JP4039364B2 - Prior vehicle following travel control device - Google Patents

Description

  The present invention relates to a preceding vehicle following traveling control device that controls the traveling state of a host vehicle so as to follow a preceding vehicle.

As a conventional preceding vehicle following travel control device, for example, there is a device disclosed in Patent Document 1. The preceding vehicle follow-up travel control device disclosed in Patent Document 1 limits the acceleration command value with the first acceleration command upper limit value selected to be smaller than the normal acceleration command upper limit value when the follow-up running control is started. When the limited state continues the state where the actual acceleration exceeds the first control threshold for the first duration or longer, the acceleration command value is limited by a second acceleration command upper limit value higher than the first acceleration command upper limit value, When this limited state continues for a second duration or longer when the actual acceleration exceeds the second control threshold, acceleration is performed at a third acceleration command upper limit value that is higher than the second acceleration command upper limit value and close to the normal acceleration command upper limit value. The command value is limited so that the acceleration at the start of the follow-up running is controlled to increase gently.
Japanese Patent Laid-Open No. 2002-127782

If the follow-up driving control intervenes while the driver is accelerating the host vehicle by operating the accelerator pedal, the host vehicle may be accelerated within the acceleration command upper limit value different from the acceleration by the driver. Become. In this case, acceleration different from the driver's intention to accelerate is exhibited, and depending on the driving scene, the acceleration is unexpected for the driver.
Also, if the driver steps on the accelerator and tries to catch up with the preceding vehicle and then releases the accelerator, the follow-up running control may intervene, but if the acceleration command upper limit is smaller than the acceleration immediately before the control intervention, There is a possibility that the vehicle is left on the preceding vehicle.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a preceding vehicle follow-up travel control device that can accelerate without causing the driver to feel uncomfortable when the follow-up travel control is started.

In the preceding vehicle follow-up travel control device according to the first aspect of the invention, when the follow-up running control for running so as to follow the preceding vehicle is started, the control acceleration of the follow-up running control is set to the target travel vehicle speed and the actual vehicle speed. This is a preceding vehicle follow-up travel control device that sets the target acceleration calculated based on the difference between the two and performs the follow-up travel control. When the acceleration based on the driver's intention to accelerate before the start of the following traveling control is greater than the target acceleration, the preceding vehicle following travel control device changes the control acceleration to an acceleration based on the driver's intention to accelerate. Then, the follow-up running control is started.

The preceding vehicle follow-up travel control device according to the invention described in claim 2 is configured such that when the follow-up running control for running so as to follow the preceding vehicle is started , the control acceleration of the follow-up running control is set to the target running vehicle speed and the actual vehicle. This is a preceding vehicle follow-up travel control device that sets the target acceleration calculated based on the difference from the speed and performs the follow-up travel control. The preceding vehicle follow-up travel control device detects an inter-vehicle distance between the host vehicle and the preceding vehicle by an inter-vehicle distance detection means, and detects an acceleration based on a driver's intention to accelerate before the follow-up running control is started. The acceleration based on the driver's intention to accelerate detected by the driver intention acceleration detection means and the target acceleration are compared by the acceleration comparison means, and the comparison result of the acceleration comparison means is the acceleration of the driver. When the acceleration based on the intention is greater than the target acceleration , and the inter-vehicle distance detected by the inter-vehicle distance detection means is greater than a predetermined inter-vehicle distance, the target acceleration is changed to an acceleration based on the driver's acceleration intention Then, the following traveling control is started by the traveling control means.

According to the present invention, when the acceleration based on the driver's acceleration intention before the start of the tracking control is larger than the predetermined acceleration, the tracking control is performed with the acceleration based on the driver's acceleration intention. Follow-up running control can be started with an acceleration that is not given.
According to the second aspect of the invention, when the inter-vehicle distance is larger than the predetermined inter-vehicle distance, the follow-up running control is performed with the acceleration based on the driver's acceleration intention. The follow-up running control can be performed.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
FIG. 1 is a system configuration diagram showing an embodiment of a vehicle with a preceding vehicle follow-up travel control device to which the present invention is applied. This vehicle is a rear wheel drive vehicle in which the rear wheels 1RL and 1RR are driving wheels and the front wheels 1FL and 1FR are driven wheels, and the driving torque of the engine 2 is transmitted to the rear wheels 1RL and 1RR via the automatic transmission 3. Is done.

