JP2012187979A - Inter-vehicular distance control device and inter-vehicular distance control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inter-vehicular distance control device which can increase an inter-vehicular distance range where follow-up traveling can be controlled even if the initial value of a target inter-vehicular distance L is not set to a large value, and can control follow-up traveling while giving reduced discomfort to a driver.SOLUTION: When it is determined that an inter-vehicular distance Lrel between an own vehicle MM and a leading vehicle present in the traveling direction of the own vehicle MM is decreased to a preliminarily set control start distance or shorter, the control device starts follow-up traveling control and controls a braking/driving force of the own vehicle MM so that the inter-vehicular distance Lrel becomes a preliminarily set target inter-vehicular distance L. When a current accelerator opening is large with respect to a set initial value AP0 of an accelerator opening, the controller performs decrease correction to decrease the target inter-vehicular distance L, and when the current accelerator opening is small, the control device performs increase correction to increase the target inter-vehicular distance L.

Description

  The present invention relates to an inter-vehicle distance control technique for performing follow-up traveling with respect to a preceding vehicle.

  As an inter-vehicle distance control device, for example, there is a device described in Patent Document 1. In this device, when the inter-vehicle distance between the preceding vehicle and the host vehicle is equal to or less than the target inter-vehicle distance initial value, follow-up running control for the preceding vehicle is started. In this device, as the accelerator opening increase amount relative to the preceding vehicle follow-up control start time is larger, a value obtained by subtracting the target inter-vehicle distance initial value by a distance corresponding to the increase amount is used as the target inter-vehicle distance of the follow-up running control. Set.

JP-A-8-17000

In such a conventional inter-vehicle distance control device, when the inter-vehicle distance desired by the driver is shorter than the initial target inter-vehicle distance, the target inter-vehicle distance is shortened by depressing the accelerator pedal, and the driver It is possible to follow the vehicle with the following distance.
Here, in the above-mentioned inter-vehicle distance control device, when setting a large inter-vehicle distance range in which the follow-up traveling control is possible, it is necessary to set a large initial target inter-vehicle distance value. However, if the target inter-vehicle distance initial value is set to be large, if the inter-vehicle distance desired by the driver is short, the accelerator opening at the time when the inter-vehicle distance desired by the driver becomes too large will give the driver an uncomfortable feeling. There is a fear. On the other hand, if the target inter-vehicle distance initial value is set short, there is an increased possibility that the inter-vehicle distance desired by the driver is longer than the initial inter-vehicle distance value. There are cases where follow-up running control cannot be performed at a distance. Thus, in the above-mentioned inter-vehicle distance control device, it is difficult to set the initial target inter-vehicle distance initial value to an appropriate value, so it is difficult to perform follow-up running control with a low sense of discomfort for the driver.
The present invention has been made paying attention to the above points, and can increase the inter-vehicle distance range in which the follow-up driving control can be performed without setting the initial value of the target inter-vehicle distance to a large value. The purpose is to enable follow-up running control with a low sense of incongruity.

In order to solve the above problems, the present invention starts follow-up running control when it is determined that the inter-vehicle distance between the preceding vehicle and the own vehicle existing in the traveling direction of the own vehicle is equal to or less than a preset control start distance, The braking / driving force of the host vehicle is controlled so that the inter-vehicle distance becomes a preset target inter-vehicle distance. Then, the accelerator opening detected by the accelerator opening detecting means at the time when the follow-up running control is started is set as the accelerator opening initial value, and the current accelerator opening is set with respect to the set accelerator opening initial value. When it is large, the target inter-vehicle distance is corrected to decrease, and when the current accelerator opening is small, the target inter-vehicle distance is corrected to increase.
Note that the control start distance and the initial value of the target inter-vehicle distance may be the same distance.

  According to the present invention, the target inter-vehicle distance is decreased or increased in accordance with the accelerator opening increase or opening decrease from the set accelerator opening initial value. For this reason, even if the initial value of the target inter-vehicle distance is not set large, the inter-vehicle distance range in which the follow-up control can be performed can be increased, and the follow-up running control with a low sense of incongruity for the driver can be achieved.

It is a schematic diagram of the device composition concerning the embodiment based on the present invention. It is a figure which shows the example of the functional block of the inter-vehicle distance control apparatus which concerns on embodiment based on this invention. It is a figure which shows the control block which concerns on embodiment based on this invention. It is a flowchart which shows an example of the process sequence of an accelerator opening initial value setting part. It is a flowchart which shows an example of the process sequence of a target inter-vehicle distance setting part. It is an example of the map which calculates gain GainL. It is an example of the map which calculates gain GainV. It is an example of the map which shows the relationship between variation | change_quantity (DELTA) L of target inter-vehicle distance, and (DELTA) AP. It is a flowchart which shows an example of the process sequence of an inter-vehicle distance servo part. It is a flowchart which shows an example of the process sequence of an end process part. It is a figure which shows an example of the timing chart at the time of follow-up driving control. It is a figure which shows an example of the timing chart at the time of completion | finish of control.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a host vehicle MM equipped with an inter-vehicle distance control device of the present embodiment.
That is, the host vehicle MM includes a wheel speed sensor 7, a preceding vehicle information detection sensor 3, an accelerator opening sensor 2, a throttle opening sensor 8, a brake controller 6, and a throttle opening control unit that controls driving force. 5 and. In the present embodiment, the braking / driving force of the host vehicle MM can be controlled by the brake controller 6 and the throttle opening degree control unit 5. Reference numeral 9 denotes an engine as a drive source for driving the host vehicle MM. Reference numerals 1FL, 1FR, 1RL, and 1RR denote wheels.
The wheel speed sensor 7 is provided corresponding to each wheel of the host vehicle MM, detects the wheel speed of each wheel, and outputs it to the inter-vehicle distance controller 4.

