JP2004042725A - Running controller for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress sense of incongruity that a driver has by removing braking force quickly even when follow-up running control is released so that acceleration and deceleration speed is gradually changed and both preceding vehicles ahead own vehicle leave by setting own vehicle speed below set vehicle speed. <P>SOLUTION: When a running condition becomes a deceleration condition and own vehicle speed becomes below the set vehicle speed while follow-up running control for the preceding vehicle is performed, target acceleration and deceleration speed G<SB>OFF</SB><SP>*</SP>for releasing control is set to "O" (step S29) when the preceding vehicle detected by a vehicle-to-vehicle distance sensor 12 does not exist (discrimination at step S21 is "NO") while releasing follow-up running control so that acceleration change becomes gradual to quicken the release of the follow-up running control. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle travel control device that performs speed control for following a preceding vehicle while maintaining a distance between the vehicle and the preceding vehicle.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as this type of vehicle travel control device, for example, a device described in Japanese Patent Application Laid-Open No. 11-278096 has been proposed.
In this conventional example, when the following speed control is performed while maintaining a predetermined inter-vehicle distance with respect to the preceding vehicle, if the own vehicle speed becomes equal to or less than the set vehicle speed due to deceleration according to the preceding vehicle, an alarm is issued and By maintaining the negative target acceleration / deceleration at this time for a predetermined time and gradually increasing the value toward "0", the rate of change is moderated. When the target acceleration / deceleration becomes "0", A traveling control device for a vehicle that cancels each of the control and the warning is described.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional vehicle travel control device, even if the own vehicle speed falls below the set vehicle speed, the following travel control is not released until the target acceleration / deceleration becomes “0”. Therefore, before the target acceleration / deceleration becomes “0”, for example, even if the preceding vehicle leaves from the front of the own vehicle, the following cruise control is not released, and the target acceleration / deceleration is maintained until the target acceleration / deceleration becomes “0”. Since the target braking pressure according to the speed is calculated, there is an unsolved problem that the braking force remains even though the preceding vehicle does not already exist, giving the driver an uncomfortable feeling.
[0004]
Therefore, the present invention has been made by focusing on the unsolved problem of the above-described conventional example, and when the own vehicle speed falls below the set vehicle speed, when the follow-up traveling control is released such that the acceleration / deceleration change becomes gentle, For example, it is an object of the present invention to provide a vehicular travel control device capable of suppressing a sense of discomfort given to a driver by quickly removing a braking force when a preceding vehicle in front of the host vehicle leaves.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, in the vehicle traveling control device according to the present invention, the target acceleration / deceleration setting means includes: The speed is set, the travel control means controls the travel so as to achieve the target acceleration / deceleration, and the travel control canceling means changes the acceleration slowly when the own vehicle speed detected by the vehicle speed detection means is equal to or less than the set vehicle speed. Thus, while the traveling control by the traveling control unit is released, when the preceding vehicle to be detected by the inter-vehicle distance detecting unit no longer exists, the release of the traveling control by the traveling control unit is hastened.
[0006]
【The invention's effect】
According to the vehicle travel control device of the present invention, the target acceleration / deceleration setting means sets the target acceleration / deceleration so that the inter-vehicle distance to the preceding vehicle detected by the inter-vehicle distance detection means matches the target inter-vehicle distance, and travels. The control means controls the travel so as to achieve the target acceleration / deceleration, and the travel control canceling means controls the travel so that when the vehicle speed detected by the vehicle speed detection means is equal to or less than the set vehicle speed, the acceleration change becomes gentle. When the preceding vehicle to be detected by the inter-vehicle distance detection means no longer exists while the travel control by the means is released, the release of the travel control by the travel control means is accelerated. The braking force is quickly removed when the following driving control is released so that the change in acceleration / deceleration becomes gradual by, for example, even if the preceding vehicle in front of the host vehicle departs. There is an advantage that it is possible to suppress the sense of discomfort given to the driver by.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a first embodiment in which the present invention is applied to a rear wheel drive vehicle. In the drawing, 1FL and 1FR are front wheels as driven wheels, 1RL and 1RR are drive wheels. The rear wheels 1RL and 1RR are driven to rotate by the driving force of the engine 2 being transmitted through the automatic transmission 3, the propeller shaft 4, the final reduction gear 5 and the axle 6.