The rotation state, torque, output, etc. of the engine 2 can be controlled by the engine control device 11. Specifically, the engine rotation state, torque, output, etc. can be controlled by adjusting the throttle valve opening, idle valve opening, ignition timing, fuel injection amount, fuel injection timing, and the like.
The automatic transmission 3 can be controlled by a transmission control device 12. Specifically, by adjusting the working fluid pressure supplied to the clutch and brake in the automatic transmission 3, the selected gear ratio can be changed to obtain a desired reduction ratio.

  The wheels 1FL to 1RR are provided with wheel cylinders 4FL to 4RR constituting so-called disc brakes. The wheel cylinders 4FL to 4RR apply a braking force to the wheels 1FL to 1RR by the supplied brake fluid pressure. The braking force applied to each of the wheels 1FL to 1RR can be controlled by the braking fluid pressure control device 13. Specifically, for example, each wheel cylinder 4FL˜ is increased by increasing the brake fluid pressure as in the driving force control device (TCS) or decreasing the brake fluid pressure as in the anti-skid control device (ABS). The braking fluid pressure to 4RR can be adjusted and the braking force to each wheel 1FL-1RR can be controlled. The braking fluid pressure regulated in the braking fluid pressure control device 13 is supplied from a master cylinder 22 that is boosted by depressing the brake pedal 21.

Each of these control devices controls the running state of the vehicle, and as a result, the running state can be controlled by adjusting the acceleration / deceleration, the longitudinal speed, etc. of the host vehicle.
Of course, these control devices can operate alone, but the overall function is governed by the automatic travel control device 10 including inter-vehicle distance control and preceding vehicle following travel control. The automatic travel control device 10 performs various arithmetic processes to control the travel state of the vehicle, thereby performing inter-vehicle distance control, preceding vehicle following travel control, and the like.

  Further, the vehicle is provided with a CCD camera or the like, for example, a front state detection device 16 for detecting a state in front of the host vehicle, for example, a state of a traveling lane, presence or absence of a preceding vehicle, or a distance to the preceding vehicle, or each wheel 1FL A wheel speed sensor 17 for detecting a rotational speed of ˜1RR, an acceleration sensor 18 for detecting longitudinal and lateral accelerations generated in the vehicle, a brake fluid pressure sensor 19 for detecting a brake fluid pressure, and an accelerator opening for detecting an accelerator pedal depression amount A degree sensor 20 is provided. Further, this vehicle is provided with a manual switch 9 for adjusting the traveling state of the host vehicle by a driver's manual input.

Further, this vehicle is provided with a navigation system 7 that detects the position information of the own vehicle by so-called GPS (Global Positioning System). Further, the vehicle is provided with a display and a speaker 23 for presenting the contents of control by the automatic travel control device 10 to an occupant, particularly a driver.
In addition, the vehicle, specifically the steering wheel, is provided with a manual switch 9 for adjusting the traveling state of the host vehicle by a driver's manual input. Details of the manual switch 9 are shown in FIG. In the figure, reference numeral 9a is a start switch for travel control including preceding vehicle follow-up travel control, 9b is a travel control release switch, 9c is a set inter-vehicle distance switch for inputting a set inter-vehicle distance, 9d is an input for a set travel speed, A set / coast switch 9e for changing the set travel speed in the deceleration direction is a resume / accelerate switch for re-inputting the previous set travel speed or changing the set travel speed in the acceleration direction after canceling the travel control.

  Of these, the set inter-vehicle distance switch 9c is not used to input a specific set inter-vehicle distance as a numerical value. For example, the set inter-vehicle distance switch 9c is used to increase or decrease the current inter-vehicle distance. In contrast, when the most standard target inter-vehicle distance is set to “medium”, an input method such as “long” for increasing the set inter-vehicle distance or “short” for decreasing the set inter-vehicle distance is adopted. .

The functions of the resume / accelerate switch 9e and the set / coast switch 9d will be described below.
If the resume / accelerate switch 9e is pressed when the start switch 9a is ON and the vehicle speed of the host vehicle is 30-100 km / h, the set travel speed of constant vehicle speed travel control (hereinafter also referred to as ASCD control) is set at that time. And the high-speed preceding vehicle following traveling control (hereinafter also referred to as ACC control) for following the preceding vehicle with the set traveling speed as the upper limit vehicle speed. The ACC control performs control to follow the preceding vehicle when the front state detection device 16 detects the preceding vehicle, and performs ASCD control when the front state detection device 16 cannot detect the preceding vehicle. It is also possible to set to a mode in which only the ASCD control is performed by the driver's setting.

  If the set / coast switch 9d is pressed when the start switch 9a is ON and the vehicle speed of the host vehicle is 30 to 100 km / h, the set traveling speed of the ASCD control is reset to the previously set vehicle speed. The ACC control is started with the set travel speed as the upper limit vehicle speed. The speed range to be controlled by the ACC control and the set traveling speed of the ASCD are 30 to 100 km / h, and the ACC control is canceled when the host vehicle speed becomes 30 km / h or less.

