JP2014108758A - Travel control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a travel control device capable of reducing time required for recognition of a forward vehicle from a following vehicle.SOLUTION: A travel control device comprises: a vehicle detection part 11 which detects a following vehicle C0 of an own-vehicle C2; and a travel control part 12 which performs travel control for the own-vehicle C2 at a setting speed, and changes a speed of the own-vehicle if the following vehicle C0 is detected by the vehicle detection part 11 during the travel control.

Description

  The present invention relates to a traveling control device that controls traveling of a vehicle.

  2. Description of the Related Art Conventionally, a tracking target vehicle specifying device as described in, for example, Japanese Patent Application Laid-Open No. 2011-221653 is known in relation to a travel control device. This tracking target vehicle specifying device specifies a tracking target vehicle based on speed information together with position information of surrounding vehicles. The tracking target vehicle based on the speed information is identified by comparing the speed of the surrounding vehicle acquired by the inter-vehicle communication and the speed of the preceding vehicle acquired by the radar sensor using the speed component in the traveling direction of the host vehicle.

JP 2011-221653 A

  However, in such a tracking target vehicle specifying device, when a plurality of surrounding vehicles, for example, a plurality of surrounding vehicles during auto-cruise traveling, are traveling at substantially the same speed, the tracking target vehicle is recognized based on the speed information. May take time.

  Therefore, the present invention seeks to provide a travel control device that can shorten the time required for the preceding vehicle to recognize the preceding vehicle.

  The travel control device according to the present invention includes a vehicle detection unit that detects a succeeding vehicle of the host vehicle and a travel control of the host vehicle at a set speed, and when the succeeding vehicle is detected by the vehicle detection unit during the travel control. And a travel control unit that varies the speed of the host vehicle.

  According to the traveling control device of the present invention, when a succeeding vehicle is detected during traveling control of the host vehicle at a set speed, the speed of the host vehicle is changed. Thereby, recognition of the front vehicle by the following vehicle is promoted. Therefore, the time required for the recognition of the preceding vehicle by the following vehicle can be shortened.

  ADVANTAGE OF THE INVENTION According to this invention, the travel control apparatus which can shorten the time required for the recognition of the front vehicle by a succeeding vehicle can be provided.

It is a block diagram which shows the traveling control apparatus which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of a traveling control apparatus. It is a figure which shows an example of the traveling control which does not involve the fluctuation | variation of speed. It is a figure which shows an example of the traveling control accompanied with the fluctuation | variation of speed. It is a figure which shows the speed change of the surrounding vehicle in the case shown in FIG. It is a figure which shows the speed change of the surrounding vehicle in the case shown in FIG.

  Hereinafter, a travel control device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  First, with reference to FIG. 1, the structure of the traveling control apparatus which concerns on embodiment of this invention is demonstrated. FIG. 1 is a block diagram showing a travel control apparatus according to an embodiment of the present invention.

  The travel control device is a device having a function of controlling the host vehicle at a set speed and reducing the time required for the subsequent vehicle to recognize the preceding vehicle. The travel control device is mounted on the host vehicle, and as shown in FIG. 1, is configured around an electronic control unit 10 (hereinafter referred to as ECU 10).

  The ECU 10 is connected to a vehicle sensor 21 that detects travel information of the host vehicle. As the vehicle sensor 21, for example, a GPS sensor, a wheel speed sensor, an acceleration sensor, a gyro sensor, or the like is used.

  The ECU 10 is connected to a surrounding sensor 22 that detects the surrounding situation of the host vehicle. As the peripheral sensor 22, for example, a millimeter wave radar sensor, a laser radar sensor, an ultrasonic sensor, a stereo camera, a video camera, or the like is used.

  The ECU 10 is connected to a communication device 23 for transmitting / receiving traveling information to / from surrounding vehicles. In particular, the communication device 23 receives travel information of surrounding vehicles by inter-vehicle communication or road-to-vehicle communication. The travel information of the surrounding vehicles includes, for example, vehicle ID, position information, speed information, and detection information of the preceding vehicle by the surrounding vehicles. In addition, the detection information of a front vehicle is information which shows whether the surrounding vehicle detected the front vehicle, for example, a tracking object vehicle, with a periphery sensor.

  A control execution unit 24 that executes travel control is connected to the ECU 10. As the control execution unit 24, a drive system or a brake system actuator is used. The control execution unit 24 controls the drive system and the braking system based on a control command from the ECU 10. Note that the control execution unit 24 may further control the steering system based on a control command from the ECU 10.