[0008]
Each of the front wheels 1FL, 1FR and the rear wheels 1RL, 1RR is provided with a disc brake 7 for generating a braking force, and the braking oil pressure of these disc brakes 7 is controlled by a braking control device 8. The braking control device 8 is configured to generate a braking oil pressure in response to depression of a brake pedal (not shown) and to generate a braking oil pressure in accordance with a braking pressure command value from the travel control controller 20.
[0009]
Further, the engine 2 is provided with an engine output control device 9 for controlling the output. The engine output control device 9 controls the engine speed by adjusting the opening of the throttle valve and controlling the engine speed by adjusting the opening of the idle control valve. Although a control method is conceivable, in the present embodiment, a method of adjusting the opening of the throttle valve is employed.
[0010]
Further, the automatic transmission 3 is provided with a transmission control device 10 for controlling the shift position. When an up / downshift command value TS is input from a travel control controller 20 described later, the transmission control device 10 performs upshift or downshift control of the shift position of the automatic transmission 3 in response to the input. Is configured.
[0011]
Further, an inter-vehicle distance sensor 12 including a radar device as an inter-vehicle distance detecting means for detecting an inter-vehicle distance with a preceding vehicle is provided below the vehicle body on the front side of the vehicle. Further, the vehicle is provided with wheel speed sensors 13L and 13R for detecting the wheel speeds of the front wheels 1FL and 1FR.
Output signals of the inter-vehicle distance sensor 12 and the wheel speed sensors 13L and 13R are input to a travel control controller 20, and the inter-vehicle distance D detected by the inter-vehicle distance sensor 12 and the wheel speed sensor Wheel speed V detected at 13L, 13R_WL, V_WRBy controlling the brake control device 8, the engine output control device 9, the transmission control device 10, and the alarm circuit 21 composed of, for example, a buzzer based on the The cruise control is performed for the tracing. During the follow-up traveling control, the own vehicle decelerates due to the deceleration of the preceding vehicle or the vehicle interrupting from another lane, and the vehicle speed becomes the set vehicle speed V.₀In the following cases, the alarm circuit 21 is driven to issue an alarm, and the target acceleration / deceleration is returned to zero at a gradual rate of change after holding the target acceleration / deceleration for the set holding time. When the vehicle departs from the vehicle, control release processing is performed so that the release of the follow-up traveling control is expedited.
[0012]
Next, the operation of the first embodiment will be described with reference to a flowchart showing the traveling control process of FIG. 2 executed by the traveling control controller 20.
This running control process is executed as a timer interrupt process for a predetermined main program every predetermined time (for example, 10 msec). First, in step S1, a control state flag FC indicating whether or not the following running control state is set to “1”. Is determined, and if the determination result is that the control state flag FC = 0, it is determined that the follow-up traveling control is not being executed, and the timer interrupt processing is terminated and the predetermined Return to the main program. On the other hand, when the result of this determination is that the control state flag FC = 1, it is determined that the following running control is being executed, and the routine proceeds to step S2.
[0013]
In this step S2, the inter-vehicle distance D from the actual preceding vehicle detected by the inter-vehicle distance sensor 12 is read. In the following step S3, the wheel speed V detected by the wheel speed sensors 13L and 13R is read._WL, V_WRIs read, and the average of these values is obtained to calculate the own vehicle speed V.
Next, the process proceeds to step S4, in which the host vehicle speed V and the host vehicle are set to the rear L of the current preceding vehicle.₀Time T to reach position [m]₀(Inter-vehicle time) and the target inter-vehicle distance D between the preceding vehicle and the host vehicle according to the following equation (1).^*Is calculated.
