acceleration or sudden deceleration is low or follow-up traveling is necessary, the preceding vehicle follow-up control is performed. Can be resumed.

  On the other hand, if the speed of the vehicle ahead of the preceding vehicle is smaller than the speed of the preceding vehicle by a predetermined value or more and the speed of the host vehicle is equal to or less than the speed of the preceding vehicle, as described above, it is useless to follow the preceding vehicle. It is conceivable to perform rapid acceleration or sudden deceleration. According to the configuration of the third aspect, the preceding vehicle follow-up control is continuously interrupted in the above-described case, so that the preceding vehicle follow-up control is not resumed until the possibility of performing unnecessary acceleration or sudden deceleration becomes low. can do.

  According to the configuration of the seventh aspect, the preceding vehicle follow-up traveling is performed using the above-described corrected approaching / separating state evaluation index KdB_c. The storage means stores a brake start threshold value formula and an acceleration control end threshold value formula. These are all equations obtained by adding an offset value to the brake discriminant. The brake discriminant is an expression showing the relationship between the corrected approaching / separating state evaluation index and the inter-vehicle distance at the time when the driver starts the brake operation. The brake start threshold value formula is a formula obtained by adding a brake offset value for reducing the corrected approach / separation state evaluation index for the same inter-vehicle distance to the brake discriminant formula, and the corrected approach / separation state evaluation index and the inter-vehicle distance at the start of the brake control. It is a formula which shows the relationship with distance. The acceleration control end threshold expression is an expression obtained by adding an acceleration offset value that further reduces the correction approach / separation state evaluation index for the same inter-vehicle distance to the brake discriminant expression than the brake offset value. It is a formula which shows the relation between the approaching / separating state evaluation index and the inter-vehicle distance. The current value calculation means sequentially calculates the current value of the corrected approaching / separating state evaluation index, and the threshold value calculation means calculates the brake start threshold value from the brake start threshold value expression and the current value of the inter-vehicle distance, and the acceleration control end threshold value expression And the acceleration control end threshold is calculated from the current value of the inter-vehicle distance. Then, the speed control means compares the current value of the corrected approaching / separating state evaluation index calculated by the current value calculation means with the brake start threshold value and the acceleration control end threshold value calculated by the threshold value calculation means. As a result of comparison, if the current value of the corrected approaching / separating state evaluation index is higher than the brake start threshold value, the brake is operated, and if the current value of the corrected approaching / separating state evaluation index is lower than the acceleration control end threshold value, the acceleration control is performed and corrected. If the current value of the approach / separation state evaluation index is between the brake start threshold value and the acceleration control end threshold value, the host vehicle is driven at a constant speed.

  According to this, since the preceding vehicle follow-up running is performed using the corrected approach / separation state evaluation index KdB_c, the follow-up running with less discomfort for the driver is possible. Further, according to the above configuration, the brake start threshold value and the acceleration control end threshold value are provided, and if the current value of the corrected approaching / separating state evaluation index is between the brake start threshold value and the acceleration control end threshold value, the speed is constant. Since the control is performed, the frequency of acceleration / deceleration decreases. Therefore, deterioration of fuel consumption can be suppressed.

  In the configuration of the eighth aspect, two threshold values of the friction brake start threshold value and the prime mover brake start threshold value are used as the brake start threshold value. The prime mover brake is an engine brake or a regenerative brake. The storage means stores a friction brake start threshold value formula and a motor brake start threshold value formula as brake start threshold values. The friction brake start threshold value formula is a formula showing the relationship between the corrected approach / separation state evaluation index and the inter-vehicle distance at the time of starting the operation of the friction brake, and the correction approach / separation state evaluation index for the same inter-vehicle distance as the brake discriminant is lowered. It is the formula which added the offset value for the 1st brake to be made. The prime mover brake start threshold value formula is a formula showing the relationship between the corrected approach / separation state evaluation index and the inter-vehicle distance at the start of the operation of the engine brake, and the corrected approach / separation state evaluation index for the same inter-vehicle distance is set in the brake discriminant. This is an expression in which a second brake offset value that is further lowered than the first brake offset value is added. The threshold value calculation means calculates three threshold values. That is, the friction brake start threshold value is calculated from the friction brake start threshold value formula and the current value of the inter-vehicle distance, the motor brake start threshold value is calculated from the motor brake start threshold value formula and the current value of the inter-vehicle distance, and the acceleration control end threshold value formula is An acceleration control end threshold is calculated from the current value of the inter-vehicle distance. The speed control unit compares the current value of the corrected approaching / separating state evaluation index calculated by the current value calculation unit with the friction brake start threshold, the prime mover brake start threshold, and the acceleration control end threshold calculated by the threshold calculation unit. As a result of the comparison, if the current value of the corrected approach / separation state evaluation index is higher than the friction brake start threshold value, the friction brake is activated, and the current value of the corrected approach / separation state evaluation index is between the friction brake start threshold value and the motor brake start threshold value. If this is the case, the prime mover brake is activated, and if the current value of the corrected approach / separation state evaluation index is lower than the acceleration control end threshold value, acceleration control is performed, and the current value of the corrected approach / separation state evaluation index is the brake start threshold value and acceleration control end threshold value. If it is between, the host vehicle is driven at a constant speed.

  According to the present invention, two types of braking are performed according to the current value of the corrected approaching / separating state evaluation index: a friction brake and a prime mover brake. When the driver himself / herself drives, it is normal to use the friction brake and the prime mover brake as appropriate. Accordingly, according to the present invention, the deceleration control during the follow-up traveling is less uncomfortable for the driver. Decelerates.

  According to the configuration of the ninth aspect, the brake start threshold value changing means can change the brake start threshold value according to the road surface condition determined by the road surface condition determining means, so that the deceleration start point is changed according to the road surface condition. Is possible.

  In the case of the ninth aspect, as in the tenth aspect, the input result of the input device in which the occupant of the own vehicle selects and inputs whether the road surface condition is high μ or low μ is obtained. The road surface condition determining means determines whether the road surface condition is high μ or low μ according to the input result acquired by the input result acquiring means, and includes a brake. The start threshold value changing means sets the brake start threshold value to a higher value when the road surface condition determining means determines that the road surface condition is high μ than when it is determined that the road surface condition is low μ. When it is determined that is low μ, it is preferable that the brake start threshold is set to a lower value than when high μ is determined. According to this, on the road surface of low μ where the braking distance becomes longer than the road surface of high μ, the deceleration start is set earlier than the case of high μ by setting the brake start threshold value to be lower than the case of high μ. Thus, it is possible to decelerate with sufficient margin for the deceleration of the preceding vehicle.

  According to another aspect of the present invention, the vehicle further includes a current position acquisition unit that sequentially acquires the current position of the host vehicle, and the preceding vehicle position determination unit includes the position information of the host vehicle acquired by the current position information acquisition unit and the inter-vehicle distance detection unit. It is preferable to determine the current position of the preceding vehicle from the detected inter-vehicle distance between the preceding vehicle and the own vehicle. According to this, even if the preceding vehicle does not have a device for performing inter-vehicle communication with the own vehicle and the current position information of the preceding vehicle cannot be obtained by inter-vehicle communication, the position of the own vehicle It becomes possible to determine the current position of the preceding vehicle from the information and the inter-vehicle distance detected by the autonomous sensor, for example. Therefore, versatility can be further improved.

  Since the driving support system according to claim 12 includes the preceding vehicle follow-up traveling device according to claim 3 mounted on a vehicle, it is possible to prevent deterioration of fuel consumption due to unnecessary acceleration or sudden deceleration, and to follow the preceding vehicle following travel. In what is performed, deterioration of fuel consumption can be further suppressed.

  Since the driving support system according to claim 13 includes the preceding vehicle follow-up traveling device according to claim 4 mounted on a vehicle, it is possible to prevent deterioration of fuel consumption due to unnecessary acceleration and sudden deceleration, and to follow the preceding vehicle following travel. In what is performed, deterioration of fuel consumption can be further suppressed.

