JP2007269273A - Drive support equipment of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly suppress the acceleration/deceleration of a vehicle under the consideration of not only the current vehicle behavior but also a vehicle behavior anticipated from now on, and to achieve comfortable control without generating any sense of incompatibility in following up a preceding vehicle. <P>SOLUTION: In executing the follow-up acceleration/deceleration control of follow-up traveling control, a calculated target acceleration/deceleration (a) is limited by a limit value Lm to be set according to a target yaw rate γt (high speed time) necessary for its own vehicle 1 to follow up a preceding vehicle based on its own vehicle speed V0 and the relative location of the preceding vehicle to its own vehicle 1 or a limit value Lm to be set according to a target steering angle St (low speed time) necessary for it own vehicle 1 to follow up a preceding vehicle based on the relative location of the preceding vehicle to its own vehicle 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a driving support apparatus for a vehicle that performs acceleration / deceleration control following a preceding vehicle.

  2. Description of the Related Art In recent years, in vehicles, various vehicle driving support devices that recognize a preceding vehicle using a front recognition device using a camera, a laser radar, and the like and follow the recognized preceding vehicle have been developed and put into practical use.

For example, in Japanese Laid-Open Patent Publication No. 2000-355231, in a preceding vehicle follow-up control device that matches the vehicle speed with a target vehicle speed calculated based on the inter-vehicle distance and the vehicle speed, the vehicle speed is calculated from the lateral acceleration detected by the lateral acceleration sensor. A lateral acceleration correction value is calculated by subtracting an offset amount that is a large value when in the low vehicle speed region and a small value when in the high vehicle speed region. Based on this lateral acceleration correction value, a vehicle speed subtraction value that is small when it is small and large when it is large is calculated, and the target vehicle speed is suppressed based on this vehicle speed subtraction value. A technique is disclosed that eliminates the uncomfortable feeling given to the driver by optimally performing the deceleration control.
JP 2000-355231 A

  However, in the technology for suppressing the target vehicle speed disclosed in Patent Document 1 described above, since the target vehicle speed is suppressed based on the current vehicle behavior, acceleration / deceleration after the actual vehicle behavior occurs is suppressed. However, there is a problem that a delay occurs with respect to the actual feeling and the vehicle behavior deviates from the movement of the preceding vehicle to follow, and the driver has an unnatural feeling.

  The present invention has been made in view of the above circumstances. In consideration of not only the current vehicle behavior but also the vehicle behavior expected in the future, the vehicle acceleration / deceleration is appropriately suppressed, and smooth and uncomfortable when following the preceding vehicle. An object of the present invention is to provide a vehicle driving support device that can perform comfortable control.

  The present invention includes a host vehicle travel information detection unit that detects travel information of the host vehicle, a preceding vehicle information detection unit that recognizes a preceding vehicle and detects the preceding vehicle information, the traveling information of the host vehicle, and the preceding vehicle. Based on the information, the target acceleration / deceleration calculating means for calculating the target acceleration / deceleration necessary for the host vehicle to follow the preceding vehicle, and the host vehicle based on the host vehicle travel information and the preceding vehicle information. A target parameter for estimating a target parameter necessary for the vehicle to follow the preceding vehicle, calculating a limit value for limiting the target acceleration / deceleration according to the target parameter, and limiting the target acceleration / deceleration by the limit value And an acceleration / deceleration limiting means.

  According to the vehicle driving support device of the present invention, the acceleration / deceleration of the vehicle is appropriately suppressed in consideration of not only the current vehicle behavior but also the predicted vehicle behavior in the future, and smooth and uncomfortable when following the preceding vehicle. Comfortable control is possible.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 8 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 a follow-up acceleration / deceleration control program, and FIG. 3 is a target acceleration / deceleration a calculation process. 4 is a flowchart of a target acceleration / deceleration a restriction processing routine, FIG. 5 is an explanatory diagram of an area map of a target vehicle acceleration / deceleration-preceding vehicle speed target acceleration / deceleration equation, and FIG. 6 is used in a target acceleration / deceleration equation. 7 is an explanatory diagram showing the relationship between the coordinate positions of the host vehicle and the preceding vehicle, and FIG. 8 is an explanatory diagram showing an example of the limit value.