[0014]
D^*= V × T₀+ D₀・ ・ ・ ・ ・ ・ (1)
By adopting the concept of the inter-vehicle time, the inter-vehicle distance is set to increase as the vehicle speed increases. Note that D₀Is the inter-vehicle distance when stopped.
Next, the routine proceeds to step 5, where the inter-vehicle distance D is equal to the target inter-vehicle distance D.^*It is determined whether the following condition is satisfied.^*, The following distance D is the target following distance D^*It is determined that it is possible to reduce the inter-vehicle distance as an acceleration state, and the process proceeds to step 6. In this step S6, the preset target vehicle speed V^*And the target acceleration / deceleration G according to the following equation (2)._FB ^*Is calculated and updated and stored in the acceleration / deceleration storage area of the memory, and then the process proceeds to step S8. Note that K_AAnd L_AIs a constant.
[0015]
G_FB ^*= K_A× (V^*−V) + L_A・ ・ ・ ・ ・ ・ (2)
On the other hand, when the determination result of step S5 is D ≦ D^*, The following distance D is the target following distance D^*It is determined that it is shorter and it is necessary to increase the inter-vehicle distance as a deceleration state, and the process proceeds to step S7. In step S7, the target acceleration / deceleration G is calculated based on the following equation (3)._FB ^*Is calculated and updated and stored in the acceleration / deceleration storage area of the memory, and then the process proceeds to step S8. Note that K_BAnd L_BIs a constant.
[0016]
G_FB ^*= K_B× (DD^*) -L_B・ ・ ・ ・ ・ ・ (3)
In step S8, the set vehicle speed V at which the own vehicle speed V becomes the minimum vehicle speed at which the preset following travel control can be maintained.₀Or less (for example, 30 km / h or less).₀, The process proceeds to step S9, where a release state flag FD indicating whether or not the control is in the release processing state is set._(N)Is set to “1” indicating the control release state, and then the process proceeds to step S10. On the other hand, when the determination result is V> V₀If it is, the process directly proceeds to step S10.
[0017]
In step S10, the release state flag FD_(N)Is set to “1”, and the result of this determination is the release state flag FD._(N)If = 1, the process proceeds to step S11, where an alarm output SA having a logical value of "1" is output to the alarm circuit 21, and the control release processing of FIG. Move to step S14. On the other hand, the result of the determination in step S10 is the control release flag FD._(N)If = 0, the process proceeds to step S13, where the target acceleration / deceleration G calculated in step S7 is calculated._FB ^*To the final target acceleration / deceleration G^*Then, the process proceeds to step S14.
[0018]
In step S14, a throttle opening command value θ for the engine control device 9 and an up / down shift command value TS for the transmission control device 10 are calculated, and an engine control process for outputting these is executed, and then the process proceeds to step S15. .
Here, the throttle opening command value θ is the final target acceleration / deceleration G^*In the acceleration state where is positive, the final target acceleration / deceleration G^*Is calculated, the throttle opening change amount Δθ that increases in the forward direction in accordance with the increase in the throttle opening. On the other hand, the final target acceleration / deceleration G^*Is negative, a predetermined value −G from “0”_SUntil the final target acceleration / deceleration G^*By calculating the throttle opening change amount Δθ that increases in the negative direction in accordance with the increase in the negative direction, and adding the throttle opening change amount Δθ to the current throttle opening command value θ, a new throttle opening The degree command value θ is calculated. Also, the final target acceleration / deceleration G^*Is a predetermined value -G_SIs exceeded, the throttle opening command value θ is set to “0” or a value in the vicinity thereof.
[0019]
The up / down shift command value TS is calculated based on the calculated throttle opening command value θ and the vehicle speed V by referring to a shift control map similar to the shift control in the automatic transmission 3 in the normal state. 3 is calculated.
In step S15, the final target acceleration / deceleration G set in step S13 or step S32 described below is set.^*Target braking pressure P based on_B ^*Is calculated, and this is output to the brake control device 8 as a brake pressure command value. Then, the timer interrupt process is terminated, and the process returns to the predetermined main program.