1 is a block diagram showing a schematic configuration of a driving support system 100. FIG. It is a flowchart which shows an example of the flow of the acceleration limitation related process in vehicle control ECU10. It is a flowchart which shows an example of the flow of the preceding vehicle following travel control restart determination process in vehicle control ECU10. It is a schematic diagram for demonstrating the relative positional relationship and traveling state of the own vehicle O, the preceding vehicle P, and the preceding vehicle forward vehicle C in the conventional preceding vehicle following control. It is a graph for demonstrating the speed change of the own vehicle O and the preceding vehicle P in the conventional preceding vehicle follow-up control. It is a schematic diagram for demonstrating the relative positional relationship and traveling state of the own vehicle O, the preceding vehicle P, and the preceding vehicle forward vehicle C in the preceding vehicle following control of this embodiment. It is a graph for demonstrating the speed change of the own vehicle O and the preceding vehicle P in the preceding vehicle follow-up control of this embodiment. FIG. 10 is a schematic diagram for explaining a relative positional relationship and a traveling state of a host vehicle O, a preceding vehicle P, and a preceding vehicle forward vehicle C in a preceding vehicle follow-up control of a second modification. 10 is a graph for explaining a speed change of the host vehicle O and the preceding vehicle P in the preceding vehicle follow-up control in the second and third modified examples. FIG. 10 is a schematic diagram for explaining a relative positional relationship and a traveling state of a host vehicle O, a preceding vehicle P, and a preceding vehicle forward vehicle C in a preceding vehicle follow-up control of a third modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 illustrates a case where the preceding vehicle following traveling device of the present invention is applied to a driving support system 100. In FIG. 1, the whole structure of the driving assistance system 100 of this embodiment is shown. As shown in the figure, the driving support system 100 includes a VSC_ECU 1, a rudder angle sensor 2, a G sensor 3, a yaw rate sensor 4, an ENG_ECU 5, a navigation ECU 6, a radio communication device 7, a radar 8, an operation SW 9, and a vehicle control ECU 10. Composed.

  A VSC_ECU 1 shown in FIG. 1 controls a brake actuator (not shown) that applies a braking force to the host vehicle, and has a control function of VSC (Vehicle Stability Control (registered trademark)) that suppresses a side slip of the host vehicle. The VSC_ECU 1 receives information on the requested deceleration from the in-vehicle LAN, and controls the brake actuator so that the requested deceleration is generated in the host vehicle. Further, the VSC_ECU 1 transmits information on the speed (vehicle speed) Vo of the own vehicle and the brake pressure to the in-vehicle LAN. The steering angle sensor 2 is a sensor that detects information on the steering angle of the steering of the host vehicle, and transmits information on the detected steering angle to the in-vehicle LAN.

  The G sensor 3 is an acceleration sensor that detects acceleration (front-rear G) generated in the front-rear direction of the host vehicle and acceleration (lateral G) generated in the lateral (left-right) direction, and information on the detected front-rear G and lateral G is detected. Is transmitted to the in-vehicle LAN. The yaw rate sensor 4 is a sensor that detects an angular velocity (yaw rate) about the vertical axis of the host vehicle, and transmits information on the detected yaw rate to the in-vehicle LAN. The ENG_ECU 5 receives information on the requested acceleration from the in-vehicle LAN, and controls a throttle actuator (not shown) so that the host vehicle generates the requested acceleration. In addition, when the information on the requested deceleration is received, the engine brake is generated by controlling the throttle actuator.

  The navigation ECU 6 is a control device for the in-vehicle navigation device, and as a navigation function based on the current position and traveling direction of the vehicle detected by the position detector 61 described later and map data read from the map data input device 62 described later. The various processes are executed.

  The position detector 61 is a geomagnetic sensor that detects geomagnetism, a gyroscope that detects an angular velocity around the vertical direction of the host vehicle, a distance sensor that detects a moving distance of the host vehicle, and a current position of the vehicle based on radio waves from a satellite. Based on information obtained from each sensor such as a GPS receiver for GPS (global positioning system) for detecting the vehicle, the current position and the traveling direction of the vehicle are sequentially detected. Since these sensors have errors of different properties, they are configured to be used while being complemented by a plurality of sensors. Depending on the accuracy of each sensor, the position detector 61 may be configured as a part of the above-described ones, or a sensor other than those described above may be used. For example, the current position is represented by latitude and longitude, and the traveling direction is represented by an azimuth angle with reference to north.

  The map data input device 62 is a device that is loaded with a storage medium (not shown) and inputs map data stored in the storage medium. The map data includes link data indicating roads and node data. The link data includes a unique number (link ID) that identifies the link, a link length that indicates the length of the link, a link direction, a link orientation, link start and end node coordinates (latitude / longitude), road name, road type, It consists of data such as traffic attributes, road width, number of lanes, presence / absence of right / left turn lanes, the number of lanes, and speed regulation values. On the other hand, the node data includes a node ID, a node coordinate, a node name, and a link ID of a link connected to the node, each node having a unique number for each node where roads on the map intersect, merge and branch. It consists of each data such as ID and intersection type.

  Note that the map data is not limited to the configuration using the storage medium mounted on the map data input device 62, but the map data stored in the server device is used via a server communication unit (not shown). It is good also as composition to do.

  The wireless communication device 7 includes a transmission / reception antenna, and distributes information on the own vehicle and receives information on the other vehicle by wireless communication with other vehicles existing around the position of the own vehicle without going through the telephone network (that is, Vehicle-to-vehicle communication). It is assumed that the communication range of inter-vehicle communication is limited to a predetermined range (preferably a radius of about several hundred m to 1 km). For example, in the case of wireless communication using a 700 MHz band radio wave, vehicle-to-vehicle communication is performed with a partner vehicle existing in a radius range of about 1 km around the vehicle position, for example, and a 5.9 GHz band radio wave. In the case of wireless communication using the vehicle, vehicle-to-vehicle communication is performed with a partner vehicle existing in a range of, for example, a radius of about 500 m with the vehicle position at the center.

  It is assumed that the wireless communication device 7 transmits vehicle information such as the own vehicle speed Vo, the current position of the own vehicle, and the traveling direction obtained from the in-vehicle LAN at a constant transmission cycle such as every 100 msec. In addition, the wireless communication device 7 receives vehicle information of another vehicle transmitted from the wireless communication device 7 included in the driving support system 100 mounted on another vehicle that is a vehicle other than the host vehicle. The wireless communication device 7 outputs the received information to the vehicle control ECU 10.

  The radar 8 is, for example, a well-known laser radar that irradiates a predetermined range ahead of the host vehicle with laser light, receives the reflected light, receives the inter-vehicle distance D with the preceding vehicle, the relative speed Vr with the preceding vehicle, A deviation amount (lateral deviation amount) between the own vehicle width center axis and the center axis of the preceding vehicle is detected and output to the vehicle control ECU 10. The vehicle control ECU 10 may detect the inter-vehicle distance D with the preceding vehicle, the relative speed Vr with the preceding vehicle, the deviation amount (lateral deviation amount) between the center width of the host vehicle and the center axis of the preceding vehicle, and the like. Good. In the present embodiment, the following description will be continued assuming that the detection is performed by the vehicle control ECU 10 based on the signal of the radar 8. The operation SW 9 is a switch group operated by the driver of the host vehicle, and operation information of the switch group is output to the vehicle control ECU 10.

  The vehicle control ECU 10 is mainly configured as a microcomputer, and each includes a known CPU, ROM, RAM, I / O, and a bus connecting them. The vehicle control ECU 10 executes various processes based on various information input from the VSC_ECU 1, the steering angle sensor 2, the G sensor 3, the yaw rate sensor 4, the ENG_ECU 5, the navigation ECU 6, the radio communication device 7, the radar 8, and the operation SW 9. . The vehicle control ECU 10 corresponds to the preceding vehicle following traveling device in the claims.

A memory such as a ROM of the vehicle control ECU 10 stores three threshold expressions: a friction brake start threshold expression, an engine brake start threshold expression, and an acceleration control end threshold expression. Therefore, the vehicle control ECU 10 corresponds to the storage means in the claims. Each of these threshold expressions is an expression obtained by adding an offset value to the brake discriminant. Formula 3 shows the brake discriminant.

  This brake discriminant is an expression showing the relationship between KdB_c and the inter-vehicle distance D at the time when the driver starts the brake operation. In Expression 3, a, b, and c are all constants and are determined based on experiments. . A means a in Formula 2. a, b, and c are, for example, 0.2, −22.66, and 74.71, respectively.