  The ECU 10 includes a vehicle detection unit 11 and a travel control unit 12. ECU10 is comprised mainly by CPU, ROM, and RAM, and implement | achieves the function of the vehicle detection part 11 and the traveling control part 12 through execution of the program by CPU. The functions of the vehicle detection unit 11 and the travel control unit 12 may be realized by two or more ECUs.

  The vehicle detection unit 11 detects a subsequent vehicle of the host vehicle. The vehicle detection unit 11 detects the following vehicle using travel information of surrounding vehicles. In addition, the vehicle detection part 11 may detect a following vehicle using the detection result of the surrounding sensor 22 which detects the back condition of the own vehicle with the driving information of a surrounding vehicle.

  The vehicle detection unit 11 determines whether or not there is a surrounding vehicle within a predetermined range behind the host vehicle based on the positional information of the surrounding vehicle and the host vehicle, that is, the positional relationship between the two. In addition, the vehicle detection unit 11 determines the elapsed time since the surrounding vehicle detected the preceding vehicle based on the detection information of the preceding vehicle by the surrounding vehicle, that is, information indicating whether or not the surrounding vehicle detected the preceding vehicle. It is determined whether it is within a predetermined time. Accordingly, the vehicle detection unit 11 sets a surrounding vehicle, for example, the own vehicle, that is present in a predetermined range behind the own vehicle and that has elapsed time after the detection of the preceding vehicle within a predetermined time as the tracking target vehicle. A surrounding vehicle is detected as a vehicle following the host vehicle.

  The traveling control unit 12 controls traveling of the host vehicle at a set speed. That is, the travel control unit 12 recognizes and determines the travel path and the vehicle ahead based on the detection result of the peripheral sensor 22 and sends a control command for traveling at the set speed to the control execution unit 24. The traveling control unit 12 sends out a control command for controlling the actuators of the driving system and the braking system particularly in accordance with the set speed. The traveling control at the set speed includes traveling control that follows the preceding vehicle.

  Here, the traveling control unit 12 varies the speed of the host vehicle when the vehicle detecting unit 11 detects a succeeding vehicle while the host vehicle is traveling at the set speed. For example, the traveling control unit 12 changes the control gain used for setting the control amounts of the drive system and the braking system so that the speed of the host vehicle fluctuates slightly more than during the traveling control at the set speed. The control gain is changed, for example, by making the control gain smaller than during traveling control at a set speed, or by increasing or decreasing it with a long cycle.

  Next, the operation of the travel control apparatus according to the embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a flowchart showing the operation of the travel control device. The traveling control device, particularly the ECU 10, repeatedly executes the processing shown in FIG. 2 for each set period while the vehicle is traveling at a set speed.

  As shown in FIG. 2, the vehicle detection unit 11 determines whether there is a surrounding vehicle (S11). The vehicle detection part 11 determines with the surrounding vehicle existing, when the communication apparatus 23 receives the driving information of a surrounding vehicle. If it is not determined that there is a surrounding vehicle, the process ends.

  When it is determined that there is a surrounding vehicle, the traveling control unit 12 determines whether or not the road surface gradient is gentle (S12). The traveling control unit 12 determines that the road surface gradient is gentle when the absolute value of the road surface gradient detected by the vehicle sensor 21 is less than the threshold value. This is to avoid a decrease in traveling stability due to, for example, speed fluctuation when the road surface gradient is steep. If it is not determined that there is a surrounding vehicle, the process ends.

  When it is determined that the road surface gradient is gentle, the vehicle detection unit 11 determines whether or not a surrounding vehicle exists within a predetermined range behind the host vehicle (S13). This determination is made based on the positional information of the surrounding vehicle and the host vehicle, that is, the positional relationship between the two. If it is not determined that the road surface gradient is gentle, the process ends.

  When it is determined that there is a surrounding vehicle within a predetermined range behind the host vehicle, the vehicle detection unit 11 determines whether the elapsed time since the surrounding vehicle has detected the preceding vehicle is within a predetermined time. (S14). This determination is performed based on detection information of the preceding vehicle, that is, information indicating whether or not the surrounding vehicle has detected the preceding vehicle. In addition, a process is complete | finished when it determines with a surrounding vehicle not existing in the predetermined range behind the own vehicle.

  Thus, the vehicle detection unit 11 determines the presence of the following vehicle roughly based on the positional information of the surrounding vehicle and the own vehicle, and then determines based on the information indicating whether the surrounding vehicle has recognized the preceding vehicle. By doing so, the subsequent vehicle of the own vehicle is recognized with high accuracy.