[0020]
Here, the target braking pressure P_B ^*Is the final target acceleration / deceleration G with reference to the braking pressure calculation map of FIG.^*Target braking pressure P according to_B ^*Is calculated. As shown in FIG. 4, this braking pressure calculation map has the final target acceleration / deceleration G on the horizontal axis.^*On the vertical axis, the target braking pressure P_B ^*And the final target acceleration / deceleration G^*Is positive and negative and the predetermined value -G_SUntil the target braking pressure P_B ^*Maintains “0” and the final target acceleration / deceleration G^*Is the predetermined value -G_SIncreases in the negative direction beyond the target braking pressure P_B ^*Is set to increase.
[0021]
Next, as shown in FIG. 3, a specific example of the control release processing in step S12 is described below. First, in step S21, the previous value FD of the release state flag is set._(N-1)Is read, and it is determined whether or not this is reset to “0”. The result of this determination is the release state flag FD._(N-1)If = 0, it is determined that the following running control release is started, and the process proceeds to step S22. In step S22, the target acceleration / deceleration G calculated in step S7 is calculated._FB ^*Is the target acceleration / deceleration G for releasing control._OFF ^*In the following step S23, the count value T of the holding time timer for monitoring the holding time of the target acceleration / deceleration is cleared to "0", and the process proceeds to step S24. On the other hand, the result of the determination in step S21 is that the control release flag FD_(N-1)If = 1, it is determined that control is being canceled, and the process directly proceeds to step S24.
[0022]
In this step S24, it is determined whether or not the detection of the preceding vehicle by the following distance sensor 12 is maintained. If the preceding vehicle is still detected, the process proceeds to step S25.
In step S25, the count value T of the holding time timer is set to a preset value T which is set to a time sufficient for the driver to reliably recognize the alarm issued by the alarm circuit 21._SETIt is determined whether or not this is the case. If this determination result is T <T_SETIf, it is determined that the holding state is to be continued, and the process proceeds to step S26, where the count value T of the holding time timer is incremented by "1", and then proceeds to step S32 described later. On the other hand, if the determination result of step S25 is T ≧ T_SETIf, it is determined that the holding time has elapsed, and the flow shifts to the step S27.
[0023]
In this step S27, as shown in the following equation (4), the current target acceleration / deceleration G for control release stored in step S23 is obtained._OFF ^*From the predetermined value ΔG_CLIs added to the new target acceleration / deceleration G for control release._OFF ^*After that, the process proceeds to step S28.
G_OFF ^*= G_OFF ^*+ ΔG_CL・ ・ ・ ・ ・ ・ (4)
In step S28, the control target acceleration / deceleration G_OFF ^*Is greater than or equal to “0” indicating the completion of the control release, and the result of this determination is G_OFF ^*If ≧ 0, it is determined that control release has been completed, and the routine goes to Step S29. When it is determined in the process of step S21 that there is no preceding vehicle to be detected by the inter-vehicle distance sensor 12, the process directly proceeds to step S29.
[0024]
In step S29, the control target acceleration / deceleration G_OFF ^*Is set to “0”, and this is updated and stored. Then, in a succeeding step S30, the release state flag FD is set._(N)And FD_(N-1)After resetting the control state flag FC to "0", the process proceeds to step S31. In this step S31, the alarm output SA having the logical value "0" is output to the alarm circuit 21, and then the process proceeds to step S32. In addition, the determination result of step S28 is G_OFF ^*If <0, it is determined that the control is being canceled, and the process directly proceeds to step S32.
[0025]
In step S32, the control release target acceleration / deceleration G updated and stored in step S23 or step S29._OFF ^*To the final target acceleration / deceleration G^*Then, the control release processing is terminated, and the processing returns to the traveling control processing of FIG.