  The preceding vehicle information detection sensor 3 detects a preceding vehicle located in front of the host vehicle MM, which is the traveling direction of the host vehicle MM, and outputs information on the detected preceding vehicle to the inter-vehicle controller 4. For example, the preceding vehicle information detection sensor 3 emits laser light in front of the host vehicle MM and receives reflected light, detects the time from the emission of the laser light to reception of the reflected light, and outputs the detected time to the inter-vehicle distance controller 4. Consists of radar sensors. As the radar sensor, a known radar sensor such as a laser radar system or a millimeter wave radar system may be appropriately selected and used. In the present embodiment, the preceding vehicle information detection sensor 3 is described as a radar sensor of a laser radar type, but may be a millimeter wave radar type. Moreover, a camera etc. may be sufficient. Any information can be used as long as it can detect information on an object in front of the vehicle traveling direction. Information on the preceding vehicle includes an inter-vehicle distance Lrel with the preceding vehicle and a relative speed ΔV of the preceding vehicle. The relative speed ΔV may be calculated from the inter-vehicle distance Lrel with the preceding vehicle, or may be detected from the frequency change of the reflected wave with respect to the outgoing wave.

The accelerator opening sensor 2 detects an accelerator opening AP, which is an opening (operation amount) of an accelerator pedal operated by the driver, and outputs the detected accelerator opening AP to the inter-vehicle controller 4.
The throttle opening sensor 8 detects the throttle opening of the engine 9 and outputs the detected throttle opening to the inter-vehicle controller 4 and the throttle opening controller 5.

  The throttle opening control unit 5 calculates the target throttle opening based on the target engine torque input from the inter-vehicle controller 4 and the accelerator opening AP detected by the accelerator opening sensor 2, and calculates the calculated target throttle opening. Based on the above, the throttle opening of the engine 9 is electronically controlled. For the target throttle opening, for example, a map that defines the correlation between the target engine torque or the accelerator opening AP and the target throttle opening is stored in advance, and the input target engine torque or the detected accelerator opening AP is stored in the map. Based on the map drawing, the target throttle opening may be calculated. Further, for example, the correlation between the target engine torque or accelerator opening AP and the target throttle opening is stored in advance as a mathematical formula, and based on the input target engine torque or the detected accelerator opening AP and the pre-stored mathematical formula. Then, the target throttle opening may be calculated. The calculation method of the target throttle opening can be changed as appropriate.

The brake controller 6 controls the braking force generated by the wheels 1FL, 1FR, 1RL, and 1RR so that the target braking force of each wheel input from the inter-vehicle distance controller 4 is obtained.
Here, the host vehicle MM includes a braking device. The brake device will be described. The brake pedal 11 operated by the driver is connected to the master cylinder 12 via a booster (not shown). The master cylinder 12 is connected to each wheel cylinder 13 of each wheel via a fluid pressure circuit 14. As a result, when the brake control is not activated, the brake fluid pressure is increased by the master cylinder 12 in accordance with the amount of depression of the brake pedal 11 by the driver. The increased braking fluid pressure is supplied to each wheel cylinder 13 of each wheel through a fluid pressure circuit 14. The braking fluid pressure control unit 15 controls the actuator in the fluid pressure circuit based on the braking force command value output from the brake controller 6 to individually control the braking fluid pressure to each wheel.

As the brake fluid pressure controller 15 and the fluid pressure circuit 14, for example, a brake fluid pressure controller used in anti-skid control (ABS), traction control (TCS), or vehicle dynamics control device (VDC) may be used. .
The inter-vehicle controller 4 includes an inter-vehicle distance Lrel and a relative speed detected by the preceding vehicle information detection sensor 3, a wheel speed of each wheel detected by the wheel speed sensor 7, and an accelerator pedal detected by the accelerator opening sensor 2. The accelerator opening value and the current engine throttle opening controlled by the throttle opening control unit 5 detected by the throttle opening sensor 8 are acquired. Then, the inter-vehicle controller 4 calculates a target inter-vehicle distance L for follow-up travel based on these acquired values, and makes the target engine torque and the inter-vehicle distance Lrel coincide with the target inter-vehicle distance L and the inter-vehicle distance Lrel. The target throttle opening is output to the throttle opening control unit 5 and the target brake force is output to the brake controller 6.

The inter-vehicle controller 4 includes an accelerator opening initial value setting unit 4A, a target inter-vehicle distance unit 4B, and an inter-vehicle distance control unit 4C as in the functional block shown in FIG.
The accelerator opening initial value setting means 4A sets the accelerator opening initial value AP0. The accelerator opening initial value setting means 4A of the present embodiment sets the accelerator pedal opening to the accelerator opening initial value AP0 based on the detection of the accelerator opening sensor 2 when the follow-up running control is started. In addition, when the accelerator opening initial value setting unit 4A of the present embodiment determines that the inter-vehicle distance Lrel with the preceding vehicle detected by the preceding vehicle information detection sensor 3 coincides with the target inter-vehicle distance L, the accelerator opening initial value setting means 4A The accelerator opening AP at that time is reset to the accelerator opening initial value AP0. The accelerator opening initial value AP0 may be a fixed value or a value obtained by multiplying the accelerator opening AP at the start of the follow-up traveling control by a predetermined gain.