Since the brake discriminant is an expression shown in Expression 3, the friction brake start threshold expression, the engine brake start threshold expression, and the acceleration control end threshold expression are all expressions shown in Expression 4. Δc in Equation 4 is an offset value. As this offset value, the first brake offset value Δc1 is used in the friction brake start threshold equation, and the second brake offset value Δc2 is used in the engine brake start threshold equation, and the acceleration control ends. In the threshold type, an acceleration offset value Δc3 is used. These offset values Δc1, Δc2, and Δc3 are, for example, −3 dB, −4 dB, and −6 dB.

  Due to the magnitude relationship of the offset values, the corrected approach / separation state evaluation index KdB_c at the same inter-vehicle distance D decreases in the order of the brake discriminant formula, the friction brake start threshold formula, the engine brake start threshold formula, and the acceleration control end threshold formula.

  The vehicle control ECU 10 performs preceding vehicle follow-up running control using various devices connected by an in-vehicle LAN or the like. The preceding vehicle follow-up control starts when the driver operates the operation SW9 to give an instruction to start the preceding vehicle follow-up control, and the preceding vehicle follow-up control ends when the driver finishes the operation. Further, based on the signal from the radar 8, the distance from the following vehicle that is detected by the radar 8 when the preceding vehicle following control start instruction is issued is detected, and this detected distance (that is, the following vehicle and the following vehicle) is detected. For example, the initial inter-vehicle distance) is set as the target inter-vehicle distance Dt.

  Hereinafter, the contents of the preceding vehicle following travel control will be described in detail. The vehicle control ECU 10 sequentially calculates the current value of KdB_c during the preceding vehicle following traveling control. Therefore, vehicle control ECU10 is equivalent to the present value calculation means of a claim. KdB_c is calculated from the evaluation index calculation formula shown in Formula 2. Therefore, to calculate the current value of KdB_c, it is necessary to determine the relative speed Vr, the speed Vp of the preceding vehicle, and the inter-vehicle distance D. The relative speed Vr and the inter-vehicle distance D are determined based on a signal from the radar 8, for example. The speed Vp of the preceding vehicle is calculated from the relative speed Vr and the host vehicle speed Vo from the VSC_ECU 1. Then, by substituting these into Equation 2, the current value of KdB_c is calculated sequentially. Therefore, the vehicle control ECU 10 corresponds to the inter-vehicle distance detection means, the relative speed determination means, and the preceding vehicle speed determination means.

  The speed Vp of the preceding vehicle may be obtained sequentially from the preceding vehicle via the wireless communication device 7 when the preceding vehicle is a vehicle equipped with the driving support system 100. In this case, the relative speed Vr may be calculated sequentially from the host vehicle speed Vo sequentially acquired from the VSC_ECU 1 and the speed Vp of the preceding vehicle sequentially acquired via the wireless communication device 7. The inter-vehicle distance D may be determined by calculating a distance increase / decrease from the target inter-vehicle distance Dt based on the sequentially calculated relative speed Vr. In addition, it is good also as a structure which uses the stable inter-vehicle distance in Japanese Patent Application No. 2011-99199 for which this applicant applied previously instead of the target inter-vehicle distance Dt.

  The vehicle control ECU 10 sequentially calculates three threshold values, that is, a friction brake start threshold value, an engine brake start threshold value, and an acceleration control end threshold value during the preceding vehicle following travel control. Therefore, the vehicle control ECU 10 corresponds to the threshold value calculation means in the claims. These are calculated from three threshold expressions stored in the memory, that is, a friction brake start threshold expression, an engine brake start threshold expression, an acceleration control end threshold expression, and a current value of the inter-vehicle distance D.

  The vehicle control ECU 10 compares the target inter-vehicle distance Dt with the current inter-vehicle distance D during the preceding vehicle following travel control, and if the current inter-vehicle distance D is shorter than the target inter-vehicle distance Dt, the current value of KdB_c. The VSC_ECU 1 is instructed to operate the friction brake regardless of what value is.

On the other hand, when the current inter-vehicle distance D is longer than the target inter-vehicle distance Dt, the current value of KdB_c is compared with the friction brake start threshold, the engine brake start threshold, and the acceleration control end threshold. As a result of the comparison, there are the following results (1) to (4). That is, (1) when the current value of KdB_c is higher than the friction brake start threshold, (2) when the current value of KdB_c is between the friction brake start threshold and the engine brake start threshold, (3) the current value of KdB_c is When it is between the brake start threshold value and the acceleration control end threshold value, (4) the current value of the corrected approaching / separating state evaluation index may be lower than the acceleration control end threshold value. In the case of (1), the friction brake is operated, in the case of (2), the engine brake is operated, in the case of (3), the host vehicle is driven at a constant speed, and in the case of (4), the acceleration is accelerated. Take control. Therefore, the vehicle control ECU 10 corresponds to the speed control means in the claims. The required acceleration / deceleration GDp when the host vehicle is decelerated or accelerated is calculated by, for example, the following formula 5. A positive value is the required acceleration, and a negative value is the required deceleration.

  Vr_t in Equation 5 is a target relative speed obtained by substituting KdB_c at the current inter-vehicle distance D obtained from the brake discriminant into Equation 2. T is a divisor for converting the difference between the current relative speed Vr of the host vehicle and the target relative speed Vr_t into the required acceleration / deceleration GDp, and is set as appropriate.

  Further, the vehicle control ECU 10 determines whether or not to limit the acceleration of the own vehicle by interrupting the preceding vehicle follow-up travel control based on the vehicle information of other vehicles sequentially acquired via the wireless communication device 7, Acceleration restriction related processing for performing control according to the determination result is performed. Hereinafter, this acceleration restriction related process will be described with reference to the flow of FIG. FIG. 2 is a flowchart showing an example of a flow of acceleration restriction related processing in the vehicle control ECU 10. The flow in FIG. 2 is started when, for example, the preceding vehicle following traveling control is started, and is ended when the preceding vehicle following traveling control is ended.

  First, in step S1, it is determined whether vehicle information (specifically, vehicle speed, current position, and traveling direction information) transmitted from the wireless communication device 7 of another vehicle has been acquired. For example, what is necessary is just to set it as the structure which determines with acquiring the vehicle information of another vehicle based on the vehicle information received with the wireless communication apparatus 7 having been input into vehicle control ECU10. Therefore, vehicle control ECU10 is equivalent to the other vehicle information acquisition means of a claim.

  And when it determines with having acquired the vehicle information of another vehicle (it is YES at step S1), it moves to step S2. If it is determined that the vehicle information of the other vehicle is not acquired (NO in step S1), the flow of step S1 is repeated.

  In step S2, a preceding vehicle forward vehicle determination process is performed, and the process proceeds to step S3. In the preceding vehicle forward vehicle determination process, the other vehicle from which the acquired vehicle information is transmitted is a vehicle located in front of the preceding vehicle on the same road as the preceding vehicle of the own vehicle (that is, the preceding vehicle ahead vehicle). Determine whether or not. Therefore, the vehicle control ECU 10 corresponds to the preceding vehicle forward vehicle determining means in the claims. Specifically, from the current position and traveling direction of the preceding vehicle and the current position and traveling direction of the other vehicle from which the vehicle information is transmitted and the map data, the other vehicle from which the vehicle information is transmitted is on the same road as the preceding vehicle. Judgment is made by determining whether or not the vehicle is located in the forward direction of the preceding vehicle.

  The same road may be all lanes in the same traveling direction as the lane in which the preceding vehicle is traveling in a section without a branch (that is, the same link) in the middle, or only in the lane in which the preceding vehicle is traveling. There may be. In addition, the same road may be all lanes in the same traveling direction as the lane in which the preceding vehicle is traveling, with the same road name as the road in which the preceding vehicle is traveling, or the lane in which the preceding vehicle is traveling It may be only.

  In the preceding vehicle forward vehicle determination process, when guidance route data can be acquired from the navigation ECU 6, vehicles on this guidance route among vehicles positioned in the forward direction of the preceding vehicle on the same road as the preceding vehicle of the host vehicle Only the vehicle ahead of the preceding vehicle may be used. A road in the same direction as the traveling direction of the preceding vehicle on the guide route may be the same road.

  Here, regarding the current position and the traveling direction of the preceding vehicle, the preceding vehicle is a vehicle on which the driving support system 100 is mounted, and the vehicle information of the preceding vehicle can be acquired from the preceding vehicle via the wireless communication device 7. In such a case, the configuration may be determined from vehicle information acquired from the preceding vehicle. Further, when the preceding vehicle does not have the driving support system 100 and vehicle information cannot be acquired from the preceding vehicle by inter-vehicle communication, the following may be performed.