Here, in the travel control processing of FIG. 2, the processing of steps S1 to S7 corresponds to the target acceleration / deceleration setting means, and the processing of steps S8 to S13 and the control release processing of FIG. 3 correspond to the travel control release means. The processes in steps S14 and S15 correspond to the traveling control means.
[0026]
Next, the operation of the above embodiment will be described.
Now, if the host vehicle is at the set vehicle speed V₀It is assumed that the vehicle is following the preceding vehicle while maintaining the above speed (the determination in step S1 is “Yes”).
At this time, the inter-vehicle distance D detected by the inter-vehicle distance sensor 12 is a target inter-vehicle distance D calculated based on the own vehicle speed V.^*, The target acceleration / deceleration G while distinguishing between deceleration and acceleration._FB ^*(Step S6 or step S8), and the target acceleration / deceleration G_FB ^*, The respective command values for the brake control device 8, the engine output control device 9, and the transmission control device 10 are calculated and output to control the traveling of the host vehicle (steps S14 and S15). . In this way, the own vehicle moves to the target inter-vehicle distance D with respect to the preceding vehicle traveling at a substantially constant speed.^*Is maintained, the final target acceleration / deceleration G^*However, as shown in FIG. 5B, it becomes substantially “0”.
[0027]
From this state, for example, when the preceding vehicle starts to decelerate, the following distance D detected by the following distance sensor 12 becomes equal to the target following distance D^*, The calculated target acceleration / deceleration G_FB ^*At time t₁And then increase to the negative side. This target acceleration / deceleration G_FB ^*Target braking pressure P calculated according to_BIs output to the braking control device 8, as shown in FIG. 5A, the target inter-vehicle distance D from the preceding vehicle.^*, The own vehicle speed V decreases.
[0028]
Then, as the preceding vehicle continues to decelerate, the own vehicle speed V becomes equal to the set vehicle speed V.₀When the vehicle speed falls below the threshold value, the cancellation of the follow-up running control for the preceding vehicle is started (the determination in step S10 is “Yes”).
First, the own vehicle speed V is equal to the set vehicle speed V.₀Time t₂The timer starts counting (steps S24 to S26), and the time t₂Target acceleration / deceleration G_FB ^*Is the target acceleration / deceleration G for releasing control._OFF ^*Is updated and stored (step S23). Further, an alarm output SA to the alarm circuit 21 is output in order to inform the driver that the follow-up traveling control is released (step S11). Then, the count value T of the timer is equal to the set value T._SETUntil it exceeds the target acceleration / deceleration G for control release._OFF ^*(The determination in step S25 is “No”), the own vehicle speed V decreases at a constant rate of change as shown in FIG.
[0029]
Thereafter, the count value T of the timer is changed to the set value T._SETTime t₃(The determination in step S24 is “Yes”), the target acceleration / deceleration G for control release_OFF ^*Has a predetermined positive value ΔG_CLIs gradually added (step S26), and as shown in FIG. 5B, the final target acceleration / deceleration G^*Gradually decreases toward “0”, and as a result, as shown in FIG. 5A, the own vehicle speed V can be gradually reduced.
[0030]
And the target acceleration / deceleration G for control release_OFF ^*At time t₄When "0" is exceeded ("Yes" in step S28), the output of the alarm output SA to the alarm circuit 21 is stopped (step S30), and the release of the following travel control is completed (step S1). The determination is “No”). Since the driver can sufficiently recognize the cancellation of the following travel control by the alarm that has been issued until then, the driver can immediately shift to the driving operation after the cancellation of the following travel control.
[0031]
By the way, during the cancellation of the following traveling control described above, for example, the preceding vehicle that has been following the vehicle is separated from the front of the own vehicle, or the own vehicle moves to another lane, and the preceding vehicle that is to be followed When is no longer present, it is desirable to be able to accelerate immediately. However, if the cancellation of the follow-up traveling control is continued so that the acceleration change becomes gentle, the final target acceleration / deceleration G, as shown in FIG.^*Until “0” is reached, the final target acceleration / deceleration G^*Target braking pressure P according to_BIs calculated, the braking force remains in spite of being able to accelerate.
