JP2007076472A - Operation support device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a driver to use the operation support device of a vehicle with a natural feeling under smooth control by continuously reflecting the traveling status of a preceding vehicle on its own vehicle. <P>SOLUTION: In automatic follow-up control in a traveling control unit 5, the region map of the self-vehicle target deceleration arithmetic formula of preceding vehicle deceleration-preceding speed constituted of preliminarily set two regions is referred to, and the self-vehicle target deceleration arithmetic formula of the region to which the deceleration and speed of the current preceding vehicle are belonging is selected, and the self-vehicle target deceleration is calculated by the selected self-vehicle target deceleration arithmetic formula, and automatic brake control(including follow-up stop control) or automatic acceleration control(including follow-up start control) or the like is performed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle driving support device that performs automatic tracking control on a preceding vehicle ahead of the host vehicle detected by a stereo camera, a monocular camera, a millimeter wave radar, or the like.

  In recent years, an on-board camera or the like detects the driving environment ahead, detects the preceding vehicle from the driving environment data, and follows the driving control for the preceding vehicle and the driving control for maintaining the distance between the preceding vehicle and the like above a certain level. Equipment has been developed and put into practical use.

For example, in Japanese Patent Application Laid-Open No. 2002-127781, the inter-vehicle time, which is the time difference until the host vehicle reaches the current position of the preceding vehicle, is calculated based on the inter-vehicle distance and the own vehicle speed. A technique for controlling an electronic throttle and a brake actuator to maintain time (a constant value) is disclosed. At this time, if the magnitude of the deceleration of the preceding vehicle exceeds the first specified value, a predetermined correction value is added to the target inter-vehicle time as the corrected inter-vehicle time, and acceleration / deceleration is performed using this corrected inter-vehicle time as a target. Control.
JP 2002-127781 A

  However, in the technique of correcting and controlling the target inter-vehicle time as in Patent Document 1 described above, the host vehicle is also affected by the driving of the preceding vehicle. For example, after the preceding vehicle suddenly decelerates, the vehicle gradually decelerates. If it performs, the own vehicle will also be controlled similarly. For this reason, although it is originally preferable to moderately decelerate while maintaining an appropriate inter-vehicle distance with the preceding vehicle, the operation of the vehicle at the portion switched by this correction is not smoothly performed and becomes discontinuous, There is a problem that an unnatural feeling is generated.

  The present invention has been made in view of the above circumstances, and it is intended to provide a driving support device for a vehicle that continuously reflects the traveling state of a preceding vehicle on the host vehicle and can be used by a driver with a natural sense through smooth control. Objective.

  The present invention includes a host vehicle traveling information detecting unit that detects traveling information of the host vehicle, a preceding vehicle information detecting unit that recognizes a preceding vehicle and detects preceding vehicle information, and a plurality of preset arithmetic expressions. The calculation formula for calculating the target deceleration of the host vehicle is selected from among the detected driving conditions of the preceding vehicle, and the driving information of the host vehicle and the preceding vehicle information are substituted into the selected calculation formula. Target deceleration calculation means for calculating the target deceleration, and acceleration / deceleration control means for controlling acceleration / deceleration based on the target deceleration, wherein the plurality of calculation formulas represent the vehicle speed of the current preceding vehicle. It is set for each area formed according to the deceleration and has a hysteresis characteristic in each of the case where the current area is shifted to the different area and the case where the different area is shifted to the current area. It is said.

  The vehicle driving support device according to the present invention continuously reflects the traveling state of the preceding vehicle on the host vehicle, and the driver can use it with a natural feeling through smooth control.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 6 show an embodiment of the present invention, FIG. 1 is a schematic configuration diagram of a driving support device mounted on a vehicle, FIG. 2 is a flowchart of an automatic tracking control program, and FIG. FIG. 4 is an explanatory diagram of an area map of the vehicle target deceleration calculation formula of the vehicle speed, FIG. 4 is an explanatory diagram of an area map of the preceding vehicle deceleration-preceding vehicle speed deceleration calculation formula of an example different from FIG. FIG. 6 is an explanatory diagram of an area map of a target vehicle deceleration calculation formula of preceding vehicle deceleration-preceding vehicle speed in an example different from FIGS. 3 and 4, and FIG. 6 is an explanatory diagram of parameters used in the formula.