  When the target inter-vehicle distance means 4B determines that the follow-up traveling control is started, the target inter-vehicle distance means 4B obtains and sets the target inter-vehicle distance L. Further, the target inter-vehicle distance means 4B is based on the accelerator opening initial value AP0 set by the accelerator opening initial value setting means 4A and the accelerator opening detected by the accelerator opening sensor 2, and the set target inter-vehicle distance L described above. Correct. Specifically, when the accelerator opening is larger than the accelerator opening initial value AP0, the target inter-vehicle distance L is corrected to decrease, and when the accelerator opening is smaller than the accelerator opening initial value AP0, the target inter-vehicle distance is corrected. The distance L is corrected to increase.

  When the inter-vehicle distance control means 4C determines that the current inter-vehicle distance Lrel is equal to or less than the preset control start distance Ls, the preceding vehicle information detection sensor 3 detects the preceding vehicle as the following traveling control. The braking / driving force of the host vehicle MM is controlled such that the inter-vehicle distance Lrel is equal to the target inter-vehicle distance L for following traveling. Specifically, the braking / driving force of the host vehicle MM is controlled through the throttle opening control unit 5 and the brake controller 6 so that the inter-vehicle distance Lrel becomes the target inter-vehicle distance L. Further, when the inter-vehicle distance control means 4C determines that the inter-vehicle distance Lrel with the preceding vehicle detected by the preceding vehicle information detection sensor 3 is larger than the control end distance for ending the following traveling, the following traveling is ended. The end process control is executed.

Next, an example of the inter-vehicle distance control executed by the inter-vehicle controller 4 will be described with reference to FIG. 3 which is a control block diagram.
As shown in FIG. 3, the inter-vehicle controller 4 includes an accelerator opening initial value setting unit 41, a target inter-vehicle distance setting unit 42, an inter-vehicle distance servo unit 43, and an end processing unit 44.
The accelerator opening initial value setting unit 41 is based on the inter-vehicle distance Lrel, which is a relative distance from the preceding vehicle based on the detection of the preceding vehicle information detection sensor 3, and the accelerator opening AP of the accelerator pedal detected by the accelerator opening sensor 2. The accelerator opening initial value AP0 and the follow-up control flag Ffw are set.

The processing of the accelerator opening initial value setting unit 41 will be described with reference to the flowchart of FIG.
In step S10, the inter-vehicle distance Lrel from the preceding vehicle based on the detection of the preceding vehicle information detection sensor 3, the accelerator pedal opening AP of the accelerator pedal detected by the accelerator opening sensor 2, and the target set by the target inter-vehicle distance setting unit 42 The previous value Lz of the inter-vehicle distance L is read. The previous value Lz of the target inter-vehicle distance L corresponds to the current target inter-vehicle distance L.
Next, in step S20, it is determined whether follow-up running control is started. When the follow-up running control is started, the process proceeds to step S21, and the follow-up control flag Ffw is set. Thereafter, the process proceeds to step S50. On the other hand, when the follow-up running control is not started, the process proceeds to step S30.

  Here, in this embodiment, when it is determined that the inter-vehicle distance Lrel is equal to or less than the control start inter-vehicle distance Ls, it is determined that the follow-up control is started. Instead, when the accelerator opening AP is larger than a predetermined value (predetermined accelerator opening) and it is determined that the inter-vehicle distance Lrel is equal to or less than the control start inter-vehicle distance Ls, a follow-up is performed. It is also possible to start control of traveling. The predetermined value (predetermined accelerator opening) is the minimum accelerator opening at which the driver can determine that he / she intends to accelerate by depressing the accelerator pedal 19, that is, the driver intentionally presses the accelerator. This is the minimum accelerator opening that can be determined to be operating (depressing), and is an accelerator opening that is determined in advance by experiments or the like. Even when the accelerator opening is smaller than the predetermined value (predetermined accelerator opening), the current inter-vehicle distance Lrel is less than or equal to a predetermined distance that is smaller than the control start inter-vehicle distance Ls. In this case, it is determined that the control is started.

In step S30, it is determined whether the inter-vehicle distance Lrel with the preceding vehicle is smaller than the control start inter-vehicle distance Ls. If the condition is satisfied, the process proceeds to step S40. If the condition is not satisfied, the process is terminated and the process returns. It should be noted that the control start inter-vehicle distance Ls may coincide with the previous value Lz of the target inter-vehicle distance L or may be different.
As the initial values of the control start inter-vehicle distance Ls and the target inter-vehicle distance L, preset values are adopted. You may give with a map etc. based on speed.
In step S40, the current accelerator opening AP is set to the accelerator opening initial value AP0, the process ends, and the process returns.
AP0 = AP

When it is determined that the following traveling control is being performed and the process proceeds to step S50, it is determined whether the inter-vehicle distance Lrel with the preceding vehicle coincides with the previous value Lz of the target inter-vehicle distance L that is the current target inter-vehicle distance L. . Specifically, the absolute value of the difference between the inter-vehicle distance Lrel from the preceding vehicle and the previous target value Lz of the target inter-vehicle distance L, which is the current target inter-vehicle distance L, is an accelerator opening initial value AP0 update determination threshold value ( α) It is determined whether or not. If the condition is satisfied, the process proceeds to step S60. If the condition is not satisfied, the process is terminated as it is.
| Lref−Lz | <α
Here, the accelerator opening initial value AP0 update determination threshold α is a threshold that can be determined so that the inter-vehicle distance Lrel with the preceding vehicle substantially coincides with the current target inter-vehicle distance L, and the control error or Set in consideration of sensor accuracy. For example, α = 1 m is set.