[0032]
Therefore, during the cancellation of the following travel control, the time t₅When the preceding vehicle is no longer present (the determination in step S21 is "No"), the follow-up running control is immediately released so that the vehicle can be immediately accelerated. That is, the control release target acceleration / deceleration G_OFF ^*Is set to “0” (step S29), and as shown in FIG._BCan be set to “0”. Thus, by quickly removing the braking force generated in the host vehicle, it is possible to quickly shift to the acceleration operation without giving the driver an uncomfortable feeling.
[0033]
In the above-described embodiment, even if there is no preceding vehicle in front of the own vehicle during the cancellation of the following travel control, the vehicle shifts to the manual driving by the driver when the following travel control is released. Although the case has been described, the present invention is not limited to this. That is, when there is no preceding vehicle suitable for the following running, the cruise control that maintains the preset vehicle speed may be executed.
[0034]
Further, in the above embodiment, the case where the feedback formula of the formula (2) and the feedback formula of the inter-vehicle distance of the formula (3) are set to the P control is described next, but the present invention is not limited to this. That is, PD control or PID control may be applied.
In the above embodiment, the target inter-vehicle distance D^*Is calculated, and the target inter-vehicle distance D^*And the actual inter-vehicle distance D, the final target acceleration / deceleration G^*Has been described, but the present invention is not limited to this. That is, based on the inter-vehicle distance D, the host vehicle is determined to be L of the preceding vehicle.₀Time to reach the rear (inter-vehicle time) T₀Target vehicle speed V so that^*Is determined, and an engine output command value α is calculated based on a deviation ΔV between this and the actual vehicle speed V. When the engine output command value α is positive, the engine is controlled based on the calculated engine output command value α to be in an acceleration state. On the other hand, when it is negative, the target braking pressure may be set by PD control or PID control based on the vehicle speed deviation ΔV.
[0035]
Furthermore, in the above embodiment, the case where the alarm circuit 21 is configured by a buzzer has been described, but the present invention is not limited to this. That is, an alarm may be issued by using a display device such as a light-emitting diode to continuously light or blink it.
Further, in the above-described embodiment, the case where the own vehicle speed V is calculated by the average value of the wheel speeds of the driven wheels has been described, but the present invention is not limited to this. That is, the vehicle speed may be calculated by detecting the number of revolutions on the output side of the automatic transmission 3 or a vehicle speed calculating means used in the antilock brake control device may be applied.
[0036]
Furthermore, in the above embodiment, the case where the automatic transmission 3 is provided on the output side of the engine 2 has been described. However, the present invention is not limited to this, and a continuously variable transmission can be applied.
Further, in the above embodiment, the case where the present invention is applied to the rear wheel drive vehicle has been described, but the present invention is not limited to this. That is, the present invention can be applied to a front wheel drive vehicle. Further, the present invention can be applied to an electric vehicle using an electric motor instead of the engine, or a hybrid vehicle using both the engine and the electric motor. Incidentally, in this case, the engine output control device may be replaced with an electric motor control device.
[0037]
As described above, according to the embodiment, when the preceding vehicle detected by the inter-vehicle distance sensor 12 no longer exists, the following running control is immediately released. Is able to reliably prevent the braking force from remaining even though the vehicle is able to accelerate by leaving the front of the host vehicle and prevent the driver from feeling uncomfortable. Can be
[0038]
Next, a second embodiment of the present invention will be described with reference to FIGS.
In the second embodiment, when the release of the following travel control is accelerated due to the absence of the preceding vehicle, the release of the following travel control is accelerated as the deceleration of the own vehicle is smaller.