  For example, the current position of the preceding vehicle may be determined from the current position of the own vehicle acquired from the position detector 61 and the inter-vehicle distance D from the preceding vehicle detected based on the radar 8 signal. The traveling direction of the preceding vehicle may be determined by analogy with the traveling direction of the host vehicle. Therefore, the vehicle control ECU 10 corresponds to the preceding vehicle position determination means and the current position acquisition means in the claims. Map data is acquired from the map data input device 62. Therefore, vehicle control ECU10 is equivalent to the map data acquisition means of a claim.

  In the present embodiment, the configuration in which the information on the traveling direction is also acquired to perform the preceding vehicle forward vehicle determination process is shown. However, the present invention is not limited to this, and the preceding vehicle preceding vehicle determination process is not necessarily acquired. It is good also as composition which performs. Specifically, in the case where a plurality of pieces of position information (for example, position information of two points) sequentially detected by the position detector 61 including the current position is transmitted via the wireless communication device 7, the other vehicle What is necessary is just to set it as the structure which estimates the advancing direction of another vehicle from the acquired several positional information by vehicle control ECU10, and uses it for a preceding vehicle forward vehicle determination process. In the case where the traveling direction information is not acquired, the traveling direction information may not be detected by the position detector 61 and the traveling direction information may not be transmitted from the wireless communication device 7.

  If it is determined in step S3 that the preceding vehicle is ahead in the preceding vehicle determination process (YES in step S3), the process proceeds to step S4. If it is determined in the preceding vehicle forward vehicle determination process that the vehicle is not a preceding vehicle ahead (NO in step S3), the flow returns to step S1 and the flow is repeated.

  In step S4, based on the speed Vp of the preceding vehicle and the speed Vc of the preceding vehicle ahead, it is determined whether or not the speed Vc of the preceding vehicle ahead is smaller than the speed Vp of the preceding vehicle by a predetermined value or more. Therefore, the vehicle control ECU 10 corresponds to the speed determination means in the claims. The predetermined value here is a value that can be arbitrarily set. For example, the predetermined value may be 0, and when the predetermined value is 0, it is determined whether or not the speed of the preceding vehicle is lower than the speed of the preceding vehicle. The speed Vp of the preceding vehicle may be determined as described above, and the information on the vehicle speed acquired from the preceding vehicle ahead may be used as the speed Vc of the preceding vehicle ahead. Note that the predetermined value is preferably set to a value greater than or equal to the degree in which the preceding vehicle gradually approaches the preceding vehicle when the preceding vehicle continues to travel. For example, the predetermined value may be set to 5 [km / h].

  If it is determined that the speed Vc of the preceding vehicle ahead is smaller than the speed Vp of the preceding vehicle by a predetermined value or more (YES in step S4), the process proceeds to step S6. If it is determined that the speed Vc of the preceding vehicle ahead is not smaller than the speed Vp of the preceding vehicle by a predetermined value or more (NO in step S4), the process proceeds to step S5. In step S5, the preceding vehicle following traveling control is continued, and the flow returns to step S1 to repeat the flow. If it is determined in step S5 that the speed Vc of the preceding vehicle ahead is smaller than the speed Vp of the preceding vehicle by a predetermined value or more (in this example, Vp ≧ Vd + 5 [km / h]) The limit value is a larger value of the speed Vo of the host vehicle and the speed Vc of the preceding vehicle ahead within a range not exceeding the set vehicle speed. If it is determined that the speed Vc of the preceding vehicle ahead is not smaller than the speed Vp of the preceding vehicle by a predetermined value or more (in this example, Vp <Vd + 5 [km / h]), The speed limit value is, for example, the speed Vp + 5 [Km / h] of the preceding vehicle.

  In step S6, based on the speed Vp of the preceding vehicle and the speed Vo of the own vehicle, it is determined whether or not the speed Vo of the own vehicle is equal to or lower than the speed Vp of the preceding vehicle. The speed Vo of the host vehicle is detected based on a signal transmitted from the VSC_ECU1. Therefore, the vehicle control ECU 10 corresponds to the vehicle speed detection means in the claims.

  And when it determines with the speed Vo of the own vehicle being below the speed Vp of a preceding vehicle (it is YES at step S6), it moves to step S7. If it is determined that the speed Vo of the host vehicle is higher than the speed Vp of the preceding vehicle (NO in step S6), the process proceeds to step S5.

  In step S7, an acceleration limiting process is performed, and the process proceeds to step S8. In the acceleration limiting process, the preceding vehicle following traveling control is interrupted and the acceleration is suppressed by maintaining the speed Vo of the host vehicle. That is, the speed limit value is the speed Vo of the own vehicle at the time of interruption. Maintaining the speed Vo of the host vehicle may be, for example, a configuration in which the current speed Vo of the host vehicle is maintained (at the time when acceleration restriction processing is started), or may be the speed Vo of the host vehicle used in step S6. It is good also as a structure to maintain.

  In step S8, a preceding vehicle following travel control restart determination process is performed, and the process proceeds to step S9. Here, an outline of the preceding vehicle following travel control restart determination process will be described with reference to the flowchart of FIG. FIG. 3 is a flowchart showing an example of a flow of a preceding vehicle following travel control restart determination process in the vehicle control ECU 10.

  First, in step S81, similarly to step S1, it is determined whether vehicle information transmitted from the wireless communication device 7 of another vehicle has been acquired. And when it determines with having acquired the vehicle information of another vehicle (it is YES at step S81), it moves to step S82. If it is determined that the vehicle information of the other vehicle has not been acquired (NO in step S81), the process proceeds to step S84.

  In step S82, the same preceding preceding vehicle information acquisition determination process is performed, and the process proceeds to step S83. In the same preceding vehicle forward vehicle information acquisition determination process, it is determined whether or not vehicle information from the same vehicle (that is, the same target) as the vehicle determined to be the preceding vehicle forward vehicle in step S3 has been acquired. As a specific example, identification information (such as a vehicle ID) that can identify a transmission source vehicle is added to vehicle information transmitted by inter-vehicle communication, and the same target is obtained based on this identification information. What is necessary is just to set it as the structure which determines whether the vehicle information from is acquired.

  In step S83, when it is determined in the same preceding vehicle forward vehicle information acquisition determination process that vehicle information has been acquired from the same target (YES in step S83), the process proceeds to step S85. Moreover, when it determines with not acquiring vehicle information from the same object by the same preceding vehicle front vehicle information acquisition determination process (it is NO at step S83), it moves to step S84.

  In step S84, it is determined whether or not a predetermined time has elapsed since the vehicle information was acquired from the vehicle determined to be the preceding vehicle in step S3 (that is, time-out). For example, by starting counting of a timer (not shown) at the time when vehicle information is acquired from the vehicle determined to be a preceding vehicle ahead in step S3, the elapsed time from the time is measured, and whether or not a timeout has occurred is determined. What is necessary is just to set it as the structure to determine. Note that the predetermined time referred to here is a time that can be arbitrarily set, and may be 1 s, for example.

  If it is determined that a timeout has occurred (YES in step S84), the process proceeds to step S86. On the other hand, if it is determined that it is not a timeout (NO in step S84), the flow returns to step S81 and the flow is repeated. Note that the time-out is not only the time elapsed since the vehicle information was acquired from the vehicle determined to be a preceding vehicle ahead in step S3, but also the time elapsed since the preceding vehicle following travel control was interrupted, for example. It is good also as a structure to determine based on.

  In step S85, similarly to step S4, it is determined whether or not the speed Vc of the preceding vehicle ahead is smaller than the speed Vp of the preceding vehicle by a predetermined value or more. If it is determined that the speed Vc of the preceding vehicle ahead is smaller than the speed Vp of the preceding vehicle by a predetermined value or more (YES in step S85), the process proceeds to step S87. If it is determined that the speed Vc of the preceding vehicle ahead is not smaller than the speed Vp of the preceding vehicle by a predetermined value or more (NO in step S85), the process proceeds to step S86. In step S86, it is determined that the preceding vehicle following traveling control is resumed, and the process proceeds to step S9.