  In FIG. 1, reference numeral 1 denotes a vehicle such as an automobile (own vehicle). The vehicle 1 is equipped with a cruise control system (ACC (Adaptive Cruise Control) system) 2 as an example of a vehicle driving support device. .

  The ACC system 2 mainly includes a stereo camera 3, a stereo image recognition device 4, a travel control unit 5, and the like. In the ACC system 2, basically, a constant speed travel control state in which no preceding vehicle exists. In this case, the vehicle travels while maintaining the vehicle speed set by the driver. When there is a preceding vehicle, the vehicle is controlled by an automatic follow-up control program shown in FIG.

  As will be described in detail later, this automatic tracking control program refers to an area map of a target vehicle deceleration calculation formula of preceding vehicle deceleration af−preceding vehicle speed Vf, which is composed of two preset areas, and The target vehicle deceleration calculation formula in the region to which the deceleration af and the speed Vf belong is selected, the target vehicle deceleration a is calculated using the selected target vehicle deceleration calculation formula, and automatic brake control (follow-up stop control) is performed. And automatic acceleration control (including follow-up start control) and the like. The automatic follow-up control program is executed by the traveling control unit 5, and therefore the traveling control unit 5 is configured to have functions as target deceleration calculation means and acceleration / deceleration control means.

  The stereo camera 3 is composed of a pair of (left and right) CCD cameras using a solid-state image pickup device such as a charge coupled device (CCD) as a stereo optical system. Are attached at regular intervals, and an object outside the vehicle is imaged in stereo from different viewpoints and output to the stereo image recognition device 4.

  In addition, the host vehicle 1 is provided with a vehicle speed sensor 6 that detects the host vehicle speed V0 as a host vehicle travel information detection unit. The host vehicle speed V0 is transmitted to the stereo image recognition device 4 and the travel control unit 5. Is output. Furthermore, the brake pedal ON / OFF signal from the brake switch 7 of the host vehicle 1 is input to the travel control unit 5.

  The stereo image recognition device 4 receives the image from the stereo camera 3 and the vehicle speed V0 from the vehicle speed sensor 6 and detects the front information of the three-dimensional object data and the white line data ahead of the vehicle 1 based on the image from the stereo camera 3. Then, the traveling path of the host vehicle 1 (the host vehicle traveling path) is estimated. Then, the preceding vehicle ahead of the host vehicle 1 is extracted, the preceding vehicle distance (inter-vehicle distance) L, the preceding vehicle speed ((change amount of the inter-vehicle distance L) + (own vehicle speed V0)) Vf, the preceding vehicle deceleration (preceding vehicle speed). Each data such as the differential value of Vf) af, the position of a stationary object other than the preceding vehicle, the white line coordinates, the white line recognition distance, and the own vehicle traveling path coordinates is output to the travel control unit 5.

  Here, the processing of the image from the stereo camera 3 in the stereo image recognition device 4 is performed as follows, for example. First, distance information is generated on the basis of the principle of triangulation from a pair of stereo image pairs captured in the traveling direction environment of the host vehicle 1 captured by the CCD camera of the stereo camera 3 from the corresponding positional deviation amount. And based on this distance information, compared with well-known grouping processing and pre-stored three-dimensional road shape data, solid object data, etc., white line data, guardrails, curbs, etc. existing along the road Side wall data and three-dimensional object data such as vehicles are extracted. In the three-dimensional object data, a distance to the three-dimensional object and a temporal change (relative speed with respect to the own vehicle 1) of this distance are obtained. In particular, in the closest vehicle on the own vehicle traveling path, in the substantially same direction as the own vehicle 1. A vehicle traveling at a predetermined speed (for example, 0 km / h or more) is extracted as a preceding vehicle. Of the preceding vehicles, a vehicle having a speed Vf of approximately 0 km / h is recognized as a stopped preceding vehicle. Thus, the stereo camera 3 and the stereo image recognition device 4 are provided as preceding vehicle information detection means.