That is, in the second embodiment, as shown in FIG. 8, the control release process follows the same processing procedure as that of the first embodiment except that the processes of steps S41 and S42 are added. Parts corresponding to those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0039]
In step S41 to which the process proceeds when it is determined that the preceding vehicle is no longer present in the process of step S24, the deceleration α of the own vehicle is calculated. Here, when the deceleration α of the own vehicle is larger than the deceleration caused by the rolling resistance or the air resistance, the deceleration α is substantially equal to the target acceleration / deceleration G for control release._OFF ^*Is proportional to the magnitude of the braking force according to. Therefore, the deceleration α is changed, for example, to the target acceleration / deceleration G for control release calculated in the previous process._OFF ^*Calculated from That is, assuming that the proportional constant is k, the deceleration α can be calculated based on the following equation (5). Note that the processing in step S41 corresponds to deceleration calculation means.
[0040]
α = k × G_OFF ^*・ ・ ・ ・ ・ ・ (5)
Next, at step S42 to which the control proceeds, the target acceleration / deceleration G for control release is set such that the smaller the deceleration α calculated at step S41, the earlier the release of the following travel control._OFF ^*Is calculated.
First, the smaller the deceleration α, the smaller the target acceleration / deceleration G for control release._OFF ^*Control release target acceleration / deceleration G corresponding to the deceleration α so that_OFF ^*Of change ΔG_OFF ^*Is calculated. This change ΔG_OFF ^*Is calculated from the deceleration α with reference to the acceleration / deceleration change amount control map stored in advance in the memory of the travel control controller 20. As shown in FIG. 9, the acceleration / deceleration change rate calculation control map includes a deceleration α on the horizontal axis and a deceleration change amount ΔG on the vertical axis._OFF ^*When the deceleration α increases, the deceleration change amount ΔG_OFF ^*Is initially set to decrease steeply and gradually in a non-linear manner that gradually decreases.
[0041]
This deceleration change amount ΔG_OFF ^*To the previous target acceleration / deceleration G for control release._OFF ^* _(N-1)Is added to the target acceleration / deceleration G for control release in which the rate of change is adjusted according to the deceleration α._OFF ^* _(N)Can be calculated, and then the process proceeds to step S28.
Therefore, it is assumed that, for example, the preceding vehicle has departed from the front of the own vehicle during the cancellation of the following travel control (the determination in step S21 is "No"). At this time, as described above, the cancellation of the follow-up traveling is advanced so that the vehicle can immediately shift to the acceleration traveling. However, at this time t₅When the deceleration α is relatively large, the control target acceleration / deceleration G_OFF ^*If is immediately set to "0", the braking force suddenly disappears, giving the driver the feeling of being pushed out.
[0042]
Therefore, if the deceleration α of the own vehicle is large, the target acceleration / deceleration G_OFF ^*When the deceleration α is small, on the other hand, if the deceleration α is small, the target acceleration / deceleration G for control release is released in order to quickly release the following travel control._OFF ^*A larger amount of change is allowed. That is, the target acceleration / deceleration G for control release determined according to the deceleration α of the host vehicle_OFF ^*Of change ΔG_OFF ^*And the acceleration / deceleration change amount ΔG_OFF ^*Is the negative control release target acceleration / deceleration G calculated in the previous process._OFF ^* _(N-1)To the current target acceleration / deceleration G for control release._OFF ^* _(N)Is calculated. Therefore, as shown in FIG. 10, the time t when the preceding vehicle leaves the front of the host vehicle.₅From the final target acceleration / deceleration G^*Initially, it changes relatively slowly, and as the value decreases, it changes sharply, so that the driver does not feel as if the vehicle is suddenly pushed out, and furthermore, this follow-up driving control Release can be expedited.
[0043]
In the above embodiment, the deceleration α is set to the target acceleration / deceleration G for control release._OFF ^*Has been described, but the present invention is not limited to this. That is, an acceleration sensor may be provided to actually measure the deceleration α, or the deceleration α may be calculated from the braking oil pressure, the braking pressure command value, and the rate of change of the vehicle speed V.
Further, in the acceleration / deceleration change amount calculation control map of the above embodiment, when the deceleration α increases, the acceleration / deceleration change amount ΔG_OFF ^*Is described in a curved line, but the present invention is not limited to this, and the acceleration / deceleration change amount ΔG_OFF ^*May be used such that the control map decreases linearly.