In step S60, the current accelerator opening AP is set to the accelerator opening initial value AP0, and the process ends.
AP0 = AP
Here, the vehicle head time THW based on the vehicle speed may be used as the inter-vehicle distance. The vehicle head time THW is the time required for the host vehicle MM to reach the position of the preceding vehicle ahead in the traveling direction.

  Next, the target inter-vehicle distance setting unit 42 determines the accelerator opening initial value AP0, the accelerator opening AP of the accelerator pedal acquired by the accelerator opening sensor 2, and the host vehicle speed Vh based on the detection by the wheel speed sensor 7. The target inter-vehicle distance L is set from the inter-vehicle distance Lrel and the relative speed ΔV detected by the preceding vehicle information detection sensor 3. Here, the relative speed ΔV is positive in the direction in which the host vehicle approaches the preceding vehicle.

The processing of the target inter-vehicle distance setting unit 42 will be described with reference to the flowchart shown in FIG.
First, in step S100, the accelerator opening initial value AP0 set by the accelerator opening initial value setting unit 41, the accelerator opening AP operated by the driver input from the accelerator opening sensor 2, and the detection of the wheel speed sensor 7 are detected. Based on the vehicle speed Vh based on Then, the target inter-vehicle distance L is calculated by processing in subsequent steps.

  First, in step S110, it is determined from the follow-up control flag Ffw set by the accelerator opening initial value setting unit 41 and the previous value Ffwz whether or not the follow-up running control is started. When the previous value Ffwz of the follow-up control flag is in the reset state and the follow-up control flag Ffw is in the set state, it is determined that the control is started, and in other cases, it is not determined that the control is started. When it is determined that the control is started, the process proceeds to step S120. On the other hand, when it is not determined that the control is started, the process proceeds to step S150.

In step S120, the relative target inter-vehicle distance ΔLrel corresponding to the vehicle state when the control is started is calculated. The relative target inter-vehicle distance ΔLrel is calculated, for example, from the vehicle state based on the inter-vehicle distance Lrel with the preceding vehicle, the relative speed ΔV of the preceding vehicle based on information from the preceding vehicle information detection sensor 3, and the own vehicle speed Vh. For example, it is calculated based on the following formula (4).
ΔLrel = GainL × GainV × Lrel (4)
Here, GainL is a gain according to the inter-vehicle distance Lrel, and is set to be a large value when the inter-vehicle distance Lrel with the preceding vehicle at the start of control is large compared to when the inter-vehicle distance Lrel is small. To do. For example, GainL is determined based on the map shown in FIG. That is, when the inter-vehicle distance Lrel is large, GainL is set to a relatively large value.

  Gain V is a gain corresponding to the relative speed ΔV, and is set to have a larger value when the relative speed ΔV is larger than when the relative speed ΔV is small. For example, Gain V is determined based on the map shown in FIG. 7, that is, when the accelerator pedal is depressed and the control is started when the relative speed ΔV is large, the driver's intention is to further reduce the inter-vehicle distance Lrel. Presumed to be. For this reason, when the relative speed is large, Gain V is set to a relatively large value.

Next, in step S130, an initial value of the target inter-vehicle distance L is set based on Expression (6) using the relative target inter-vehicle distance ΔLrel. Then, the process ends and returns.
L = Lrel−ΔLrel (6)
When the control is not started, the process proceeds to step S150, and the change amount ΔL of the target inter-vehicle distance L is calculated based on the accelerator pedal opening AP.
Specifically, first, an accelerator opening change amount ΔAP, which is an opening difference between the accelerator opening initial value AP0 and the current accelerator opening AP, is obtained based on the following equation (7).
ΔAP = AP−AP0 (7)

  Next, a change amount ΔL of the target inter-vehicle distance L is obtained based on the accelerator opening change amount ΔAP. The amount of change ΔL of the target inter-vehicle distance L is a value that is substantially inversely proportional to the amount of change in the accelerator opening as shown in FIG. However, as shown in FIG. 8, a dead zone is provided in the vicinity of the value of the accelerator opening AP being zero. By providing a dead zone, the influence of the accelerator pedal movement not intended by the driver is eliminated.

Here, the change amount ΔL of the target inter-vehicle distance L has an upper limit value ΔLmax in order to prevent a sudden inter-vehicle change when the driver closes the accelerator. The upper limit value ΔLmax may be a fixed value or may be set according to the vehicle state. When the accelerator is fully closed, the change amount ΔL of the target inter-vehicle distance L is set to the upper limit value ΔLmax of the change amount of the target inter-vehicle distance L according to the following equation.
ΔL = min (ΔL, ΔLmax)

Next, in step S160, the target inter-vehicle distance L is calculated from the previous value Lz of the target inter-vehicle distance L and the change amount ΔL of the target inter-vehicle distance L based on the equation (6). Then, the process ends and returns.
L = Lz + ΔL (6)
Here, instead of the previous value Lz of the target inter-vehicle distance L, an initial value of the target inter-vehicle distance L may be adopted.

Further, the target inter-vehicle distance L has a lower limit value Lmin for maintaining a minimum inter-vehicle distance from the preceding vehicle, and the target inter-vehicle distance L is set to a value equal to or greater than Lmin by the following equation. This lower limit Lmin may be a fixed value or may be changed according to the vehicle state.
L = max (L, Lmin)
Further, when the accelerator opening change amount ΔAP is small, the dead zone is set in advance or set with a map or the like in order to eliminate the influence of the accelerator pedal movement not intended by the driver.
As the target inter-vehicle distance L, the vehicle head time THW (= inter-vehicle distance Lrel / own vehicle speed) obtained by standardizing the inter-vehicle distance Lrel with the own vehicle speed may be used as described above.