  Also, if the resume / accelerate switch 9e (or the set / coast switch 9d) is pressed when the start switch 9a is ON and the vehicle speed of the host vehicle is 0 to 30 km / h, the low-speed preceding vehicle following that follows the preceding vehicle is performed. Travel control (hereinafter also referred to as inching control) is started. Note that the speed range to be controlled by inching control is 0 to 45 km / h, and overlaps with the vehicle speed range of the previous ACC control between 30 and 45 km / h.

Inching control performs control to follow the preceding vehicle only when the front state detection device 16 detects the preceding vehicle, and the control is performed when the preceding vehicle cannot be detected and when the vehicle speed exceeds 45 km / h. Canceled.
In order to shift from the ACC control to the inching control, it is necessary to press the set / coast switch 9d in this overlapping region (30 to 45 km / h). Further, in order to shift from inching control to ACC control, it is necessary to press the resume / accelerate switch 9e in this overlapping region.

  Next, calculation processing of the inter-vehicle distance control performed in the automatic travel control device 10 will be described with reference to the flowchart of FIG. This calculation process is executed by a timer interrupt every predetermined sampling time ΔT set to, for example, about 10 msec. In this flowchart, no particular communication step is provided, but the results obtained by the arithmetic processing are updated and stored in the storage device as needed, and necessary information and programs are read from the storage device as needed. Further, the above-described engine control device 11, transmission control device 12, and brake fluid pressure control device 13 communicate with each other at any time, and necessary information and commands are exchanged bidirectionally at any time.

In this calculation processing, first, in step S1, the longitudinal acceleration Xg and lateral acceleration Yg detected by the acceleration sensor 18, the wheel speed Vw _j (j = FL to RR) detected by the wheel speed sensor 17, the accelerator opening. The accelerator opening degree Acc detected by the degree sensor 20, the braking fluid pressure Pm detected by the braking fluid pressure sensor 19, the set traveling speed Vc set by the manual switch 9, and the forward state detecting device 16 The distance d between the preceding vehicle and the engine driving torque Tw controlled by the engine control device 11 is read.

Subsequently, in step S2, the traveling speed V of the host vehicle is calculated from the average values of the front left and right wheel speeds Vw _FL and Vw _FR among the wheel speeds Vwj read in step S1.
Subsequently, in step S3, the difference value between the current value d _(n) and the previous value d _(n-1) of the inter-vehicle distance read in step S1 is divided by the predetermined sampling time ΔT, A relative speed Vr between the host vehicle and the preceding vehicle is calculated.
Subsequently, in step S4, a target inter-vehicle distance dr corresponding to the traveling speed V of the host vehicle calculated in step S2 is calculated. Specifically, the travel speed V of the host vehicle is multiplied by a predetermined control gain, and a predetermined control constant is summed. The control gain and the control constant are set in accordance with the set inter-vehicle distance requested by the driver inputted by the set inter-vehicle distance switch 9c of the manual switch 9.

Subsequently, in step S5, a target travel speed Vs is calculated. Specifically, the target travel speed Vs is calculated as follows.
First, the value obtained by multiplying the difference value between the target inter-vehicle distance dr calculated in step S4 and the actual inter-vehicle distance d read in step S1 by the proportional control gain, and the relative speed Vr calculated in step S3 are differentiated. The reference target travel speed Vso is calculated from an addition value with the value multiplied by the control gain. Then, the smaller one of the calculated reference target travel speed Vso and the set travel speed Vc read in step S1 is set as the target travel speed Vs.

Subsequently, in step S6, from the difference value between the target traveling speed Vs calculated in step S5 and the traveling speed V of the host vehicle calculated in step S2, the target acceleration a _c by, for example, PID (proportional-differential-integral) control is performed. Is calculated.
Subsequently, in step S20, a control acceleration Vgs is calculated. Control acceleration Vgs is a predetermined processing, is set to the latest of the longitudinal acceleration Xg read in the target acceleration a _c and the step S1 calculated at step S6. A procedure for calculating (setting) the control acceleration Vgs will be described later.

Subsequently, in step S7, for example, when the control acceleration Vgs calculated in step S20 is negative, that is, when deceleration is required, a value obtained by multiplying the control acceleration Vgs by a brake specification coefficient, and in step S1. Of the value obtained by multiplying the read brake fluid pressure Pm by the brake specification coefficient, the larger one is calculated as the target brake fluid pressure Pws _j . The brake specification coefficient is a coefficient determined by, for example, the friction coefficient between the disk rotor pads of each wheel, the wheel cylinder cross-sectional area, the disk rotor effective diameter, the tire rolling radius, and the like.