[0044]
In the above embodiment, the target acceleration / deceleration G for control release is set according to the deceleration α of the host vehicle._OFF ^*Although the configuration for suppressing the change amount of the above has been described, the present invention is not limited to this. That is, for example, the target braking pressure P input to the braking control device 8_BMay be suppressed. In this case, similarly to the control map for calculating the acceleration / deceleration change amount described above, when the deceleration α increases, the braking pressure change amount ΔP_BWith reference to the control map for calculating the amount of change in braking pressure such that the value of_BAnd the braking pressure change amount ΔP_BIs the target braking pressure P output in the previous processing stage._BTo the target braking pressure P_BMay be calculated. The point is that when the deceleration α of the host vehicle is large, it is only necessary to suppress the sudden change in the vehicle speed and to quickly cancel the following traveling control.
[0045]
As described above, according to the embodiment, when the preceding vehicle is no longer present, the smaller the deceleration of the own vehicle, the earlier the release of the follow-up traveling control. Despite being able to move to accelerated driving by leaving from the front of the host vehicle, the braking force is reliably suppressed from remaining, and the vehicle seems to be pushed out due to the sudden disappearance of the braking force. Is not given to the driver.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram according to the present invention.
FIG. 2 is a flowchart illustrating an example of a traveling control process.
FIG. 3 is a flowchart illustrating an example of a control release process according to the first embodiment.
FIG. 4 is a control map for calculating a target braking pressure.
FIG. 5 is a time chart illustrating the operation of the first embodiment.
FIG. 6 is a time chart showing a conventional problem.
FIG. 7 is a time chart showing an operation when the preceding vehicle leaves in the first embodiment.
FIG. 8 is a flowchart illustrating an example of a control release process according to the second embodiment.
FIG. 9 is a control map for calculating an acceleration / deceleration change amount.
FIG. 10 is a time chart showing the operation in the second embodiment.
[Explanation of symbols]
1FL, 1FR front wheel
1RL, 1RR @ rear wheel
2 engine
3 automatic transmission
7 Disc brake device
8. Braking control device
9 Engine output control device
10 transmission control device
12 Inter-vehicle distance sensor (inter-vehicle distance detection means)
13L, 13R Wheel speed sensor
20 travel controller
21 Alarm circuit

Claims (3)

An inter-vehicle distance detecting means for detecting an inter-vehicle distance with a preceding vehicle, a vehicle speed detecting means for detecting a vehicle speed of the own vehicle, and a target acceleration / deceleration such that the inter-vehicle distance detected by the inter-vehicle distance detecting means matches the target inter-vehicle distance. Target acceleration / deceleration setting means to be set, traveling control means for controlling traveling to achieve the target acceleration / deceleration set by the target acceleration / deceleration setting means, and detection by the vehicle speed detection means during deceleration control by the traveling control means Running control canceling means for canceling running control by the running control means when the vehicle speed becomes equal to or less than a set vehicle speed,
The travel canceling means cancels the travel control by the travel control means so that the acceleration change becomes gentle, while maintaining the detection of the preceding vehicle by the inter-vehicle distance detection means, and detects the detection by the inter-vehicle distance detection means. A travel control device for a vehicle, wherein when the target preceding vehicle no longer exists, the release of the travel control by the travel control means is hastened. 2. The inter-vehicle distance according to claim 1, wherein the running control canceling unit immediately cancels the running control by the running control unit when the preceding vehicle detected by the inter-vehicle distance detecting unit no longer exists. 3. Control device. Deceleration calculating means for calculating the deceleration of the own vehicle, wherein the travel control canceling means calculates the deceleration calculating means when the preceding vehicle to be detected by the inter-vehicle distance detecting means no longer exists. 2. The vehicle travel control device according to claim 1, wherein as the degree of deceleration of the own vehicle is smaller, release of the travel control by the travel unit is hastened. 3.

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