  Next, the inter-vehicle distance servo unit 43 determines the inter-vehicle distance Lrel from the preceding vehicle based on the inter-vehicle distance Lrel from the preceding vehicle input from the preceding vehicle information detection sensor 3 and the host vehicle speed Vh. For example, servo control represented by PID control is performed. The inter-vehicle distance servo unit 43 outputs a target throttle opening TH0, a target braking force Br_xx (where xx is FL, FR, RL, RR) of each wheel, and a throttle opening THap obtained by converting the accelerator opening.

The processing of the inter-vehicle distance servo unit 43 will be described with reference to the flowchart shown in FIG.
First, in step S200, the inter-vehicle distance Lrel from the preceding vehicle based on the detection by the preceding vehicle information detection sensor 3 and the target inter-vehicle distance L set by the target inter-vehicle distance setting unit 42 are read.
Next, in step S210, a target acceleration Gout for servo control for making the inter-vehicle distance Lrel with the preceding vehicle coincide with the target inter-vehicle distance L is calculated.

The target acceleration Gout is obtained by calculating a deviation ΔLservo between the inter-vehicle distance Lrel and the target inter-vehicle distance L as shown in the following equation (8), and the target acceleration for reducing the deviation is expressed by, for example, the following ( 9) Calculate based on the equation.
ΔLservo = L−Lrel (8)
Gout = Pservo × ΔLservo
+ Dservo × ΔLservo
+ Iservo × ΔLservo (9)
Here, Pservo, Dservo, and Iservo represent PID control gains, which respectively indicate a proportional gain, a differential gain, and an integral gain.

Next, in step S220, a command value for braking / driving force is calculated.
That is, the target throttle opening TH0, the target brake force Br_xx (where xx is FL, FR, RL, RR) of each wheel, the target acceleration Gout, and the vehicle acceleration Geng that can be generated by the engine brake (10) It is determined by equation (11). The function f (x) is a function for obtaining a throttle opening when the vehicle acceleration x is generated by engine braking, and a map or the like may be used. W represents the weight of the host vehicle MM.
When Gout ≧ Geng (10)
TH0 = f (Gout)
Br_xx = 0
In the case of Gout <Geng (11)
TH0 = f (Gout)
Br_xx = {(Gout−Geng) × W} / 4

The end processing unit 44 outputs the target throttle opening TH0 obtained in step S220 and the target brake force Br_xx (where xx is FL, FR, RL, RR) of each wheel.
Next, in step S230, from the accelerator opening AP of the accelerator pedal detected by the accelerator opening sensor 2, the accelerator opening AP is converted into a throttle opening using a preset map or the like, and the accelerator opening is converted. The determined throttle opening THap is determined.
Next, the end processing unit 44 determines the end of control for follow-up travel from the inter-vehicle distance Lrel with the preceding vehicle input from the preceding vehicle information detection sensor 3, and performs end control when determining that the control is ended.
Here, when the inter-vehicle distance Lrel is equal to or greater than a preset control end distance Lend (> L), it is determined that the control is ended.

When it is determined that the control is completed, the control is shifted to the end control, and the target throttle opening TH1 at the end of the control is calculated from the accelerator opening AP inputted from the accelerator opening sensor 2 and the target throttle opening TH0, and the control ends. In addition to outputting the target throttle opening TH1, the target brake force Br_xx of each wheel is set to zero and output.
Here, except at the end of control, the target throttle opening TH0 calculated by the inter-vehicle distance servo unit 43 and the target brake force Br_xx of each wheel are output.

The processing of the end processing unit 44 will be described based on the flowchart shown in FIG.
First, in step S300, the current accelerator opening AP detected by the accelerator opening sensor 2, the inter-vehicle distance Lrel from the preceding vehicle based on the detection by the preceding vehicle information detection sensor 3, the current throttle opening TH, and the accelerator opening. Follow-up control flag Ffw set by the degree initial value setting unit 41, throttle opening THap obtained by converting the accelerator opening generated by the inter-vehicle distance servo unit 43, target throttle opening TH0, and target brake force Br_xx ( ; Xx reads FL, FR, RL, RR).

Next, in step S301, it is determined whether follow-up control is being performed. Specifically, it is determined whether or not the follow-up control flag Ffw set by the accelerator opening initial value setting unit 41 is set. If the above condition is satisfied, the process proceeds to step S310 in order to perform the calculation process during follow-up control. If the above condition is not satisfied, the process proceeds to step S302.
Next, in step S302, the target throttle opening TH0 and the target brake force Br_xx (where xx is FL, FR, RL, RR) of each wheel are values obtained when the following control is not being performed as in the following equation. And the process proceeds to step S340.
TH0 = THap
Br_xx = 0

Next, in step S310, it is determined whether to execute end control. Specifically, it is determined whether the inter-vehicle distance Lrel with the preceding vehicle is greater than the control end distance Lend for determining the end of the follow-up control. If the above condition is satisfied, the process proceeds to step S311 to execute the end control calculation process. In step S311, the throttle opening difference ΔTHend at the end of control is calculated from the throttle opening THend converted from the accelerator opening at the end of control and the target throttle opening TH0end at the end of control. The throttle opening THend at the end of control is the accelerator opening generated by the inter-vehicle distance servo unit 43 when it is determined that the inter-vehicle distance Lrel with the preceding vehicle is greater than the control end distance Lend for determining the end of the follow-up control. Is the converted throttle opening THap. The target throttle opening TH0end at the end of control is the target throttle opening TH0 when it is determined that the inter-vehicle distance Lrel with the preceding vehicle is greater than the control end distance Lend for determining the end of the follow-up control. Here, the throttle opening difference ΔTHend at the end of the control is calculated from the throttle opening THend at the end of the control and the target throttle opening TH0end at the end of the control, as shown in the following equation.
ΔTHend = THend−TH0end