  The traveling control unit 5 realizes a constant speed traveling control function for performing constant speed traveling control so as to maintain a traveling speed set by a driver's operation input, and an automatic tracking control function shown in FIG. Thus, there are a constant speed travel switch 8, a stereo image recognition device 4, a vehicle speed sensor 6, a brake switch 7 and the like composed of a plurality of switches connected to a constant speed travel operation lever provided on the side of the steering column. It is connected.

  The constant speed travel switch 8 is a vehicle speed set switch for setting the target vehicle speed during constant speed travel, a coast switch for mainly changing the target vehicle speed to the lower side, a resume switch for changing the target vehicle speed to the upper side, etc. It is configured. Further, a main switch (not shown) for turning ON / OFF constant speed traveling control and automatic tracking control is disposed in the vicinity of the constant speed traveling operation lever.

  When the driver turns on a main switch (not shown) and sets a desired vehicle speed by means of a constant speed traveling operation lever, a signal from the constant speed traveling switch 8 is input to the traveling control unit 5. Then, the vehicle speed detected by the vehicle speed sensor 6 is output as a signal to the throttle valve control device 9 so that the vehicle speed detected by the driver converges to the set vehicle speed set by the driver, and the opening degree of the throttle valve 10 is feedback-controlled. The vehicle is automatically driven in a state, or a deceleration signal is output to the automatic brake control device 11 to activate the automatic brake.

  Further, when the traveling control unit 5 performs constant speed traveling control and recognizes a preceding vehicle by the stereo image recognition device 4, the traveling control unit 5 is automatically switched to automatic tracking control described later under a predetermined condition. . The constant speed traveling control function and the automatic tracking control function are used when the driver steps on the brake, when the vehicle speed V0 exceeds a preset upper limit value, or the main switch is turned off. If it is canceled, it is canceled.

  That is, as shown in FIG. 2, the automatic tracking control program in the traveling control unit 5 first reads the necessary parameters in step (hereinafter abbreviated as “S”) 101, proceeds to S102, and selects the arithmetic expression selection flag Fa. Refer to This arithmetic expression selection flag Fa is set to “1” when a first arithmetic expression described later is selected last time according to the traveling state (deceleration af, vehicle speed Vf) of the preceding vehicle, and is set to a second described later. This flag is set when “2” is selected.

  Here, in the present embodiment, the area map of the target vehicle deceleration calculation formula of preceding vehicle deceleration af−preceding vehicle speed Vf consisting of two regions set in advance, and the calculation formulas (first operation) set in the respective regions. 1 and 2) will be described.

  For example, as shown in FIG. 3A, the region of the own vehicle target deceleration calculation formula of preceding vehicle deceleration af−preceding vehicle speed Vf is Vf = Vf = 1.0 · af is defined as the boundary line Tth, and the upper region (the region where the vehicle speed Vf of the preceding vehicle is high but the deceleration af is small) is set as the first region for selecting the first arithmetic expression. The region (region where the vehicle speed Vf of the preceding vehicle is low but the deceleration af is high) is set in advance as a second region for selecting the second arithmetic expression.

The first arithmetic expression is an arithmetic expression for following the vehicle while maintaining the distance between the vehicles set in advance with respect to the preceding vehicle on the assumption that the preceding vehicle continues to travel. 6 and the preceding vehicle are in the relationship shown in FIG. 6, that is, the current vehicle speed V0, the own vehicle deceleration a0, the preceding vehicle speed Vf, the preceding vehicle deceleration af, and the inter-vehicle distance L after t seconds. When the host vehicle 1 moves forward by a distance Ls, the preceding vehicle moves forward by a distance Lf to the preceding vehicle predicted position, and the inter-vehicle distance from the host vehicle 1 becomes a target inter-vehicle distance Dtgt (a distance set by a map or calculation), (1) Formula is materialized.
L + Lf = Ls + Dtgt (1)
here,
Lf = Vf · t− (1/2) · af · t ² (2)
Ls = V0 · t− (1/2) · a0 · t ² (3)
Therefore, substituting these equations (2) and (3) into the above equation (1), deleting t and solving for a0, and assuming that this a0 is the target deceleration a of the host vehicle 1, Equation (4) is obtained.
a = af + ((V0−Vf) ² / (L−Dtgt)) (4)
Therefore, this equation (4) is defined as the first arithmetic expression in the first region.