  Subsequently, in step S8, when the control acceleration Vgs calculated in step S20 is positive, that is, when acceleration is required, a value obtained by multiplying the control acceleration Vgs by a drive system variable, and in step S1. Of the values obtained by multiplying the read accelerator opening degree Acc by the drive system specification variable, the larger one is calculated as the target drive torque Tes. The drive system specification variable is a variable determined by, for example, gear inertia, reduction ratio, transmission efficiency, engine characteristics, and the like.

Subsequently, in step S9, the target braking fluid pressure Pws _j calculated in step S7 and the target driving torque Tes calculated in step S8 are directed to the braking fluid pressure control device 13, the engine control device 11, and the transmission control device 12. Output. Further, the information presenting signal for the target inter-vehicle distance control is output to the display and the speaker 23, and then the process returns to the main program. For example, when the target distance between the vehicles is changed and controlled, for example, content such as “increase the distance between vehicles” is presented by voice or display before the information is presented by the display and the speaker 23.

According to this calculation process, the target travel speed Vs is set by the reference target travel speed Vso obtained based on the set travel speed Vc set by the manual switch 9 or the target inter-vehicle distance dr (steps S4 and S5). Then, the target acceleration _ac is calculated from the difference between the set target traveling speed Vs and the traveling speed V of the host vehicle (step S6), and the target braking fluid is set so as to be the target acceleration _ac or the latest longitudinal acceleration Xg. The pressure Pws _j and the target drive torque Tes are output to the brake fluid pressure control device 13, the engine control device 11, and the transmission control device 12, and an information presentation signal for target inter-vehicle distance control is directed to the display and the speaker 23. (Step S7, Step S8, Step S9).

Next, the calculation procedure of the control acceleration Vgs in step 20 in the calculation process of FIG. 3 will be described. FIG. 4 shows a calculation processing procedure for the control acceleration Vgs.
First, in step 21, it is determined whether or not the control operation determination flag FLAG_A is 1 or 2. This control operation determination flag FLAG_A has an initial value of 2. When the control operation determination flag FLAG_A is 1 or 2 (FLAG_A = 1 or FLAG_A = 2), the process proceeds to step S22. When the control operation determination flag FLAG_A is 1 or not 2, specifically, the control operation determination flag FLAG_A Is 0 (FLAG_A = 0), the process proceeds to step S29.

  In step S22, it is determined whether or not the accelerator pedal is ON (the accelerator is open) when the set / coast switch 9d for executing the low-speed preceding vehicle following traveling control is pressed. That is, the driver's intention to accelerate at the start of the low-speed preceding vehicle following travel control is determined. Here, if the accelerator pedal is ON when the set / coast switch 9d is pressed, the process proceeds to step S23, and if the accelerator pedal is not ON when the set / coast switch 9d is pressed, Alternatively, if the set / coast switch 9d has not been pressed, the process proceeds to step S24.

In step S23, the control operation determination flag FLAG_A is set to 1, and the temporary acceleration Apr is set to the longitudinal acceleration Xg read in step S1. The longitudinal acceleration Xg is specifically the longitudinal acceleration Xg immediately before the start of the low-speed preceding vehicle following traveling control. Then, the process proceeds to step S24.
In step S24, it is determined whether or not the control operation determination flag FLAG_A is 1. Here, when the control operation determination flag FLAG_A is 1 (FLAG_A = 1), the process proceeds to step S25. When the control operation determination flag FLAG_A is not 1, specifically, the control operation determination flag FLAG_A is 0 or 2. In the case (FLAG_A = 0 or FLAG_A = 2), the process proceeds to step S30.

At step S25, it determines temporary acceleration Apr whether less than the target acceleration _{a c} calculated in step S6. Here, when the temporary acceleration Apr is less than the target acceleration _{a c (Apr <a c)} , the process proceeds to step S28, when the temporary acceleration Apr is above the target acceleration _{a c (Apr ≧ a c)} , the process proceeds to step S26.
In step S26, it is determined whether or not the actual inter-vehicle distance d read in step S1 is larger than the target inter-vehicle distance dr calculated in step S4. If the inter-vehicle distance d is greater than the target inter-vehicle distance dr (d> dr), the process proceeds to step S27. If the inter-vehicle distance d is equal to or less than the target inter-vehicle distance dr (d ≦ dr), the process proceeds to step S30.