  Thereafter, the process proceeds to step S320. If the above condition is not satisfied, the process proceeds to step S312. In step S312, the target throttle opening TH0 generated by the inter-vehicle distance servo unit 43 and the target brake force Br_xx (where xx is FL, FR, RL, RR) of each wheel are held as control targets. Thereafter, the process proceeds to step S340. The control end distance Lend may be a fixed value or a value according to the vehicle state.

If the control start condition is satisfied during the end control, the follow-up running control is resumed.
In step S320, it is determined whether the accelerator opening AP and the current throttle opening (TH) are both fully open or fully closed. When the condition is satisfied, the process proceeds to step S321, the follow-up control flag Ffw set by the accelerator opening initial value setting unit 41 is reset, the accelerator opening initial value AP0 is cleared to the initial value, and the end control is performed. Exit and return. If the condition is not satisfied, the process proceeds to step S330.

Next, in step S330, the target throttle opening TH0 is changed to the target throttle opening TH1 at the end of control, as shown in equations (12) and (13). Further, the target brake force Br_xx (; xx is FL, FR, RL, RR) of each wheel is changed to a value during end control as shown in the equations (12) and (13).
Here, the accelerator opening AP corresponding to the current throttle opening TH is defined as the accelerator opening APth. The accelerator opening APth is converted from the current throttle opening TH to the accelerator opening using a preset map or the like. THz is the previous value of the throttle opening TH.
When AP ≧ APth (12)
TH1 = TH−ΔTHend
TH0 = TH1
Br_xx = 0
If AP <APth (13)
TH1 = max (THz-THstep, THap)
TH0 = TH1
Br_xx = 0
Here, the throttle opening difference ΔTHend at the end of the control is calculated in step S311.

Further, THstep is an accelerator opening decrease amount set in advance as a value for decreasing in one control cycle.
Here, when the accelerator opening AP operated by the driver is larger than the accelerator opening corresponding to the current throttle opening TH at the end of the control, the throttle opening is increased to match the accelerator opening. The vehicle accelerates unintentionally. In order to prevent this, if it is determined that the accelerator opening AP operated by the driver is larger than the accelerator opening corresponding to the current throttle opening TH at the end of the control, the relative relationship between the accelerator opening and the throttle opening is determined. Control to maintain.

On the other hand, when the accelerator opening AP operated by the driver is smaller than the accelerator opening corresponding to the current throttle opening TH, the throttle opening is set so that the accelerator opening = the accelerator opening corresponding to the throttle opening. Is gradually reduced so that it matches the accelerator opening.
Next, in step S340, the target throttle opening TH0 and the target brake force Br_xx (where xx is FL, FR, RL, RR) of each wheel are output to the throttle opening control unit 5 and the brake controller 6.

(Operation other)
For example, when the host vehicle MM approaches the preceding vehicle below the control start distance with the accelerator pedal depressed, follow-up running control for the preceding vehicle is started.
At this time, the accelerator opening AP when the control is started is set as the accelerator opening initial value AP0.
In the present embodiment, the target inter-vehicle distance L is set according to the state of the vehicle at the start of control. For example, when the relative speed at the start of control is large or the inter-vehicle distance Lrel is large, the driver's intention to approach the preceding vehicle is estimated, so the target inter-vehicle distance L is set relatively small.

  In addition, if the accelerator pedal is depressed more than the accelerator opening initial value AP0 that is the accelerator opening AP at the start of control during the follow-up control, the driver's intention to approach the preceding vehicle is estimated. Then, the target inter-vehicle distance L is corrected to decrease. On the other hand, if the accelerator pedal is returned from the accelerator opening initial value AP0, which is the accelerator opening AP at the start of control, during the follow-up running control, the driver's intention to leave the preceding vehicle is estimated. Therefore, the target inter-vehicle distance L is corrected to be increased. With the above correction, the target inter-vehicle distance L is set according to the driver's intention.

FIG. 11 shows an example of a timing chart at the time of following traveling control.
When the inter-vehicle distance Lrel with the preceding vehicle is the target inter-vehicle distance L and the accelerator pedal opening AP is constant, the target inter-vehicle distance L does not change. If the preceding vehicle decreases the speed in this state, the speed of the host vehicle MM also decreases accordingly, and the target inter-vehicle distance L is controlled to be constant.
Further, when the driver depresses the accelerator pedal and changes in the direction in which the accelerator opening AP increases, the target inter-vehicle distance L decreases accordingly. In this case, the inter-vehicle distance Lrel is shortened by increasing the speed of the host vehicle MM in order to shorten the inter-vehicle distance Lrel with the preceding vehicle. When the inter-vehicle distance Lrel becomes the target inter-vehicle distance L, the braking / driving force is controlled so that the relative speed with the preceding vehicle becomes zero.

Further, when the driver returns the accelerator pedal, the target inter-vehicle distance L increases accordingly. In this case, the host vehicle speed is reduced and control is performed such that the inter-vehicle distance Lrel from the preceding vehicle is increased.
Subsequently, when the accelerator pedal opening AP is returned to the extent that it is determined that the accelerator is off, the target inter-vehicle distance L is set to an upper limit value, the follow-up running control is terminated, the end control is performed, and then the control is stopped.