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

  The ACC system 2 mainly includes a stereo camera 3, a stereo image recognition device 4, a control unit 5, and the like. In the ACC system 2, basically, the vehicle travels while maintaining the vehicle speed set by the driver in the constant speed traveling control state in which no preceding vehicle exists, and the following acceleration / deceleration control in the case where the preceding vehicle exists. The automatic tracking control of the tracking steering control is executed.

  Further, the host vehicle 1 is provided with a vehicle speed sensor 6 that detects the host vehicle speed V0, a handle angle sensor 7 that detects the handle angle θH, and a yaw rate sensor 8 that detects the yaw rate γr. The vehicle speed V 0 is input to the stereo image recognition device 4 and the control unit 5, and the steering wheel angle θH and the yaw rate γr are input to the control unit 5. Further, an ON-OFF signal of a brake pedal from a brake switch (not shown) is input to the control unit 5.

  In addition, signals from various switches from a constant speed travel switch 9 constituted by a plurality of switches connected to a constant speed travel operation lever provided on the side of the steering column or the like are input to the control unit 5. The constant speed travel switch 9 is a vehicle speed set switch that sets a target vehicle speed during constant speed travel, a coast switch that mainly changes and sets the target vehicle speed to the lower side, a resume switch that mainly changes and sets the target vehicle speed to the higher side, etc. It consists of 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.

  The stereo camera 3 is composed of a set of (left and right) CCD cameras using a solid-state imaging device such as a charge coupled device (CCD) as a stereo optical system. These left and right CCD cameras are each mounted at a certain interval in front of the ceiling in the vehicle interior, take a stereo image of an object outside the vehicle from different viewpoints, and output image data to the stereo image recognition device 4.

  The stereo image recognition device 4 receives the image data from the stereo camera 3 and the own vehicle speed V0 from the vehicle speed sensor 6, and based on the image data from the stereo camera 3, the front information of the three-dimensional object data and the white line data in front of the own vehicle 1. Is detected, and the traveling path of the own vehicle 1 (own vehicle traveling path) is estimated. Then, the preceding vehicle ahead of the host vehicle 1 is extracted, and the preceding vehicle position (for example, the coordinate position on the XZ coordinate system with the host vehicle 1 as the origin as shown in FIG. 7), the preceding vehicle distance (inter-vehicle distance). Distance) L, preceding vehicle speed ((change in inter-vehicle distance L) + (own vehicle speed V0)) Vf, preceding vehicle acceleration / deceleration (differential value of preceding vehicle speed Vf) af, position of stationary object other than preceding vehicle, white line coordinates, white line Each data such as the recognition distance and the own vehicle traveling path coordinates is output to the control unit 5.

  Here, the processing of the image data from the stereo camera 3 in the stereo image recognition device 4 is performed as follows, for example. First, for a pair of stereo images of the environment in the traveling direction of the host vehicle 1 captured by the CCD camera of the stereo camera 3, processing for obtaining distance information over the entire image from the corresponding positional deviation amount by the principle of triangulation. To generate a distance image representing a three-dimensional distance distribution. And based on this data, 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, the distance to the three-dimensional object and the temporal change (relative speed with respect to the own vehicle 1) of this distance are obtained. 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. Further, as the three-dimensional object information and the preceding vehicle information, the position information of the left end point and the right end point of the rear surface is stored, and the approximate center between the left end point and the right end point of the rear surface is the center of gravity position of the three-dimensional object or the preceding vehicle. Is remembered as Thus, the stereo camera 3 and the stereo image recognition device 4 have a function as a preceding vehicle information detection means.