In step S27, the control acceleration Vgs is set to the temporary acceleration Apr, that is, the longitudinal acceleration Xg immediately before the start of the low-speed preceding vehicle following traveling control. Then, the processing from step S21 is performed again.
Also, temporary acceleration Apr in step S25 is the step S28 proceeds to the case of less than the target acceleration _{a c,} sets the control acceleration Vgs to the target acceleration _{a c.} Then, the processing from step S21 is performed again.

Further, in step S30 that proceeds when the control operation determination flag FLAG_A is not 1 in step S24 or when the inter-vehicle distance d is equal to or less than the target inter-vehicle distance dr in step S26, the control acceleration Vgs is set to the current longitudinal acceleration Xg. Then, the process proceeds to step S31.
Further, in step S29 which proceeds when the control operation determination flag FLAG_A is 0 in step S21, whether or not the actual inter-vehicle distance d read in step S1 is larger than the target inter-vehicle distance dr calculated in step S4. Determine. If the inter-vehicle distance d is greater than the target inter-vehicle distance dr (d> dr), the process proceeds to step S22. If the inter-vehicle distance d is equal to or less than the target inter-vehicle distance dr (d ≦ dr), the process proceeds to step S31.

The step S31 is a step that proceeds even when the control operation determination flag FLAG_A is 0 or 2 in the step S24 or when the inter-vehicle distance d is equal to or less than the target inter-vehicle distance dr in the step S26.
In step S31, the control operation determination flag FLAG_A is set to 0.
Subsequently, in Step S32, determines control acceleration Vgs is whether less than the target acceleration _{a c.} Here, if the control acceleration Vgs is less than the target acceleration _{a c (Vgs <a c)} , the process proceeds to step S33, if the control acceleration Vgs is equal to or greater than the target acceleration _{a c (Vgs ≧ a c)} , the process proceeds to step S36.

In step S33, a step amount α is added to the control acceleration Vgs to obtain a new control acceleration Vgs. Here, the step amount α is a step amount for acceleration, and is a value determined according to a processing speed in a processing apparatus such as a microcomputer.
Subsequently, in step S34, it determines whether or not the control acceleration Vgs is greater than the target acceleration _{a c.} Here, if the control acceleration Vgs is greater than the target acceleration _{a c (Vgs> a c)} , the process proceeds to step S34, if the control acceleration Vgs is below the target acceleration _{a c (Vgs ≦ a c)} , from the step S21 again Perform the process.

In step S35, it sets the control acceleration Vgs to the target acceleration _{a c.} Then, the processing from step S21 is performed again.
Further, in step S36 the control acceleration Vgs at the step S32 proceeds to the case of more than the target acceleration _{a c,} by subtracting the step amount α from the control acceleration Vgs, obtain a new control acceleration Vgs. Here, the step amount α is a step amount for decelerating, and is a value determined according to a processing speed in a processing apparatus such as a microcomputer.

Subsequently, in step S37, determines control acceleration Vgs is whether less than the target acceleration _{a c.} Here, if the control acceleration Vgs is less than the target acceleration _{a c (Vgs <a c)} , the process proceeds to step S38, the case control acceleration Vgs is equal to or greater than the target acceleration _{a c (Vgs ≧ a c)} , from the step S21 again Process.
At step S38, the setting control acceleration Vgs to the target acceleration _{a c.} Then, the processing from step S21 is performed again.

According to this processing, a set / when coasting accelerator pedal when the switch 9d is depressed was turned ON, and when the temporary acceleration Apr (current longitudinal acceleration Xg) is equal to or greater than the target acceleration a _c, If the inter-vehicle distance d is greater than the target inter-vehicle distance dr, the control acceleration Vgs is set to the temporary acceleration Apr, that is, the longitudinal acceleration Xg immediately before the start of the low-speed preceding vehicle following travel control (step S27).
Although the accelerator pedal is ON when the set / coast switch 9d is depressed, when the temporary acceleration Apr (longitudinal acceleration Xg of the low speed preceding vehicle following cruise control immediately before the start) is less than the target acceleration a _c is sets control acceleration Vgs to the target acceleration _{a c} (step S28).

Further, when the set / coast switch 9d is pressed but the accelerator pedal is not turned on, or when the set / coast switch 9d is not pressed, the control acceleration Vgs is changed before and after the start of the low-speed preceding vehicle following travel control. The acceleration Xg is set, and the processing from step S31 is performed (step S24, step S30, step S31). Also, the set / coast when the accelerator pedal when the switch 9d is depressed was turned ON, and when the temporary acceleration Apr (longitudinal acceleration Xg of the low speed preceding vehicle following cruise control immediately before the start) is equal to or greater than the target acceleration a _c However, when the inter-vehicle distance d is equal to or less than the target inter-vehicle distance dr, the control acceleration Vgs is set to the longitudinal acceleration Xg immediately before the start of the low-speed preceding vehicle following travel control, and the processing from step S31 is performed (step S26, step S26). S30, step S31). If the control operation determination flag FLAG_A is 0 and the inter-vehicle distance d is equal to or less than the target inter-vehicle distance dr, the processing from step S31 is performed (steps S21, S29, and S31). In step S31, the control operation determination flag FLAG_A is set to 0.