  In step S87, similarly to step S6, it is determined whether or not the speed Vo of the host vehicle is equal to or lower than the speed Vp of the preceding vehicle. And when it determines with the speed Vo of the own vehicle being below the speed Vp of a preceding vehicle (it is YES at step S87), it moves to step S88. If it is determined that the speed Vo of the host vehicle is higher than the speed Vp of the preceding vehicle (NO in step S87), the process proceeds to step S86. In step S88, it is determined that the interruption of the preceding vehicle following traveling control is to be continued, and the process proceeds to step S9.

  Returning to FIG. 2, if it is determined in step S9 that the preceding vehicle following traveling control is to be restarted in the preceding vehicle following traveling control restart determination process (YES in step S9), the process proceeds to step S10. If it is determined in the preceding vehicle following traveling control restart determination process that the preceding vehicle following traveling control is interrupted (NO in step S9), the flow returns to step S8 and the flow is repeated. In step S10, the preceding vehicle follow-up running control is resumed, the process returns to step S1, and the flow is repeated.

  Here, the effect in this invention is demonstrated concretely using FIGS. 4-7. First, specific control of conventional preceding vehicle following control will be described. FIG. 4 is a schematic diagram for explaining the relative positional relationship and traveling state of the host vehicle O, the preceding vehicle P, and the preceding vehicle forward vehicle C in the conventional preceding vehicle following control. FIG. 5 is a graph for explaining speed changes of the own vehicle O and the preceding vehicle P in the conventional preceding vehicle following control. In the conventional preceding vehicle follow-up control, the description will be made assuming that the own vehicle O follows the target with a constant inter-vehicle distance and the same speed with respect to the preceding vehicle P within a range not exceeding the set vehicle speed Vm.

  In FIG. 4A, the host vehicle O is traveling with respect to the preceding vehicle P so as to have a constant inter-vehicle distance and the same speed (Vo = Vp). Further, the preceding vehicle C ahead is involved in a traffic jam and is stopped. From this state, when the preceding vehicle P accelerates beyond the speed Vc of the preceding vehicle forward vehicle C beyond a predetermined value (for example, Vc + 5 km / h), the own vehicle O accelerates following the preceding vehicle P. (See FIG. 4B). Then, the own vehicle O continues to follow the preceding vehicle P (see FIG. 4C).

  After that, when the preceding vehicle P approaches the preceding vehicle C ahead of the vehicle, the vehicle suddenly decelerates (see FIG. 4D), and the host vehicle O also follows and suddenly decelerates (see FIG. 4E). Become. In this case, since the own vehicle O follows the preceding vehicle P at a certain inter-vehicle distance, it suddenly decelerates and approaches the preceding vehicle P very much (see FIG. 4F), causing the driver to feel fear. There is a possibility that. Further, since the own vehicle O follows the preceding vehicle P in a range not exceeding the set vehicle speed Vm, the own vehicle O performs acceleration / deceleration in the same manner as the preceding vehicle P as shown in FIG.

  Next, specific control of the preceding vehicle follow-up control of this embodiment will be described. FIG. 6 is a schematic diagram for explaining the relative positional relationship and traveling state of the host vehicle O, the preceding vehicle P, and the preceding vehicle forward vehicle C in the preceding vehicle following control of the present embodiment. FIG. 7 is a graph for explaining the speed change of the host vehicle O and the preceding vehicle P in the preceding vehicle following control of the present embodiment. In the preceding vehicle follow-up control of the present embodiment, the own vehicle O is described as controlling the preceding vehicle P so as to follow the target at a constant inter-vehicle distance and the same speed within a range not exceeding the set vehicle speed Vm. I do.

  FIG. 6 (A) is the same state as FIG. 4 (A), and the preceding vehicle C ahead is caught in a traffic jam and is stopped. From this state, when the preceding vehicle P accelerates beyond a speed Vc of the preceding vehicle forward vehicle C beyond a predetermined value (for example, Vc + 5 km / h), in the conventional example of FIG. Accelerating following. However, in the example of FIG. 6, the own vehicle O does not accelerate following the preceding vehicle P (see FIG. 6B). In the state of FIG. 6 (B), the host vehicle O follows the preceding vehicle P. Therefore, when the preceding vehicle P accelerates, the speed Vo of the host vehicle O is equal to or lower than the speed Vp of the preceding vehicle P. It is. Accordingly, the preceding vehicle follow-up control is interrupted, and the speed Vo of the host vehicle O is maintained at a constant speed, and acceleration is suppressed (see FIGS. 6B and 6C).

  Thereafter, the vehicle suddenly decelerates when the preceding vehicle P approaches the preceding vehicle C (see FIG. 6D), and when the speed Vp of the preceding vehicle P is reduced to the speed Vo of the own vehicle O, the own vehicle O The preceding vehicle follow-up control for the preceding vehicle P is resumed. When the preceding vehicle follow-up control is resumed, the own vehicle O also follows the preceding vehicle P and decelerates. However, since the vehicle does not accelerate following the preceding vehicle P, it is not necessary to perform rapid deceleration. Further, since the preceding vehicle follow-up control is interrupted and the vehicle travels at a constant speed, the vehicle can be decelerated with a margin in the inter-vehicle distance with respect to the preceding vehicle P (see FIG. 6E). Therefore, unlike the example of FIG. 4F, the host vehicle O can be stopped without being very close to the preceding vehicle P (see FIG. 6F).

  Thus, according to the configuration of the present embodiment, the host vehicle O is provided with a speed limit (see the dotted line in the figure) as shown in FIG. . Moreover, useless acceleration can be prevented by not performing useless acceleration. In addition, according to the configuration of the present embodiment, the preceding vehicle follow-up control can be resumed when the possibility of performing unnecessary acceleration or rapid deceleration is low or when unnecessary acceleration / deceleration is not performed. As a result, it is possible to prevent deterioration of fuel consumption due to useless acceleration and sudden deceleration, and it is possible to further suppress deterioration of fuel consumption when performing preceding vehicle following traveling.

  Further, according to the configuration of the present embodiment, in the preceding vehicle following control, the friction brake start threshold value, the engine brake start threshold value formula, the acceleration control end threshold value formula is used, and the friction brake start threshold value, the engine brake start threshold value, the acceleration control is used. The end threshold is calculated sequentially. A constant speed region is set between the engine brake start threshold value and the acceleration control end threshold value. If the current value of KdB_c is in the constant speed region, constant speed control is performed. As a result of the ability to perform constant speed control, the frequency of acceleration / deceleration decreases, so that deterioration in fuel consumption can be further suppressed.

  Furthermore, in this embodiment, two types of brake control, friction brake and engine brake, are possible as brake control. Since the driver usually uses the friction brake and the engine brake properly when driving, according to the present embodiment, the deceleration control during the follow-up driving is more uncomfortable for the driver. Less deceleration.

  Moreover, although the above-mentioned embodiment showed the structure which uses the vehicle information of the other vehicle obtained by vehicle-to-vehicle communication, it does not necessarily restrict to this. For example, it is good also as a structure which uses the vehicle information of the preceding vehicle ahead vehicle obtained by the road-to-vehicle communication between on-road machines.

  The speed of the vehicle located at the installation point of the detector from the detector installed in front of a predetermined distance (preferably several hundred m to 1 km) in the traveling direction of the road on the side where the road machine is installed. In addition, a configuration (modification example 1) that acquires position information may be used. Here, the detector may be configured to transmit information on the detected speed and position to a road device by a wireless communication device (not shown).

  In addition, the detector is assumed to be installed on the roadside so as to detect only the speed and position of a vehicle traveling in the same lane in the traveling direction as the road on which the roadside machine is installed. This means that if the detector detects the speed of the vehicle using, for example, a radar, the radar detection range is included up to the same lane in the traveling direction as the side where the road equipment is installed, while the road equipment is installed. What is necessary is just to implement | achieve by limiting to the range which does not include the lane of the opposite direction to the done side. The position information may be configured to use the position (latitude / longitude coordinates) of the detector installation point.

  The road-to-vehicle communication between the wireless communication device 7 and the road machine is a communication range so that a vehicle traveling on a lane whose traveling direction is opposite to that of the road on which the road machine is installed is not included in the communication range. Is performed by limited spot communication. As an example, an optical beacon or a radio beacon may be used. With the above configuration, it is possible to acquire vehicle information of a vehicle corresponding to a preceding vehicle ahead within a predetermined distance (for example, within about several hundred m to 1 km) for the host vehicle that performs road-to-vehicle communication with a road device. .