  The control unit 5 includes a function of constant speed traveling control for performing constant speed traveling control so as to maintain a traveling speed set by a driver's operation input, and automatic tracking control (tracking acceleration / deceleration control and tracking steering control). When the driver turns on a main switch (not shown) and sets a desired vehicle speed with a constant speed operation lever, a signal from the constant speed travel switch 9 is input to the control unit 5. Then, a signal is output to the throttle valve control device 10 so that the vehicle speed detected by the vehicle speed sensor 6 converges to the set vehicle speed set by the driver, and the opening degree of the throttle valve 11 is feedback-controlled, so that the host vehicle 1 is automatically operated. The vehicle is run at a constant speed, or a deceleration signal is output to the automatic brake control device 12 to activate the automatic brake.

  When the stereo image recognition device 4 recognizes the preceding vehicle during the constant speed traveling control, the control unit 5 is automatically switched to automatic follow-up control described later. Note that the constant speed traveling control function and the automatic tracking control function are canceled when the driver steps on the brake or when the main switch is turned off.

  When the vehicle travel control shifts to the follow-up travel control, in the example of the follow-up acceleration / deceleration control of the present embodiment, the target vehicle acceleration / deceleration af−the preceding vehicle speed Vf composed of two preset areas will be described in detail later. Referring to the area map of the acceleration / deceleration calculation formula, select the target acceleration / deceleration calculation formula for the area to which the current acceleration / deceleration af and speed Vf belong, and calculate the target acceleration / deceleration a using the selected target acceleration / deceleration calculation formula To do. Further, the target acceleration / deceleration a is set according to the target yaw rate γt (at high speed) necessary for the own vehicle 1 to follow the preceding vehicle based on the own vehicle speed V0 and the relative position of the preceding vehicle with respect to the own vehicle 1. The limit value Lm or the limit value Lm set according to the target steering angle St (at low speed) necessary for the host vehicle 1 to follow the preceding vehicle based on the relative position of the preceding vehicle with respect to the host vehicle 1 is limited. A signal is output to the automatic brake control device 12 to perform automatic brake control (including follow-up stop control), or a signal is output to the throttle valve control device 10 to perform automatic acceleration control (including follow-up start control). As described above, in the present embodiment, the control unit 5 is configured to have functions as a target acceleration / deceleration calculating means and a target acceleration / deceleration limiting means.

  In addition, when the vehicle traveling control shifts to the tracking traveling control, the control unit 5 executes the vehicle speed V0 in an area where the vehicle speed V0 is, for example, less than 35 km / h in the example of the tracking steering control of the present embodiment. In the case of the vehicle speed region set in advance in the vehicle, the target yaw rate γt required for the own vehicle 1 to follow the preceding vehicle is calculated based on the own vehicle speed V0 and the relative position of the preceding vehicle with respect to the own vehicle 1. Based on this target yaw rate γt, the power steering command current value ic that follows the preceding vehicle is calculated and output to the electric power steering control device 13. On the other hand, in the vehicle speed region set in advance in the vehicle speed region, the target steering angle St required for the host vehicle 1 to follow the preceding vehicle based on the relative position of the preceding vehicle with respect to the host vehicle 1 is set. Based on this target steering angle St, the power steering command current value ic that follows the preceding vehicle is calculated and output to the electric power steering control device 13.

  Reference numeral 14 denotes a liquid crystal monitor that displays each operating state of the ACC system 2, and is shared with, for example, an in-vehicle navigation system.

  Next, follow-up acceleration / deceleration control of follow-up running control will be described with reference to the flowchart of FIG. This follow-up acceleration / deceleration control program is executed every predetermined time when the main switch of the ACC system 2 is turned on and shifts to follow-up running control in which a preceding vehicle is present. First, a step (hereinafter, “S”) is executed. (Abbreviated as) 101, necessary parameters are read. Next, the process proceeds to S102, where the target acceleration / deceleration a calculation process is executed, and the process proceeds to S103, where the target acceleration / deceleration a calculated in S102 is limited, and the process proceeds to S104, where it is limited as necessary in S103. The processed target acceleration / deceleration a is output to the automatic brake control device 12 or the throttle valve control device 10 to exit the program.