FIG. 12 shows an example of a timing chart at the end control.
Time t1 is a time point when it is determined that the follow-up running control is ended and the end control is started.
When the follow-up running control before time t1 is performed, even if the accelerator opening AP is constant and the target inter-vehicle distance L is constant, the inter-vehicle distance Lrel is set according to the speed change of the preceding vehicle. The engine 9 throttle opening is controlled so that the inter-vehicle distance L is obtained. FIG. 12 illustrates a case where the throttle opening is decreased in order to decrease the speed of the host vehicle MM following the decrease in speed of the preceding vehicle.

Thus, during the follow-up traveling control, the correlation between the accelerator opening AP and the throttle opening is in a state of being deviated. For this reason, if the follow-up running control is finished and the control is finished as it is, if the accelerator opening AP is larger than the accelerator opening value corresponding to the current throttle opening, the vehicle is contrary to the driver's intention. Will accelerate.
For this reason, in this embodiment, when it is determined that the follow-up running control is to be ended, the end control is performed.

That is, in the example shown in FIG. 12, since the accelerator opening AP is larger than the accelerator opening value corresponding to the current throttle opening, it corresponds to the current accelerator opening AP and the current throttle opening. The opening difference between the accelerator opening values is kept constant or nearly constant. This prevents the host vehicle MM from accelerating against the driver's intention.
When the driver returns the accelerator pedal, the throttle opening decreases accordingly. In this example, after the throttle opening first becomes zero, the accelerator opening AP also becomes zero. As a result, it is determined that the accelerator opening AP is equal to the accelerator opening corresponding to the current throttle opening, and the end control is ended.

  However, in the above end control, when the driver depresses the accelerator pedal until the accelerator opening AP is fully opened, the throttle opening is also increased by a predetermined increase rate, and the throttle corresponding to the accelerator opening fully opened. Increase to the opening. Then, it is determined that the accelerator opening AP is equal to the accelerator opening value corresponding to the current throttle opening, and the end control is ended. As a result, acceleration of the host vehicle MM according to the driver's intention is realized.

On the other hand, when the accelerator opening AP is lower than the accelerator opening value corresponding to the current throttle opening at the end of the follow-up control, the throttle opening is gradually reduced at a predetermined reduction rate, and the accelerator opening When the AP coincides with the accelerator opening value corresponding to the current throttle opening, the end processing is ended.
Even during the end control, if the start condition of the follow-up running control is satisfied, the process shifts to the follow-up running control.

  Here, the preceding vehicle information detection sensor 3 constitutes an inter-vehicle distance measuring means. The accelerator opening sensor 2 constitutes accelerator opening detecting means. The inter-vehicle distance servo unit 43 constitutes the inter-vehicle distance control means 4C. The accelerator opening initial value setting unit 41 constitutes accelerator opening initial value setting means 4A. Steps S150 and S160 constitute target inter-vehicle distance correction means. The termination processing unit 44 constitutes termination processing control means.

(Effect of this embodiment)
(1) The inter-vehicle distance control means 4C starts the follow-up traveling control when it is determined that the inter-vehicle distance Lrel between the preceding vehicle existing in the traveling direction of the host vehicle MM and the host vehicle MM is equal to or less than a preset control start distance. Then, as the following traveling control, the throttle opening of the own vehicle is controlled so that the inter-vehicle distance Lrel measured by the inter-vehicle distance measuring means becomes the target inter-vehicle distance L for following traveling, and the braking / driving force of the own vehicle MM is controlled. To control. The accelerator opening initial value setting means 4A sets the accelerator opening detected by the accelerator opening detecting means when the follow-up running control is started as the accelerator opening initial value AP0. The target inter-vehicle distance correction means corrects the target inter-vehicle distance L based on the accelerator opening initial value AP0 set by the accelerator opening initial value setting means 4A and the accelerator opening detected by the accelerator opening detecting means. To do. That is, the target inter-vehicle distance correction means corrects the target inter-vehicle distance by decreasing the accelerator opening when the accelerator opening detected by the accelerator opening detection means is larger than the initial accelerator opening. On the other hand, when the accelerator opening detected by the accelerator opening detecting means is small, the target inter-vehicle distance is increased and corrected.

  The target inter-vehicle distance L is decreased according to the accelerator opening increase amount from the set accelerator opening initial value AP0, and the target inter-vehicle distance L is set according to the accelerator opening decrease from the set accelerator opening initial value AP0. Increase. For this reason, even if the initial value of the target inter-vehicle distance L is not set to be large, the inter-vehicle distance range in which the follow-up control can be performed can be increased, and the follow-up running control without a sense of incongruity for the driver is possible.

(2) When the accelerator opening initial value setting means 4A determines that the inter-vehicle distance Lrel measured by the inter-vehicle distance measuring means coincides with the target inter-vehicle distance L after starting the follow-up running control, The accelerator opening is reset to the accelerator opening initial value AP0.
As a result, the accelerator opening initial value AP0 can be updated according to the vehicle state of the host vehicle MM.

(3) When the end processing control means determines that the inter-vehicle distance Lrel measured by the inter-vehicle distance measuring means is greater than a predetermined control end distance for ending the follow-up running, the end-processing control means Perform termination processing control.
Normally, during follow-up running, the accelerator opening AP and the throttle opening are deviated. It is possible to terminate the control after eliminating this divergence.