Similarly, the second arithmetic expression is an arithmetic expression for the vehicle 1 to follow and stop the preceding vehicle at a preset inter-vehicle distance on the assumption that the preceding vehicle stops. As shown in FIG. In other words, the current vehicle speed V0, the own vehicle deceleration a0, the preceding vehicle speed Vf, the preceding vehicle deceleration af, and the inter-vehicle distance L, the host vehicle 1 moves forward by the distance Ls after t seconds, and the preceding vehicle Is assumed to travel forward by a distance Lf to the predicted position of the preceding vehicle, and the distance between the vehicle 1 and the host vehicle 1 becomes the target stop distance Dstop (constant value: 5 m, for example), and the following equation (5) is established.
L + Lf = Ls + Dstop (5)
here,
Lf = Vf ² / (2 · af) (6)
Ls = V0 ² / (2 · a0) (7)
Therefore, substituting these equations (6) and (7) into the above equation (5), solving for a0, and setting this a0 as the target deceleration a of the host vehicle 1, the following equation (8) Get.

a = (af · V0 ² ) / (Vf ² + 2 · af · (L−Dstop)) (8)
Therefore, this equation (8) is defined as the second arithmetic expression in the second region. Note that all the decelerations described above have a positive sign in the deceleration direction.

  In addition, the area map of the target vehicle deceleration calculation formula of preceding vehicle deceleration af−preceding vehicle speed Vf, which is composed of two preset areas, is not limited to the example of FIG. 3A, and FIG. ), Or an area map as shown in FIG. 5A.

  That is, in the region map of FIG. 4A, until the preceding vehicle speed Vf becomes Vfc1 (for example, a low speed of 35 km / h or less), the boundary line Tth11 of Vf = Vfc1 is set, and the region exceeding that is Vf = 1. A boundary line Tth12 of 0 · af is used. Then, above the boundary lines Tth11 and Tth12 is defined as a first area, the first arithmetic expression is set as an area, and the lower area is set as a second area, and the second arithmetic expression is set as an area. It is.

  Further, in the area map of FIG. 5A, until the preceding vehicle speed Vf becomes Vfc1 (for example, a low speed of 35 km / h or less), the boundary line Tth21 of Vf = Vfc1 is used, and Vfc1 <Vf ≦ Vfc2 (for example, 60 km / h). ), The boundary line Tth22 of Vf = 1.0 · af is set in the medium / low speed range, and the boundary line Tth23 of Vf = 1.3 · af is set in the medium / high speed range of Vfc2 <Vf ≦ Vfc3 (for example, 100 km / h). In the high-speed region of <Vf, the boundary line Tth24 of Vf = 1.5 · af is used. Then, above the boundary lines Tth21, Tth22, Tth23, Tth24 is defined as a first area, a first arithmetic expression is set as an area, and a lower area is defined as a second area, and a second arithmetic expression is set. It is determined as an area. In addition to these, the boundary line may be expressed by a curve or the like.

  As a result of the determination in S102 of the flowchart of FIG. 2, if the arithmetic expression selection flag Fa is “1” and the first arithmetic expression has been selected last time, the process proceeds to S103, and the first area is changed to the first area. In order to provide a hysteresis characteristic when transitioning to the region 2, correction is set by moving the boundary Tth downward by S1 so as to widen the first region. For example, the correction is performed as shown in FIG. 3 (a), FIG. 4 (a), or FIG. 5 (a).

  On the other hand, as a result of the determination in S102, if the arithmetic expression selection flag Fa is “2” and the second arithmetic expression has been selected last time, the process proceeds to S104, and the first area is selected from the second area. In order to give a hysteresis characteristic when transitioning to a region, the boundary Tth is moved upward by S2 so as to widen the second region, and correction is set. For example, the correction is performed as shown in FIG. 3B, FIG. 4B, or FIG. 5B. Here, the width for providing the hysteresis is S1> S2, and the transition from the first arithmetic expression to the second arithmetic expression is more effective than the transition from the second arithmetic expression to the first arithmetic expression. It is set to difficult characteristics.