  Here, first, the calculation process of the target acceleration / deceleration a executed in S102 will be described with reference to the flowchart of FIG.

  First, in S201, the arithmetic expression selection flag Fa is referred to. This calculation formula selection flag Fa is set to “1” when the first calculation formula described later is selected last time according to the traveling state (acceleration / deceleration af, vehicle speed Vf) of the preceding vehicle, and is set to “2” described later. This flag is set when “2” is selected.

  Here, in the present embodiment, the area map of the target vehicle acceleration / deceleration formula of preceding vehicle acceleration / deceleration af−preceding vehicle speed Vf composed of two regions set in advance, and the calculation equation (first An arithmetic expression and a second arithmetic expression) will be described.

  The area of the target vehicle acceleration / deceleration af-preceding vehicle speed Vf target acceleration / deceleration equation is, for example, as shown in FIG. 5A, the absolute value | af | of the preceding vehicle and the absolute value | Vf of the preceding vehicle. |, Vf = 1.0 · af is the boundary line Tth, and the upper region (region where the absolute value | Vf | of the preceding vehicle is high but the absolute value | af | of the acceleration / deceleration is small) is the first region. The second region is set as the first region for selecting the arithmetic expression 1 and the lower region (region where the absolute value | Vf | of the preceding vehicle is low but the absolute value | af | of the acceleration / deceleration is high) is the second region. It is preset as a second area for selecting an expression. In this embodiment, the sign of acceleration / deceleration is positive in the deceleration direction and negative in the acceleration direction.

The first arithmetic expression is an arithmetic expression for following the vehicle while maintaining the inter-vehicle distance set in advance by the host vehicle 1 with respect to the preceding vehicle on the assumption that the preceding vehicle continues to travel. 1 and the preceding vehicle are in a relationship as shown in FIG. 6, that is, the current vehicle speed V0, the own vehicle acceleration / deceleration a0, the preceding vehicle speed Vf, the preceding vehicle acceleration / deceleration af, and the inter-vehicle distance L after t seconds. If 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), The target acceleration / deceleration a of the vehicle 1 is obtained from the following equation (1).
a = af + ((V0−Vf) ² / (L−Dtgt)) (1)
Therefore, the expression (1) 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 acceleration / deceleration a0, the preceding vehicle speed Vf, the preceding vehicle acceleration / 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 If the vehicle travels a distance Lf up 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), the following equation (2) is established.
L + Lf = Ls + Dstop (2)
here,
Lf = Vf ² / (2 · af) (3)
Ls = V0 ² / (2 · a0) (4)
Therefore, substituting these equations (3) and (4) into the above equation (2), solving for a0, and setting this a0 as the target acceleration / deceleration a of the host vehicle 1, the following equation (5) Get.

a = (af · V0 ² ) / (Vf ² + 2 · af · (L−Dstop)) (5)
Therefore, this equation (5) is defined as the second arithmetic expression in the second region. Note that the sign of the deceleration direction is positive for all the accelerations and decelerations described above.

  It should be noted that the area map of the target acceleration / deceleration equation of the preceding vehicle acceleration / deceleration af−preceding vehicle speed Vf composed of the above-described two areas is not limited to this, and may be divided by a plurality of boundaries. good.

  As a result of the determination in S201 of the flowchart of FIG. 3, if the arithmetic expression selection flag Fa is “1” and the first arithmetic expression has been selected last time, the process proceeds to S202, 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 made as shown in FIG.

  On the other hand, as a result of the determination in S201, if the arithmetic expression selection flag Fa is “2” and the second arithmetic expression has been selected last time, the process proceeds to S203, 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 made as shown in FIG. 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 S202 or S203, the process proceeds to S204 to determine whether or not the current traveling state of the preceding vehicle (preceding vehicle acceleration / deceleration af−preceding vehicle speed Vf) is within the first region. To do.