(4) When the termination processing control means determines that the current accelerator opening AP is larger than the accelerator opening corresponding to the current throttle opening, the accelerator opening AP and the accelerator corresponding to the throttle opening are determined. The throttle opening is controlled so as to maintain the opening difference from the opening.
Accordingly, it is possible to suppress sudden acceleration of the host vehicle MM caused by setting the current throttle opening to a value corresponding to the accelerator opening AP.

(5) When it is determined that the current accelerator opening AP is smaller than the accelerator opening corresponding to the current throttle opening, the end processing control means sets the throttle opening to the current accelerator opening AP. Move closer to the corresponding throttle opening.
This makes it possible to bring the current throttle opening closer to the current accelerator opening AP.

(6) When the termination processing control means determines that the current accelerator opening AP is fully open or fully closed, it brings the throttle opening closer to the throttle opening corresponding to the current accelerator opening AP.
This makes it possible to bring the current throttle opening closer to the current accelerator opening AP.
(7) When it is determined that the throttle opening coincides with the throttle opening corresponding to the current accelerator opening AP, the end process control means ends the end process control for ending the follow-up running.
Thereby, it is possible to suppress the occurrence of inadvertent acceleration of the host vehicle MM from the control to the end of the control.

2 accelerator opening sensor 3 preceding vehicle information detection sensor 4 inter-vehicle controller 4A accelerator opening initial value setting means 4B target inter-vehicle distance means 4C inter-vehicle distance control means 41 accelerator opening initial value setting unit 42 target inter-vehicle distance setting unit 43 inter-vehicle distance Servo unit 44 End processing unit 5 Throttle opening control unit 6 Brake controller 7 Wheel speed sensor 8 Throttle opening sensor 9 Engine 19 Accelerator pedal AP Accelerator opening AP0 Accelerator opening initial value Br_xx Target brake force Gout Target acceleration L Target inter-vehicle distance Lend Control end distance Lrel Inter-vehicle distance Ls Control start inter-vehicle distance TH Throttle opening Vp Relative speed

Claims (8)

An inter-vehicle distance measuring means for measuring an inter-vehicle distance between a preceding vehicle and the own vehicle existing in the traveling direction of the own vehicle;
An accelerator opening detecting means for detecting an accelerator opening which is an operation amount of an accelerator pedal operated by a driver;
When it is determined that the inter-vehicle distance measured by the inter-vehicle distance measuring means is equal to or less than the preset control start distance, the follow-up running control is started. As the follow-up running control, the inter-vehicle distance measured by the inter-vehicle distance measuring means An inter-vehicle distance control means for controlling the throttle opening of the host vehicle to control the braking / driving force of the host vehicle;
An accelerator opening initial value setting means for setting the accelerator opening detected by the accelerator opening detecting means at the time of starting the follow-up running control as an accelerator opening initial value;
Target inter-vehicle distance correction means for correcting the target inter-vehicle distance based on the accelerator opening initial value set by the accelerator opening initial value setting means and the accelerator opening detected by the accelerator opening detecting means. ,
The target inter-vehicle distance correcting means corrects the target inter-vehicle distance by decreasing the accelerator opening when the accelerator opening detected by the accelerator opening detecting means is larger than the initial accelerator opening. An inter-vehicle distance control device, wherein when the accelerator opening detected by the accelerator opening detecting means is small, the target inter-vehicle distance is increased and corrected.   When the accelerator opening initial value setting means determines that the inter-vehicle distance measured by the inter-vehicle distance measuring means coincides with the target inter-vehicle distance after the follow-up running control is started, the accelerator opening when it is determined that they coincide with each other is determined. The inter-vehicle distance control device according to claim 1, wherein the inter-vehicle distance control device is reset to an accelerator opening initial value.   When it is determined that the inter-vehicle distance measured by the inter-vehicle distance measuring means is greater than a predetermined control end distance for ending the follow-up running, an end process control for executing an end process control for ending the follow-up running. The inter-vehicle distance control device according to claim 1 or 2, further comprising means.   When the current accelerator opening is determined to be larger than the accelerator opening corresponding to the current throttle opening, the end processing control means determines whether the accelerator opening and the accelerator opening corresponding to the throttle opening are 4. The inter-vehicle distance control device according to claim 3, wherein the throttle opening is controlled so as to maintain the opening difference.   When it is determined that the current accelerator opening is smaller than the accelerator opening corresponding to the current throttle opening, the end processing control means sets the throttle opening to the throttle opening corresponding to the current accelerator opening. The inter-vehicle distance control device according to claim 3 or 4, wherein the inter-vehicle distance control device is close to the degree.   The termination processing control means, when it is determined that the current accelerator opening is fully open or fully closed, the throttle opening closes to the throttle opening corresponding to the current accelerator opening. The inter-vehicle distance control device according to claim 5.   The termination processing control means ends the termination processing control for terminating the follow-up travel when it is determined that the throttle opening coincides with the throttle opening corresponding to the current accelerator opening. The inter-vehicle distance control device according to any one of claims 3 to 6. When it is determined that the inter-vehicle distance between the preceding vehicle and the own vehicle existing in the traveling direction of the host vehicle is equal to or less than the preset control start distance, the follow-up travel control is started. Control the braking / driving force of the vehicle so that the distance between vehicles is
When the accelerator opening detected by the accelerator opening detecting means at the time when the follow-up running control is started is set as an accelerator opening initial value, and the current accelerator opening is larger than the set accelerator opening initial value The vehicle distance control method includes correcting the decrease in the target vehicle distance and increasing the target vehicle distance when the current accelerator opening is small.

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