  After performing region correction in consideration of hysteresis in S103 or S104, the process proceeds to S105 to determine whether or not the current traveling state of the preceding vehicle (preceding vehicle deceleration af−preceding vehicle speed Vf) is within the first region. To do.

  As a result of the determination in S105, if the current traveling state of the preceding vehicle (preceding vehicle deceleration af−preceding vehicle speed Vf) is within the first region, the process proceeds to S106, and the first arithmetic expression (the above-mentioned (4) The own vehicle target deceleration a is calculated from the equation (1), the process proceeds to S107, the calculation formula selection flag Fa is set to "1", the process proceeds to S108, and the throttle valve control device 9 is operated based on the target deceleration a calculated in S106. Alternatively, an instruction signal is output to the automatic brake control device 11 to perform acceleration / deceleration control, and the program is exited.

  Further, if the result of the determination in S105 is that the current traveling state of the preceding vehicle (preceding vehicle deceleration af−preceding vehicle speed Vf) is within the second region, the process proceeds to S109 and the second arithmetic expression ((8 )), The vehicle target deceleration a is calculated, the process proceeds to S110, the calculation formula selection flag Fa is set to "2", the process proceeds to S108, and the throttle valve control device based on the target deceleration a calculated in S109. 9 or output an instruction signal to the automatic brake control device 11 to perform acceleration / deceleration control and exit the program.

  As described above, according to the embodiment of the present invention, the following traveling control is performed by switching the equation for following traveling according to the traveling state of the preceding vehicle. Smooth control allows the driver to use it with a natural feeling. In addition, since the boundary line is set in consideration of hysteresis, the control can be performed stably without hunting.

  In this embodiment, the preceding vehicle is recognized on the basis of the image from the stereo camera. However, other technologies, for example, recognition based on information from the millimeter wave radar and the monocular camera are performed. It may be.

Schematic configuration diagram of a driving support device mounted on a vehicle Flow chart of automatic tracking control program Explanation of the area map of the target vehicle deceleration calculation formula for the preceding vehicle deceleration-preceding vehicle speed Explanatory drawing of the area | region map of the own vehicle target deceleration calculating formula of the preceding vehicle deceleration-preceding vehicle speed of the example different from FIG. Explanatory drawing of the area | region map of the own vehicle target deceleration calculating formula of the preceding vehicle deceleration-preceding vehicle speed of the example different from FIG. Explanatory diagram of parameters used in mathematical formula

Explanation of symbols

1 Vehicle 2 ACC system (driving support device)
3 Stereo camera (preceding vehicle information detection means)
4 Stereo image recognition device (preceding vehicle information detection means)
5 Travel control unit (target deceleration calculation means, acceleration / deceleration control means)
6 Vehicle speed sensor (own vehicle travel information detection means)
9 Throttle valve control device 10 Throttle valve 11 Automatic brake control device

Claims (2)

Own vehicle running information detecting means for detecting running information of the own vehicle;
A preceding vehicle information detecting means for recognizing a preceding vehicle and detecting preceding vehicle information;
An arithmetic expression for calculating a target deceleration of the host vehicle is selected from a plurality of preset arithmetic expressions in accordance with the detected traveling state of the preceding vehicle, and the host vehicle is selected as the selected arithmetic expression. Target deceleration calculation means for calculating the target deceleration by substituting the traveling information of the vehicle and the preceding vehicle information,
Acceleration / deceleration control means for performing acceleration / deceleration control based on the target deceleration,
The plurality of arithmetic expressions are set for each region formed in accordance with the current vehicle speed and deceleration of the preceding vehicle, and the transition from the current region to a different region and the transition from the different region to the current region. A driving support apparatus for a vehicle, characterized in that each has a hysteresis characteristic. The plurality of calculation formulas are: a first calculation for setting a first inter-vehicle distance that is set in advance by the host vehicle to the preceding vehicle on the assumption that the preceding vehicle continues to travel, in the first region for following the vehicle. And a second calculation formula that is set in a second region for following and stopping the preceding vehicle at an inter-vehicle distance that the host vehicle sets in advance on the assumption that the preceding vehicle stops.
The hysteresis characteristic is given to each of the case of shifting from the first region to the second region and the case of shifting from the second region to the first region. Vehicle driving support device.

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