  As a result of the determination in S204, if the current traveling state of the preceding vehicle (preceding vehicle acceleration / deceleration af−preceding vehicle speed Vf) is within the first region, the process proceeds to S205 and the first arithmetic expression (the above-described (1) The target acceleration / deceleration a is calculated from the equation (1), the process proceeds to S206, the calculation equation selection flag Fa is set to "1", and the routine is exited.

  If the current traveling state of the preceding vehicle (preceding vehicle acceleration / deceleration af−preceding vehicle speed Vf) is within the second region as a result of the determination in S204, the process proceeds to S207, and the second arithmetic expression ((5 )), The target acceleration / deceleration a is calculated, the process proceeds to S208, the calculation expression selection flag Fa is set to "2", and the routine is exited.

  As described above, according to the embodiment of the present invention, the following traveling control (following acceleration / deceleration control) is performed by switching the expression for following traveling according to the traveling state of the preceding vehicle. It is performed continuously and the driver can use the driver with a natural feeling through smooth control. In addition, since the boundary line is set in consideration of hysteresis, the control can be performed stably without hunting.

  Next, the target acceleration / deceleration speed limiting process executed in S103 will be described with reference to the flowchart of FIG.

First, in S301, a predicted time (contact predicted time) TTC until the host vehicle 1 reaches the preceding vehicle is calculated by, for example, the following equation (6).
TTC = L / (V0−Vf) (6)

  Thereafter, the process proceeds to S302, in which it is determined whether or not the predicted contact time TTC calculated in S301 is shorter than a preset time TT1 (for example, 5 seconds), and when it is shorter than TT1 (when TTC <TT1), Prioritizing safety, the target acceleration / deceleration a is not limited, and the routine is exited as it is.

Conversely, when the predicted contact time TTC is equal to or longer than the preset time TT1 (when TTC ≧ TT1), the process proceeds to S303, and the current position of the host vehicle 1 and the preceding position are calculated by the following equation (7). A target travel radius Rt is calculated based on the position of the car. That is, in the coordinate system shown in FIG. 7 where the host vehicle 1 is the origin O, the coordinates of the center of gravity position of the preceding vehicle are (xt, zt).
Rt = (xt ² + zt ² ) / (2 · xt) (7)

  In S304, it is determined whether or not the control area setting flag F is “0”. The control area setting flag F is a flag that is set to “0” when the control is executed in the high speed area last time and is set to “1” when the control is executed in the low speed area. As will be described later, this is for setting the region variably with a hysteresis between the low speed region and the high speed region.

As a result of the determination in S304, if the control area setting flag F is set to “0”, that is, if the control was previously executed in the area on the high speed side, the process proceeds to S305, and the host vehicle speed V0 is V1 (for example, 20 km). / h) to determine whether it is higher. As a result of the determination in S305, if the host vehicle speed V0 is higher than V1, the process proceeds to S306 again to execute control in the high speed side region, and the target yaw rate γt is calculated by the following equation (8). To do.
γt = V0 / Rt (8)

After calculating the target yaw rate γt in S306, the process proceeds to S307, the limit value Lm is calculated based on the target yaw rate γt by the following equation (9), the process proceeds to S308, and the control region setting flag F is set to “0”. Is set, and the process proceeds to S309.
| Lm | = Lm2−K1 · | γt | (9)
Here, the reason why Lm is an absolute value is to apply this equation (9) in both the acceleration direction and the deceleration direction. K1 is a constant, and Lm2 is a constant (for example, 0.5 · g). When | Lm | calculated by equation (9) is | Lm |> Lm1 (for example, 0.3 · g), | Lm | is limited by Lm1 (| Lm | = Lm1). The characteristic of the limit value Lm is shown in FIG. In the present embodiment, the limit value Lm in the acceleration direction and the deceleration direction has the same characteristic, but may have different characteristics.