Then, in subsequent step S32 subsequent seeking magnitude relationship between the control acceleration Vgs and the target acceleration a _c, it performs processing to asymptotic control acceleration Vgs to the target acceleration a _c.
That is, the control when the acceleration Vgs is less than the target acceleration _{a c,} control the acceleration Vgs step amount α to calculate a new control acceleration Vgs obtained by adding to (the step S32, step S33), control the acceleration Vgs is the target acceleration and the calculated When it becomes larger than _ac , the target acceleration _ac is set to the control acceleration Vgs (steps S34 and S35). And the process from step S21 is performed again.

The control acceleration when Vgs is greater than the target acceleration _{a c,} control the acceleration Vgs step amount α to calculate a new control acceleration Vgs subtracted from (the step S32, step S36), control the acceleration Vgs is the target acceleration and the calculated When it becomes less than _ac , the target acceleration _ac is set to the control acceleration Vgs (steps S37 and S38). And the process from step S21 is performed again.

When the processing after step S32 is started, the control operation determination flag FLAG_A is set to 0 (step S31). Therefore, even when the processing from step S21 is performed, the inter-vehicle distance d is the target inter-vehicle distance dr. As long as the following is true, the processing after step S32 is performed at predetermined time intervals (steps S21 and S29). Thus, the control acceleration Vgs is of less than the target acceleration _{a c,} control the acceleration Vgs until the target acceleration _{a c} is so increased by the step amount alpha (step S32~ step S35). Further, if the control acceleration Vgs is equal to or greater than the target acceleration _{a c,} the target acceleration _a controlled acceleration Vgs until _c is to reduce by steps the amount of alpha (step S32, step S36~ step S38). That is, the control when the acceleration Vgs is less than the target acceleration a _c, control the acceleration Vgs increases by asymptotic to a target acceleration a _c, control when the acceleration Vgs is equal to or greater than the target acceleration a _c, reduced allowed by the target acceleration control acceleration Vgs Asymptotically approach a _c .

Thus, the set / coast when the accelerator pedal when the switch 9d is depressed was turned ON, and when the temporary acceleration Apr (longitudinal acceleration Xg of the low speed preceding vehicle following cruise control immediately before the start) is equal to or greater than the target acceleration a _c But, when the inter-vehicle distance d is equal to or less than the target inter-vehicle distance dr when control acceleration Vgs is longitudinal acceleration Xg of the low speed preceding vehicle following cruise control immediately before is less than the target acceleration a _c, increasing the control acceleration Vgs to target it is asymptotic to the acceleration a _c, when the control acceleration Vgs is longitudinal acceleration Xg of the low speed preceding vehicle following cruise control immediately before is not less than the target acceleration a _c, reduces the control acceleration Vgs is asymptotic to a target acceleration a _c.

The same control acceleration Vgs is also adjusted when the set / coast switch 9d is pressed but the accelerator pedal is not ON, or when the set / coast switch 9d is not pressed. That is, when the control acceleration Vgs is longitudinal acceleration Xg of the low speed preceding vehicle following cruise control immediately before is less than the target acceleration a _c, thereby increasing the control acceleration Vgs is asymptotic to a target acceleration a _c, slow the preceding vehicle following cruise control start If the control acceleration Vgs is longitudinal acceleration Xg just before is not less than the target acceleration a _c, reduces the control acceleration Vgs is asymptotic to a target acceleration a _c.

Also, the set / coast when the accelerator pedal when the switch 9d is depressed was turned ON, and when the temporary acceleration Apr (longitudinal acceleration Xg of the low speed preceding vehicle following cruise control immediately before the start) is equal to or greater than the target acceleration a _c However, when the inter-vehicle distance d is equal to or less than the target inter-vehicle distance dr, the same control acceleration Vgs is adjusted. That is, when the control acceleration Vgs is longitudinal acceleration Xg of the low speed preceding vehicle following cruise control immediately before is less than the target acceleration a _c, thereby increasing the control acceleration Vgs is asymptotic to a target acceleration a _c, slow the preceding vehicle following cruise control start If the control acceleration Vgs is longitudinal acceleration Xg just before is not less than the target acceleration a _c, reduces the control acceleration Vgs is asymptotic to a target acceleration a _c.