  When the following vehicle is detected, the traveling control unit 12 varies the speed of the host vehicle (S15). For example, the traveling control unit 12 changes the control gain used for setting the control amounts of the driving system and the braking system so that the speed of the own vehicle fluctuates a little larger than that during the traveling control of the own vehicle at the set speed. If no subsequent vehicle is detected, the process ends.

  FIG. 3 and FIG. 4 are diagrams showing an example of traveling control with and without speed fluctuation. 5 and 6 are diagrams showing changes in the speed of surrounding vehicles in the case shown in FIGS. 3 and 4, respectively.

  In the example shown in FIGS. 3 and 4, the following vehicle C0 travels behind the surrounding vehicles C1 and C2 with the surrounding vehicle C2 as the tracking target vehicle. The succeeding vehicle C0 receives the speeds Va1 and Va2 of the surrounding vehicles C1 and C2, and detects the speed Vb of the surrounding vehicle C2 by the surrounding sensor.

  Here, the following vehicle C0 tries to recognize the tracking target vehicle based on the speed information because the surrounding vehicles C1 and C2 are close to each other and it is difficult to recognize the tracking target vehicle based on the position information. That is, in the following vehicle C0, any of the surrounding vehicles C1 and C2 is a target vehicle based on the correlation coefficient between the time series data of the speeds Va1 and Va2 and the time series data of the speed Vb, the mean square error, and the like. Try to recognize.

  However, in the example shown in FIG. 3, the surrounding vehicles C1 and C2 are traveling at substantially the same set speed. For this reason, as shown in FIG. 5, the speeds Va1, Va2, and Vb show slight vertical fluctuations similar to each other on the basis of the set speed Vc in accordance with a predetermined control gain. For this reason, the following vehicle C0 requires time until the time-series data of the speeds Va1, Va2, and Vb is statistically processed to recognize the tracking target vehicle.

  On the other hand, in the example shown in FIG. 4, after the surrounding vehicle C2 detects the following vehicle C0, the speed of the own vehicle is changed by changing the control gain, for example. Therefore, as shown in FIG. 6, the speed Va1 shows a slight up-and-down fluctuation based on the cruise speed Vc according to a predetermined control gain, whereas the speeds Va2 and Vb follow the changed control gain. The fluctuation is slightly larger than that during the traveling control of the host vehicle at the set speed. For this reason, the following vehicle C0 can recognize the surrounding vehicle C2 as a tracking target vehicle by statistically processing the time series data of the speeds Va1, Va2, and Vb in a shorter time than the case shown in FIG.

  As described above, according to the travel control apparatus according to the embodiment of the present invention, when a succeeding vehicle is detected during travel control of the host vehicle at a set speed, the speed of the host vehicle is changed. Thereby, recognition of the front vehicle by the following vehicle is promoted. Therefore, the time required for the recognition of the preceding vehicle by the following vehicle can be shortened.

  In addition, embodiment mentioned above demonstrated best embodiment of the traveling control apparatus which concerns on this invention, and the traveling control apparatus which concerns on this invention is not limited to what was described in this embodiment. . The travel control device according to the present invention may be modified from the travel control device according to the present embodiment or applied to other devices without departing from the gist of the invention described in each claim.

  In the description of the embodiment, it is determined in S12 of FIG. 2 whether or not the speed of the host vehicle is changed according to the speed of the road surface gradient, but the speed of the host vehicle is set regardless of the speed of the road surface gradient. It may be varied.

  DESCRIPTION OF SYMBOLS 10 ... Electronic control unit (ECU), 11 ... Vehicle detection part, 12 ... Travel control part, 21 ... Vehicle sensor, 22 ... Peripheral sensor, 23 ... Communication apparatus, 24 ... Control execution part, C0 ... Subsequent vehicle, C1, C2 ... neighboring vehicles.

Claims (4)

A vehicle detection unit for detecting a succeeding vehicle of the host vehicle;
A travel control device comprising: a travel control unit configured to control the travel of the host vehicle at a set speed, and to change a speed of the host vehicle when the vehicle detection unit detects the succeeding vehicle during the travel control. .   The travel control device according to claim 1, wherein the travel control unit urges detection of a preceding vehicle by the following vehicle by changing a speed of the host vehicle.   The travel control device according to claim 1, wherein the travel control unit varies the speed of the host vehicle by changing a control gain for the travel control.   The travel control device according to any one of claims 1 to 3, wherein the vehicle detection unit detects the succeeding vehicle that uses the host vehicle as a tracking target vehicle.

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