If the vehicle speed V0 is equal to or lower than V1 as a result of the determination in S305 described above, the process proceeds to S311 in order to shift to the control in the low speed region, and the target steering angle St is calculated by the following equation (10). Is calculated.
St = (Lw · Ns) / Rt (10)
Here, Lw is a wheel base, and Ns is a steering gear ratio.

After calculating the target steering angle St in S311, the process proceeds to S312 and the limit value Lm is calculated based on the target steering angle St according to the following equation (11). The process proceeds to S313, and the control region setting flag F is set to “ 1 ”is set, and the process proceeds to S309.
| Lm | = Lm4−K2 · | St | (11)
Here, the reason why Lm is an absolute value is to apply this equation (11) in both the acceleration direction and the deceleration direction. K2 is a constant, and Lm4 is a constant (for example, 0.5 · g). When | Lm | calculated by the expression (11) is | Lm |> Lm3 (for example, 0.3 · g), | Lm | is limited by Lm3 (| Lm | = Lm3). The characteristic of the limit value Lm is substantially the same as the characteristic of FIG. 8 described above by replacing the target yaw rate γt with the target steering angle St, Lm1 with Lm3, and Lm2 with Lm4. In the present embodiment, the limit value Lm in the acceleration direction and the deceleration direction has the same characteristic, but may have different characteristics.

  On the other hand, if “1” is set in the control area setting flag F as a result of the determination in S304 described above, that is, if control was previously executed in the low speed area, the process proceeds to S310, and the host vehicle speed V0 is V2. It is determined whether it is lower than (for example, 25 km / h). As a result of the determination in S310, if the host vehicle speed V0 is lower than V2, the process proceeds to S311 again to execute the control in the low speed region, and the target steering angle St is set by the above-described equation (10). Calculate.

  Thereafter, the process proceeds to S312, where the limit value Lm is calculated based on the target steering angle St by the above-described equation (11), the process proceeds to S313, "1" is set in the control region setting flag F, and the process proceeds to S309. move on.

  If the result of determination in S310 is that the host vehicle speed V0 is equal to or greater than V2, the process proceeds to S306 to shift to control in the high speed region, and the target yaw rate γt is set according to the above equation (8). Calculate.

  Thereafter, the process proceeds to S307, the limit value Lm is calculated based on the target yaw rate γt by the above-described equation (9), the process proceeds to S308, the control area setting flag F is set to “0”, and the process proceeds to S309. .

  When the process proceeds from S308 or S313 to S309, the target acceleration / deceleration a calculated in S102 is limited by the limit value Lm, that is, the absolute value | a | of the target acceleration / deceleration becomes equal to or greater than the absolute value | Lm | of the limit value. In this case, the absolute value | a | of the target acceleration / deceleration is limited as the absolute value | Lm | of the limit value, and the routine is exited.

  As described above, according to the present embodiment, in the follow-up acceleration / deceleration control of the follow-up running control, the subject vehicle 1 leads the calculated target acceleration / deceleration a based on the subject vehicle speed V0 and the relative position of the preceding vehicle with respect to the subject vehicle 1. Necessary for the vehicle 1 to follow the preceding vehicle based on the limit value Lm set according to the target yaw rate γt (at high speed) required to follow the vehicle or the relative position of the preceding vehicle with respect to the own vehicle 1 The limit is set by a limit value Lm set according to the target steering angle St (at low speed). Therefore, the acceleration / deceleration of the vehicle is appropriately suppressed in consideration of not only the current vehicle behavior but also the vehicle behavior expected in the future, so that smooth and comfortable control can be performed when following the preceding vehicle.

  Further, by properly using the limit value Lm set according to the target yaw rate γt and the limit value Lm set according to the target steering angle St, a region where the target yaw rate γt is small in the region where the vehicle speed V0 is low (equation (8)). Even in a region where V0 is close to 0, an appropriate limit value Lm is set according to the target steering angle St, so that it is possible to realize a natural sensory follow-up control.