As described above, the processes after step S32 are continuously executed under various conditions. However, when the inter-vehicle distance d becomes larger than the target inter-vehicle distance dr, the processes after step S22 are started again. . That is, once again set / coast switch 9d, set the control acceleration Vgs in accordance with the accelerator pedal, the magnitude relationship and the inter-vehicle distance d between the temporary acceleration Apr (longitudinal acceleration Xg of the low speed preceding vehicle following cruise control immediately before the start) and the target acceleration a _c To do.

Then, the target braking fluid pressure Pws _j and the target driving torque Tes are set toward the braking fluid pressure control device 13, the engine control device 11, and the transmission control device 12 so that the control acceleration Vgs set by such calculation processing is obtained. Output (steps S8 and S9). As a result, the host vehicle after the start of the low-speed preceding vehicle following traveling control is accelerated according to the target acceleration _ac and the acceleration immediately before the start of the low-speed preceding vehicle following traveling control so as to follow the preceding vehicle. become.

FIG. 5 shows changes with time in vehicle speed or acceleration realized by this processing.
When the accelerator pedal is ON when the set / coast switch 9d is pressed, even when the low-speed preceding vehicle following traveling control is started at the point A in the figure, immediately before the low-speed preceding vehicle following traveling control is started. The host vehicle is accelerated by acceleration (control acceleration Vgs which is provisional acceleration Apr). When the inter-vehicle distance d becomes the target inter-vehicle distance dr (point B in the figure), the acceleration (the control acceleration Vgs that is the provisional acceleration Apr) is used as the target acceleration that is the original control target amount of the low-speed preceding vehicle following travel control. go to asymptotic to a _c. Specifically, when the vehicle acceleration (control acceleration Vgs) is less than the target acceleration a _c is the vehicle acceleration (control acceleration Vgs) is gradually increases so that the target acceleration a _c ( step S32~ step S35), when the vehicle acceleration (control acceleration Vgs) is equal to or greater than the target acceleration _{a c} is an acceleration (control acceleration Vgs of the vehicle) is gradually reduced so that the target acceleration _{a c} (Step S32, Step S36 to Step S38).

  As described above, when the accelerator pedal is ON when the low-speed preceding vehicle following traveling control is started, that is, when the driver intends to accelerate when starting the low-speed preceding vehicle following traveling control, the low-speed preceding vehicle following traveling control is started. The host vehicle under low-speed preceding vehicle following traveling control is accelerated with acceleration based on the driver's intention to accelerate immediately before. Then, the host vehicle is accelerated, and when the inter-vehicle distance with the preceding vehicle becomes smaller than the predetermined inter-vehicle distance, the host vehicle is accelerated with the original acceleration (predetermined acceleration) prepared in the low-speed preceding vehicle following traveling control. .

In the figure, the change over time of the vehicle speed or acceleration in the conventional control is shown as a constant chain line. As shown here, in the conventional control, even when the accelerator pedal is on when the set / coast switch 9d is pressed, that is, when the vehicle is accelerated by the driver's intention to accelerate, original acceleration of the low speed preceding vehicle following cruise control (predetermined acceleration, in this embodiment corresponds to a target acceleration a _c) accelerating the host vehicle. Thus, for example, when the original acceleration of the low-speed preceding vehicle following traveling control is smaller than the acceleration obtained by the driver pressing the accelerator pedal, when the low-speed preceding vehicle following traveling control is started (point A in the figure). ), The host vehicle exhibits a decelerating behavior against the driver's intention to accelerate.

On the other hand, in the present embodiment, even if the low-speed preceding vehicle following traveling control is started (point A in the figure), it is obtained by the driver's accelerator operation until just before the low-speed preceding vehicle following traveling control is started thereafter. The host vehicle is accelerated by the acceleration.
In addition, when the host vehicle is accelerated and the inter-vehicle distance from the preceding vehicle becomes smaller than the predetermined inter-vehicle distance, the host vehicle is accelerated at the original acceleration (predetermined acceleration) prepared by the low-speed preceding vehicle following traveling control. Thus, it is possible to prevent the host vehicle from being too close to the preceding vehicle.

The embodiment of the present invention has been described above. However, the present invention is not limited to being realized as the above-described embodiment.
That is, in the above-described embodiment, the case where the present invention is applied to the low-speed preceding vehicle following traveling control or inching control has been described. However, it is not limited to this. That is, the present invention can be applied as long as the preceding vehicle following traveling control is performed in which the following control is performed at a predetermined acceleration when the following traveling control is started.