  According to the configuration of the first modification, there is an advantage that the vehicle control ECU 10 does not need to perform the preceding vehicle forward vehicle determination process. On the other hand, the configuration using the vehicle information of other vehicles obtained by inter-vehicle communication has an advantage that the acceleration restriction related process can be executed even in a place where there is no road device or detector.

  In addition, as a configuration using vehicle information of a preceding vehicle ahead obtained by road-to-vehicle communication with a road machine, a configuration as shown in the following modified example 2 may be used. Here, the modification 2 is demonstrated using FIG.8 and FIG.9.

  In the second modification, a roadside base station 200 capable of performing road-to-vehicle communication with the wireless communication device 7 of the driving support system 100 is used as a road device. For example, the roadside base station 200 transmits information using wireless communication whose communication range is wider than the communication range of an optical beacon or a radio beacon. As an example, the information may be transmitted using wireless communication using a 700 MHz band radio wave with a communication range of about several hundred m to 1 km.

  The roadside base station 200 receives information transmitted from the roadside sensor 300 by wireless communication, for example. The roadside sensor 300 is installed on the roadside, for example, and detects information on the speed, position, and traveling direction of a vehicle traveling in the same lane as the traveling side of the roadside sensor 300 on the road in contact with the roadside.

  This is because when the roadside sensor 300 detects the speed of the vehicle by, for example, a radar, the radar detection range includes the same lane in the traveling direction as the roadside sensor 300 is installed. What is necessary is just to implement | achieve by limiting to the range which does not include the lane of the reverse direction to the side in which 300 was installed. Further, the position information may be configured to use the position (latitude / longitude coordinates) of the installation point of the roadside sensor 300, and the information on the traveling direction is the progress of the lane on the side where the roadside sensor 300 is installed. A configuration using a direction (an azimuth angle with respect to the north) may be used.

  In the second modification, vehicle information transmitted from the roadside base station 200 is received by the wireless communication device 7 and output to the vehicle control ECU 10. The vehicle information transmitted from the roadside base station 200 is information on the speed, position, and traveling direction of the vehicle detected by the roadside sensor 300. The vehicle control ECU 10 acquires vehicle information input from the wireless communication device 7 and performs a preceding vehicle forward vehicle determination process.

  In the preceding vehicle forward vehicle determination process of the modified example 2, it is determined whether or not the other vehicle in which the vehicle information acquired by the vehicle control ECU 10 is detected by the roadside sensor 300 is the aforementioned preceding vehicle forward vehicle. Specifically, from the current position and traveling direction of the preceding vehicle, the position information and traveling direction information included in the acquired vehicle information, and map data, the other vehicle from which the vehicle information is detected is on the same road as the preceding vehicle. Judgment is made by determining whether or not the vehicle is positioned in the forward direction of the preceding vehicle in the same manner as described above. Then, according to the determination result, the same process as the acceleration restriction related process is performed.

  Note that the current position and the traveling direction of the preceding vehicle may be determined by the vehicle control ECU 10 as described above. Therefore, the vehicle control ECU 10 corresponds to the traveling direction determination means in the claims.

  Here, the effect in the modification 2 is demonstrated using FIG.8 and FIG.9. FIG. 8 is a schematic diagram for explaining the relative positional relationship and the running state of the host vehicle O, the preceding vehicle P, and the preceding vehicle forward vehicle C in the preceding vehicle following control of the second modification. FIG. 9 is a graph for explaining speed changes of the host vehicle O and the preceding vehicle P in the preceding vehicle following control of the second modification. In the preceding vehicle follow-up control of the second modification, the own vehicle O is described as controlling the preceding vehicle P so as to follow the target at a constant inter-vehicle distance and the same speed within a range not exceeding the set vehicle speed Vm. I do.

  The modified example 2 has the same configuration except that the vehicle information of the vehicle ahead of the preceding vehicle is acquired by inter-vehicle communication or acquired by road-to-vehicle communication. Therefore, from the state of FIG. 8A in which the preceding vehicle C is caught in a traffic jam and stopped, the preceding vehicle P accelerates beyond the speed Vc of the preceding vehicle C by a predetermined value or more. Even in this case, the own vehicle O does not accelerate following the preceding vehicle P (see FIG. 8B).

  After that, when the preceding vehicle P approaches the preceding vehicle C ahead of the vehicle and suddenly decelerates (see FIG. 8C), the own vehicle O does not need to decelerate rapidly as described above. Thus, even with the configuration of the second modification, the host vehicle O is provided with the speed limit (Vo_max) as shown in FIG. 9, and therefore, the same effect as that of the above-described embodiment can be achieved.

  In addition, vehicle information such as the vehicle speed, position, and traveling direction of another vehicle equipped with the driving support system 100 including the wireless communication device 7 that performs road-to-vehicle communication with the roadside base station 200 is communicated via the roadside base station 200. It is good also as a structure (modification 3) which performs the process similar to the above-mentioned acceleration limitation related process using the acquired vehicle information. The detection of the vehicle speed, position, and traveling direction of the other vehicle is performed in the same manner as described above in the driving support system 100 of the other vehicle. In the third modification, the roadside base station 200 transmits and receives information through wireless communication with the wireless communication device 7 included in the driving support system 100.

  In the third modification, vehicle information transmitted from the roadside base station 200 is received by the wireless communication device 7 and output to the vehicle control ECU 10. The vehicle information transmitted from the roadside base station 200 is information on the speed, position, and traveling direction of the other vehicle received by the roadside base station 200 from the wireless communication device 7 of the other vehicle. The vehicle control ECU 10 acquires vehicle information input from the wireless communication device 7 of the host vehicle, and performs a preceding vehicle forward vehicle determination process. The wireless communication device 7 of the own vehicle corresponds to the first wireless communication device of the claims, and the wireless communication device 7 of the other vehicle corresponds to the second wireless communication device of the claims.

  In the preceding vehicle forward vehicle determination process of the modified example 3, it is determined whether or not the other vehicle equipped with the wireless communication device 7 that transmits the vehicle information acquired by the vehicle control ECU 10 to the roadside communication station is the preceding vehicle ahead vehicle. The determination is made in the same manner as described in the second modification. Then, according to the determination result, the same process as the acceleration restriction related process is performed.

  Here, the effect in the modification 3 is demonstrated using FIG.9 and FIG.10. FIG. 10 is a schematic diagram for explaining the relative positional relationship and traveling state of the host vehicle O, the preceding vehicle P, and the preceding vehicle forward vehicle C in the preceding vehicle follow-up control of the third modification. In the preceding vehicle follow-up control of the third modified example, the own vehicle O is described as controlling the preceding vehicle P so as to follow the target at a constant inter-vehicle distance and the same speed within a range not exceeding the set vehicle speed Vm. I do.

  Modification 3 has the same configuration as that of Modification 2 in that vehicle information of a preceding vehicle ahead is acquired by road-to-vehicle communication. Therefore, from the state of FIG. 10 (A) where the preceding vehicle forward vehicle C is caught in a traffic jam and stopped, the preceding vehicle P accelerates beyond the speed Vc of the preceding vehicle preceding vehicle C beyond a predetermined value. Even in this case, the own vehicle O does not accelerate following the preceding vehicle P (see FIG. 10B).

  Thereafter, when the preceding vehicle P approaches the preceding vehicle C ahead of the vehicle and suddenly decelerates (see FIG. 10C), the host vehicle O need not decelerate rapidly as described above. Thus, even with the configuration of the modification 3, the host vehicle O is provided with the speed limit (Vo_max) as shown in FIG.

  Further, the vehicle control ECU 10 may be configured to change the above-described brake start threshold (friction brake start threshold, engine brake start threshold) in accordance with the road surface condition (hereinafter, road surface condition). For example, the road surface condition includes μ of the road surface. Here, a case where the brake start threshold value is made variable according to two road surface conditions of high μ and low μ will be described as an example.

  First, as for two road surface conditions of high μ and low μ, an occupant such as a driver selects high μ or low μ and inputs it to the operation SW 9, for example. And when vehicle control ECU10 acquires the input result which selected high (micro | micron | mu) from operation SW9, it judges that the road surface condition is high (micro | micron | mu). On the other hand, when the vehicle control ECU 10 obtains the input result of selecting low μ from the operation SW 9, it is determined that the road surface condition is low μ. Therefore, the vehicle control ECU 10 corresponds to input result acquisition means and road surface condition determination means in the claims. The operation SW 9 corresponds to the input device in the claims.