  Further, the calculation of the limit value Lm in the present embodiment is performed by a simple linear function as shown in the equation (9) or (11), so that a complicated algorithm is not required and it can be set at high speed. Control with excellent response is possible.

  In this embodiment, since hysteresis is provided at the boundary of the vehicle speed region when selecting the limit value Lm set according to the target yaw rate γt and the limit value Lm set according to the target steering angle St, control is performed. Is not hunting and smooth transition is possible. This hysteresis setting may be omitted depending on the vehicle.

  In the present embodiment, the target acceleration / deceleration a is calculated by selecting an arithmetic expression from the area map of the target acceleration / deceleration calculation expression of preceding vehicle acceleration / deceleration af−preceding vehicle speed Vf consisting of two predetermined areas. However, it goes without saying that the present invention can be applied even if it is obtained by other methods. For example, the target inter-vehicle time is calculated and set based on the own vehicle speed V0, and the target acceleration / deceleration a is calculated based on the inter-vehicle distance L, the preceding vehicle speed Vf, the own vehicle speed V0, and the target inter-vehicle time. it can.

  Further, in the present embodiment, the target yaw rate required for the own vehicle 1 to follow the preceding vehicle based on the own vehicle speed V0 and the relative position of the preceding vehicle with respect to the own vehicle 1 in the high speed region according to the vehicle speed region. It is limited by a limit value Lm set according to γt, and is set according to the target steering angle St required for the own vehicle 1 to follow the preceding vehicle based on the relative position of the preceding vehicle with respect to the own vehicle 1 in the low speed region. However, depending on the vehicle, only the limit value calculated by either may be used.

  Further, in the present embodiment, the limit value Lm is calculated from the target yaw rate γt or the target steering angle St. However, the control may be similarly performed using other well-known parameters such as the target lateral acceleration. good.

  In the present embodiment, the preceding vehicle is recognized based on the image from the stereo camera. However, other technologies, for example, those that recognize based on information from the millimeter wave radar and the monocular camera are used. It may be.

Schematic configuration diagram of a driving support device mounted on a vehicle Flow chart of following acceleration / deceleration control program Flow chart of target acceleration / deceleration a calculation processing routine Flow chart of target acceleration / deceleration a limit processing routine Explanatory diagram of the area map of the target vehicle acceleration / deceleration formula for the preceding vehicle acceleration / deceleration-preceding vehicle speed Explanatory diagram of parameters used in the target acceleration / deceleration formula Explanatory diagram showing the relationship between the coordinate position of the host vehicle and the preceding vehicle Explanatory drawing showing an example of the limit value

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 Control unit (target acceleration / deceleration calculation means, target acceleration / deceleration limit means)
6 Vehicle speed sensor (own vehicle travel information detection means)
10 Throttle valve control device 11 Throttle valve 12 Automatic brake control device

Claims (3)

Own vehicle running information detecting means for detecting running information of the own vehicle;
A preceding vehicle information detecting means for recognizing the preceding vehicle and detecting the preceding vehicle information;
Target acceleration / deceleration calculating means for calculating a target acceleration / deceleration necessary for the host vehicle to follow the preceding vehicle based on the traveling information of the host vehicle and the preceding vehicle information;
Based on the travel information of the host vehicle and the preceding vehicle information, a target parameter necessary for the host vehicle to follow the preceding vehicle is estimated, and a limit value for limiting the target acceleration / deceleration according to the target parameter is set. A target acceleration / deceleration limiting means for calculating and limiting the target acceleration / deceleration by the limit value;
A vehicle driving support apparatus comprising:   2. The vehicle driving support apparatus according to claim 1, wherein the target parameter is either a target yaw rate or a target steering angle.   The target acceleration / deceleration limiting means does not limit the target acceleration / deceleration when the predicted time until the host vehicle reaches the preceding vehicle is shorter than a preset value. The driving support device for a vehicle according to claim 1 or 2.

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