  In the description of the above-described embodiment, the forward state detection device 16 realizes an inter-vehicle distance detection means for detecting the inter-vehicle distance between the host vehicle and the preceding vehicle, and step S22 of the automatic travel control device 10 in FIG. And the process of step S23 implement | achieves the driver | operator intention acceleration detection means which detects the acceleration based on a driver | operator's will of acceleration before the follow-up driving control start, and the process of step S25 in FIG. , An acceleration comparison means for comparing the acceleration based on the driver's intention of acceleration detected by the driver's intention acceleration detection means and the predetermined acceleration is realized. Step S25 in FIG. In the processing of S26 and step S27, the comparison result of the acceleration comparison means indicates that the acceleration based on the driver's acceleration intention is greater than the predetermined acceleration. If heard, and when the inter-vehicle distance detected by inter-vehicle distance detecting means is larger than a predetermined inter-vehicle distance, constitute a driving control means for performing the following cruise control in the acceleration based on the acceleration intention of the driver.

It is a vehicle block diagram which shows an example of the vehicle with a preceding vehicle following travel control apparatus of embodiment of this invention. It is a figure which shows the structure of the manual switch of FIG. It is a flowchart which shows the arithmetic processing for the inter-vehicle distance control performed with the automatic travel control apparatus of FIG. It is a flowchart which shows the arithmetic processing of the subroutine performed by the arithmetic processing of FIG. It is the figure used for description of the effect of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 FL-1RR is a wheel 2 Engine 3 Automatic transmission 4FL-4RR Wheel cylinder 7 Navigation system 9 Manual switch 10 Automatic travel control apparatus 11 Engine control apparatus 12 Transmission control apparatus 13 Braking fluid pressure control apparatus 16 Front state detection apparatus 17 Wheel Speed sensor 18 Acceleration sensor 19 Brake fluid pressure sensor 20 Accelerator opening sensor 21 Brake pedal 22 Master cylinder 23 Display and speaker

Claims (7)

When follow-up running control that runs to follow the preceding vehicle is started, the control acceleration of the follow-up running control is set to the target acceleration calculated based on the difference between the target running vehicle speed and the actual vehicle speed. In the preceding vehicle follow-up travel control device that performs travel control,
When the acceleration based on the driver's intention to accelerate before the start of the following traveling control is larger than the target acceleration , the control acceleration is changed to the acceleration based on the driver's intention to accelerate and the following traveling control is started. A preceding vehicle follow-up travel control device. When follow-up running control that runs to follow the preceding vehicle is started , the control acceleration of the follow-up running control is set to the target acceleration calculated based on the difference between the target running vehicle speed and the actual vehicle speed. In the preceding vehicle follow-up travel control device that performs travel control,
An inter-vehicle distance detecting means for detecting an inter-vehicle distance between the host vehicle and the preceding vehicle;
Driver intention acceleration detecting means for detecting acceleration based on the driver's acceleration intention before the start of the follow-up running control;
Acceleration comparison means for comparing the acceleration based on the driver's acceleration intention detected by the driver intention acceleration detection means and the target acceleration ;
When the comparison result of the acceleration comparison means indicates that the acceleration based on the driver's intention to accelerate is greater than the target acceleration , and the inter-vehicle distance detected by the inter-vehicle distance detection means is greater than a predetermined inter-vehicle distance, the control change the acceleration to the acceleration based on the acceleration intention of the driver, the traveling control means for starting the follow-up running control,
A preceding vehicle follow-up travel control device comprising: The travel control means performs the follow-up travel control at the target acceleration when the inter-vehicle distance detected by the inter-vehicle distance detection means during the follow-up travel control is equal to or less than the predetermined inter-vehicle distance. The preceding vehicle following travel control device according to claim 2. The travel control means gradually reduces the control acceleration changed to the acceleration based on the driver's intention to accelerate to the acceleration before the change with the lapse of time after the start of the follow-up travel control. The preceding vehicle following travel control device according to claim 3.   5. The advance according to claim 2, wherein the driver intention acceleration detection unit detects an acceleration based on the driver's acceleration intention based on a driver's accelerator operation. 6. Vehicle following travel control device.   6. The driver intention acceleration detecting means uses a longitudinal acceleration of the vehicle when accelerating by a driver's accelerator operation as an acceleration based on the driver's acceleration intention. The preceding vehicle following travel control device according to one item. When the driver stops the accelerator operation, the travel control means changes the control acceleration to an acceleration based on the driver's intention to accelerate immediately before the stop, and starts the follow-up travel control. The preceding vehicle following travel control device according to any one of claims 2 to 6.

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