  The road surface condition may be determined by another method. For example, using spectral characteristics that moisture has a large absorbance in the near-infrared wavelength band and that reflection of light in the near-infrared wavelength band varies depending on road conditions, using images captured by an infrared camera May be. In addition, it may be determined using the luminance of the visible light image, or may be determined using a temperature distribution image by thermography.

  When the vehicle control ECU 10 determines that the road surface condition is high μ, the vehicle control ECU 10 uses the above-described value as an offset value of the friction brake start threshold value formula or the engine brake start threshold value formula. On the other hand, if the road surface condition is determined to be low μ, What is necessary is just to set it as the structure changed into the value smaller than the above-mentioned value ((DELTA) c1, (DELTA) c2) as an offset value of a brake start threshold value type | formula or an engine brake start threshold value type | formula. According to this, when the road surface condition is judged to be high μ, the brake start threshold is set to a higher value than when judged to be low μ, while when judged to be low μ, it is judged high μ. The brake start threshold value is set to a lower value than the case. Therefore, vehicle control ECU10 is equivalent to the brake start threshold value change means of a claim.

  When it is determined that the road surface condition is high μ, the offset value of the friction brake start threshold value expression or the engine brake start threshold value expression is changed to a value larger than the above-described values (Δc1, Δc2), while the road surface condition is low μ. If it is determined, the offset value of the friction brake start threshold value formula or the engine brake start threshold value formula may be changed to a value smaller than the aforementioned values (Δc1, Δc2). In this case, the offset value of the friction brake start threshold value formula or the engine brake start threshold value formula may be set to the above-described values (Δc1, Δc2) in a default state where no selection input is made to the operation SW9.

  Furthermore, although it was set as the structure which judges two steps, high μ and low μ, here as a road surface condition, it is not necessarily restricted to this. For example, it is good also as a structure which judges three or more steps. In that case, the offset value may be changed lower as μ becomes lower.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

1 VSC_ECU, 2 rudder angle sensor, 3 G sensor, 4 yaw rate sensor, 5 ENG_ECU, 6 navigation ECU, 7 wireless communication device (first wireless communication device, second wireless communication device), 8 radar, 9 operation SW (input device) ) 10 vehicle control ECU (preceding vehicle following traveling device, inter-vehicle distance detecting means, relative speed determining means, preceding vehicle speed determining means, other vehicle information acquiring means, preceding vehicle forward vehicle determining means, preceding vehicle position determining means, current position Acquisition means, map data acquisition means, speed determination means, own vehicle speed detection means, road surface condition determination means, brake start threshold value change means, input result acquisition means, storage means, current value calculation means, threshold value calculation means, speed control means, progress Direction determination means), 61 position direction detector, 62 map data input device, 100 driving support system, 200 roadside base station, 300 roadside sensor

Claims (13)

This is a preceding vehicle follow-up traveling device that carries out preceding vehicle follow-up control that acquires information via a wireless communication device that is mounted on a vehicle and receives information through inter-vehicle communication and that allows the vehicle to follow the preceding vehicle. And
Own vehicle speed detecting means for detecting the speed of the own vehicle;
Other vehicle information acquisition means for sequentially acquiring the current position information and speed information of the other vehicle sequentially transmitted from other vehicles by inter-vehicle communication via the wireless communication device;
Preceding vehicle position determining means for determining a current position of the preceding vehicle;
Preceding vehicle speed determining means for determining the speed of the preceding vehicle;
Map data acquisition means for acquiring map data including at least road information;
From the current position of the preceding vehicle determined by the preceding vehicle position determining means, the current position information of other vehicles other than the preceding vehicle acquired by the other vehicle information acquiring means, and the map data acquired by the map data acquiring means, Preceding vehicle forward vehicle determination means for determining whether or not the other vehicle is a preceding vehicle forward vehicle positioned in the forward direction of the preceding vehicle on the same road as the preceding vehicle;
When the preceding vehicle forward vehicle determining means determines that the vehicle is ahead of the preceding vehicle, the speed information of the preceding vehicle determined by the preceding vehicle speed determining means and the speed information of the preceding vehicle ahead acquired by the other vehicle information acquiring means. Speed determining means for determining whether the speed of the vehicle ahead of the preceding vehicle is smaller than the speed of the preceding vehicle by a predetermined value or more based on
When the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is equal to or lower than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, the preceding vehicle A preceding vehicle following traveling device that suppresses acceleration by interrupting vehicle following control and maintaining the speed of the host vehicle. This is a preceding vehicle follow-up traveling device that carries out preceding vehicle follow-up control that acquires information via a wireless communication device that is mounted on a vehicle and receives information through road-to-vehicle communication, and that makes the vehicle follow the preceding vehicle. And
Own vehicle speed detecting means for detecting the speed of the own vehicle;
In addition to sequentially acquiring speed information of the preceding vehicle ahead located in a predetermined distance ahead of the preceding vehicle in the traveling direction on the same road as the preceding vehicle sequentially transmitted by road-to-vehicle communication via the wireless communication device Vehicle information acquisition means;
Preceding vehicle position determining means for determining a current position of the preceding vehicle;
Preceding vehicle speed determining means for determining the speed of the preceding vehicle;
Based on the speed of the preceding vehicle determined by the preceding vehicle speed determining unit and the speed information of the preceding vehicle preceding vehicle acquired by the other vehicle information acquiring unit, the speed of the preceding vehicle ahead is determined as the speed of the preceding vehicle. Speed determining means for determining whether or not a predetermined value is smaller than
When the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is equal to or lower than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, the preceding vehicle A preceding vehicle following traveling device that suppresses acceleration by interrupting vehicle following control and maintaining the speed of the host vehicle. This is a preceding vehicle follow-up traveling device that carries out preceding vehicle follow-up control that acquires information via a wireless communication device that is mounted on a vehicle and receives information through road-to-vehicle communication, and that makes the vehicle follow the preceding vehicle. And
Own vehicle speed detecting means for detecting the speed of the own vehicle;
The speed information, position information, and traveling direction information of the road vehicle detected by the road side sensor that detects the speed, position, and traveling direction of the road vehicle that is a vehicle on the road are acquired from the road side sensor and transmitted by road-to-vehicle communication. Other vehicle information acquisition means for sequentially acquiring, via the wireless communication device, speed information, position information, and traveling direction information of the on-road vehicle that is sequentially transmitted by road-to-vehicle communication from the roadside base station.
Preceding vehicle position determining means for determining a current position of the preceding vehicle;
A traveling direction determining means for determining a traveling direction of the preceding vehicle;
Preceding vehicle speed determining means for determining the speed of the preceding vehicle;
The current position of the preceding vehicle determined by the preceding vehicle position determining means and the traveling direction of the preceding vehicle determined by the traveling direction determining means, and the position information and traveling direction information of the road vehicle acquired by the other vehicle information acquiring means A preceding vehicle forward vehicle determining means for determining whether the road vehicle is a preceding vehicle preceding vehicle located within a predetermined distance ahead of the preceding vehicle in the traveling direction;
The speed of the preceding vehicle determined by the preceding vehicle speed determining means and the speed of the preceding preceding vehicle acquired by the other vehicle information acquiring means when the preceding vehicle preceding vehicle determining means determines that the preceding vehicle is ahead of the preceding vehicle. Based on the information, provided with a speed determination means for determining whether the speed of the preceding vehicle ahead is smaller than the speed of the preceding vehicle by a predetermined value or more,
When the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is equal to or lower than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, the preceding vehicle A preceding vehicle following traveling device that suppresses acceleration by interrupting vehicle following control and maintaining the speed of the host vehicle. A preceding vehicle follow-up travel device that acquires information via a first wireless communication device that is mounted on a vehicle and receives information by road-to-vehicle communication and that performs follow-up vehicle follow-up control that causes the vehicle to follow the preceding vehicle. Because
Own vehicle speed detecting means for detecting the speed of the own vehicle;
A roadside that receives speed information, position information, and traveling direction information of the road vehicle transmitted from a second wireless communication device mounted on a road vehicle that is a vehicle on a road other than the vehicle, and transmits the information by road-to-vehicle communication. Other vehicle information acquisition means for sequentially acquiring, via the wireless communication device, speed information, position information, and traveling direction information of the road vehicle sequentially transmitted from the base station by road-to-vehicle communication;
Preceding vehicle position determining means for determining a current position of the preceding vehicle;
A traveling direction determining means for determining a traveling direction of the preceding vehicle;
Preceding vehicle speed determining means for determining the speed of the preceding vehicle;
From the current position of the preceding vehicle determined by the preceding vehicle position determining means and the traveling direction of the preceding vehicle determined by the traveling direction determining means, and the position information of the road vehicle acquired by the other vehicle information acquiring means, Preceding vehicle forward vehicle determination means for determining whether or not the road vehicle is a preceding vehicle forward vehicle located within a predetermined distance ahead of the preceding vehicle in the traveling direction;
The speed of the preceding vehicle determined by the preceding vehicle speed determining means and the speed of the preceding preceding vehicle acquired by the other vehicle information acquiring means when the preceding vehicle preceding vehicle determining means determines that the preceding vehicle is ahead of the preceding vehicle. Based on the information, provided with a speed determination means for determining whether the speed of the preceding vehicle ahead is smaller than the speed of the preceding vehicle by a predetermined value or more,
When the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is equal to or lower than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, the preceding vehicle A preceding vehicle following traveling device that suppresses acceleration by interrupting vehicle following control and maintaining the speed of the host vehicle. In any one of Claims 1-4,
If the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is greater than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, While continuing the vehicle following control,
The preceding vehicle follow-up travel device is characterized in that the preceding vehicle follow-up control is continued even when a negative determination is made by the speed determining means. In any one of Claims 1-5,
After interrupting the preceding vehicle following control,
When the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is equal to or lower than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, the preceding vehicle While the vehicle tracking control continues to be interrupted,
If the speed determination means makes an affirmative determination and the speed of the host vehicle detected by the host vehicle speed detection means is greater than the speed of the preceding vehicle determined by the preceding vehicle speed determination means, While resuming car following control,
The preceding vehicle follow-up traveling device restarts the preceding vehicle follow-up control even when a negative determination is made by the speed determining means. In any one of Claims 1-6,
This is an index that represents the approaching / separating state with respect to the preceding vehicle in consideration of the speed of the preceding vehicle, and increases as the relative speed approaching the preceding vehicle increases, and increases as the inter-vehicle distance from the preceding vehicle decreases. In addition, an indicator that the gradient of increase with respect to a change in which the inter-vehicle distance becomes shorter becomes steeper as the inter-vehicle distance becomes shorter is used as a corrected approach / separation state evaluation index,
The preceding vehicle follow-up control is performed using the corrected approaching / separating state evaluation index,
An inter-vehicle distance detecting means for detecting an inter-vehicle distance between the preceding vehicle and the own vehicle;
A relative speed determining means for determining a relative speed of the own vehicle with respect to the preceding vehicle;
Brake offset value for lowering the corrected approaching / separating state evaluation index for the same inter-vehicle distance in a brake discriminant that is a formula showing the relationship between the corrected approaching / separating state evaluation index and the intervehicular distance at the time of starting the brake operation of the driver And a brake start threshold value equation indicating a relationship between the corrected approach / separation state evaluation index and the inter-vehicle distance at the time of the start of brake control, and the brake discriminant equation are more identical than the brake offset value. Completion of acceleration control indicating a relationship between the corrected approach / separation state evaluation index and the inter-vehicle distance at the time of termination of acceleration control, which is an expression obtained by adding an acceleration offset value that further reduces the correction approach / separation state evaluation index with respect to the inter-vehicle distance Storage means for storing a threshold expression;
A current value calculating means for sequentially calculating a current value of the corrected approaching / separating state evaluation index;
Threshold calculation means for calculating a brake start threshold value from the brake start threshold value formula and the current value of the inter-vehicle distance, and calculating an acceleration control end threshold value from the acceleration control end threshold value formula and the current value of the inter-vehicle distance;
The current value of the corrected approaching / separating state evaluation index calculated by the current value calculating unit is compared with the brake start threshold value and the acceleration control ending threshold value calculated by the threshold value calculating unit, and the current value of the corrected approaching / separating state evaluation index is If it is higher than the start threshold value, the brake is operated. If the current value of the corrected approach / separation state evaluation index is lower than the acceleration control end threshold value, acceleration control is performed, and the current value of the corrected approach / separation state evaluation index is the brake start threshold value and acceleration control. A preceding vehicle follow-up travel device, comprising: speed control means for causing the host vehicle to travel at a constant speed if it is between the end threshold values. In claim 7,
The storage means is a formula indicating a relationship between the corrected approach / separation state evaluation index and the inter-vehicle distance at the time of starting the operation of the friction brake, as a brake start threshold formula, and for the same inter-vehicle distance in the brake discriminant formula Friction brake start threshold value formula to which the first brake offset value for lowering the corrected approach / separation state evaluation index is added, and an expression showing the relationship between the corrected approach / separation state evaluation index and the inter-vehicle distance at the start of operation of the motor brake And a motor brake start threshold value formula obtained by adding a second brake offset value for further reducing the corrected approaching / separating state evaluation index for the same inter-vehicle distance from the first brake offset value to the brake discriminant. Is remembered,
The threshold value calculation means calculates a friction brake start threshold value from the friction brake start threshold value formula and the current value of the inter-vehicle distance, calculates a prime mover brake start threshold value from the prime mover brake start threshold value formula and the current value of the inter-vehicle distance, Calculate the acceleration control end threshold value from the acceleration control end threshold value formula and the current value of the inter-vehicle distance,
The speed control means compares the current value of the corrected approach / separation state evaluation index calculated by the current value calculation means with the friction brake start threshold, the motor brake start threshold, and the acceleration control end threshold calculated by the threshold calculation means. If the current value of the corrected approach / separation state evaluation index is higher than the friction brake start threshold value, the friction brake is activated, and if the current value of the corrected approach / separation state evaluation index is between the friction brake start threshold value and the prime mover brake start threshold value, When the prime mover brake is activated and the current value of the corrected approach / separation state evaluation index is lower than the acceleration control end threshold value, acceleration control is performed, and the current value of the corrected approach / separation state evaluation index is between the brake start threshold value and the acceleration control end threshold value. If this is the case, a preceding vehicle follow-up travel device that causes the host vehicle to travel at a constant speed. In claim 7 or 8,
Road surface condition judging means for judging the road surface condition;
A preceding vehicle follow-up travel device, further comprising: a brake start threshold value changing unit that makes the brake start threshold value variable according to the road surface condition determined by the road surface condition determining unit. In claim 9,
It further comprises input result acquisition means for acquiring an input result of an input device in which the occupant of the vehicle selects and inputs whether the road surface condition is high μ or low μ,
The road surface condition determination means determines whether the road surface condition is high μ or low μ according to the input result acquired by the input result acquisition means,
The brake start threshold value changing means sets the brake start threshold value to a higher value when the road surface condition determining means determines that the road surface condition is high μ than when it is determined that the road surface condition is low μ. When the road surface condition determining means determines that the road surface condition is low μ, the brake start threshold value is set to a lower value than when the road surface condition is determined to be high μ. Traveling device. In any one of Claims 7-10,
It further comprises current position acquisition means for sequentially acquiring the current position of the own vehicle,
The preceding vehicle position determining means includes
A preceding vehicle that determines a current position of the preceding vehicle from position information of the own vehicle acquired by the current position acquiring unit and an inter-vehicle distance between the preceding vehicle and the own vehicle detected by the inter-vehicle distance detecting unit. Follow-up traveling device. A preceding vehicle following traveling device according to claim 3 mounted on a vehicle;
A wireless communication device mounted on the vehicle;
A roadside sensor that is installed outside the vehicle and detects the speed, position, and traveling direction of a road vehicle that is a vehicle on the road;
A driving support system comprising: a roadside base station that acquires speed information, position information, and traveling direction information of a road vehicle detected by a roadside sensor from the roadside sensor and transmits the information by road-to-vehicle communication. A preceding vehicle following traveling device according to claim 4 mounted on a vehicle;
A first wireless communication device mounted on the vehicle;
A second wireless communication device mounted on a road vehicle that is a vehicle on a road other than the vehicle, and transmits speed information, position information, and traveling direction information of the road vehicle;
The speed information, position information, and traveling direction information of the road vehicle transmitted from the second wireless communication device of the road vehicle are received, and the received speed information, position information, and traveling direction information of the road vehicle are received between the road and the vehicle. A driving support system comprising a roadside base station that transmits by communication.

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