JP2000006787A - Traveling controller for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit the starting of follow-up traveling control on a low friction coefficient road surface regarding a vehicle traveling controller performing follow-up traveling while keeping a distance from a vehicle traveling ahead. SOLUTION: For example, since a controller for traveling state control performs driving force control or the like on a low friction coefficient road surface, when a control state signal SS indicating on-going driving force control becomes equal to a logical value '1', traveling on the low friction coefficient road surface is determined by detecting this, an operation history flag FT is set to '1' (step S4, S5, S9 and S10), control is inhibited during on-going follow-up traveling control and, when the starting of follow-up traveling control is requested while a state is not on-going follow-up traveling control (step S6), the starting of follow-up traveling control processing is inhibited. This operation history flag FT is reset when a specified releasing condition for suspending the follow-up traveling control is established (step S2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular travel control device which performs speed control for following a preceding vehicle while maintaining a distance between the vehicle and the preceding vehicle.

[0002]

2. Description of the Related Art A conventional traveling control device for a vehicle is disclosed, for example, in Japanese Patent Application Laid-Open No. 3-153426.

This conventional example has an auto cruise control function for controlling the vehicle speed so as to maintain a preset vehicle speed, and when a slip occurs in the vehicle, the throttle valve is closed according to the slip amount and the engine is closed. In a vehicle engine output control method having a traction control function for reducing output, a traction control signal is output from a traction control system to an auto cruise control system, and the traction control signal is output during normal auto cruise control in the auto cruise control system. It is determined whether or not the traction control signal has been input. When the traction control signal is not input, the auto cruise control is continued, and when the traction control signal is input, the auto cruise control is prohibited and the traction control is prioritized. A method is disclosed.

[0004]

However, in the above-described conventional engine output control method, it is determined whether or not a traction control signal is input during the auto cruise control. The auto cruise control can be prohibited or continued depending on the presence or absence of the traction control signal.However, the auto cruise control starts when the vehicle is running on a low friction coefficient road such as a snowy road, a frozen road, or a rainy road. Cannot be prohibited, and there is an unsolved problem that the steering stability is reduced by starting the auto-cruise control or the follow-up running control developed from the auto-cruise control.

Accordingly, the present invention has been made in view of the above-mentioned unsolved problems of the prior art, and the following running control on a road surface having a low friction coefficient is prohibited to ensure the steering stability or to reduce the low friction coefficient. A vehicle capable of performing stable traveling according to a change in road surface condition by notifying the driver that the vehicle is traveling on the traveling road surface and then letting the driver determine whether or not to perform follow-up traveling control. The purpose of the present invention is to provide a travel control device for a vehicle.

[0006]

According to a first aspect of the present invention, there is provided a vehicle travel control apparatus for controlling a speed of following a preceding vehicle while maintaining a predetermined distance between the vehicle and the preceding vehicle. In a vehicle traveling control device having a following traveling control unit, a road surface state detecting unit for detecting a traveling road surface state, and prohibiting control of the following traveling control unit when the road surface state detecting unit detects a low friction coefficient road surface. Control inhibiting means.

According to the first aspect of the present invention, when the vehicle shifts from a running state on a road surface with a high friction coefficient to a running state on a road surface with a low friction coefficient, the road surface state detecting means immediately detects the road surface with a low friction coefficient. Following running control is prohibited, and steering stability is ensured.

A second aspect of the present invention is a vehicle cruise control device having follow-up cruise control means for performing speed control for following the preceding vehicle while keeping the inter-vehicle distance to the preceding vehicle at a predetermined value. A road surface condition traveling control unit that performs traveling control according to the road surface friction condition, and that the road surface condition traveling control unit is in the low friction coefficient road surface control state when the road surface condition traveling control unit enters a control state corresponding to the low friction coefficient road surface. It is characterized by comprising a control state storing means for storing, and a control prohibiting means for prohibiting the control of the following running control means when the low friction coefficient road surface control state is stored in the control state storing means.

In the invention according to the second aspect, by shifting from the running state of the road surface with the high friction coefficient to the running state of the road surface with the low friction coefficient, the road surface condition traveling control means can change the control state according to the low friction coefficient road surface. Then, the fact that the road surface is in the low friction coefficient road control state is stored in the control state storage means. Therefore, the follow-up traveling control is stopped immediately when the control state storage unit stores that the low friction coefficient road surface control state has been stored during the follow-up traveling control of the following traveling control unit,
When the following running control is not performed by the following running control means, and when the following running control is started, when the low friction coefficient road surface control state is stored in the control state storage means, the start of the following running control is stopped. In addition, the following running control at the time of running on a road surface with a low coefficient of friction is prohibited to ensure the steering stability.

According to a third aspect of the present invention, in the vehicle traveling control apparatus according to the second aspect of the present invention, the control state storage means determines that a low friction coefficient road surface control state is determined within a unit time by the road surface condition traveling control means. It is characterized in that it is configured to store the low friction coefficient road surface control state when it is repeated more times.

In the invention according to claim 3, when the number of times that the road surface condition traveling control means enters the low friction coefficient road surface control state is less than a predetermined number of times per unit time, the control state storage means, Since it is determined that the road surface is a transient low-friction coefficient road surface such as a manhole cover surface and the low-friction-coefficient road surface control state is not stored, unnecessary suspension of the following running control is prevented.

Further, according to a fourth aspect of the present invention, in the vehicle traveling control device according to the second or third aspect, the control prohibiting unit is configured to control the low-friction in the control state storage unit when the control of the following traveling control unit is started. Notifying means for notifying that the low friction coefficient road surface control state is stored when the coefficient road surface control state is stored, and checking operation detecting means for detecting a driver's checking operation after notifying the state by the notifying means, When the confirmation operation is detected by the confirmation operation detection means, the control of the following travel control means is permitted, and when the confirmation operation is not detected, the control of the following travel control means is prohibited. .

In the invention according to the fourth aspect, when the low friction coefficient road surface control state is stored in the control state storage means, the notification means notifies the driver of the low friction coefficient road surface control state, and The confirmation operation detection means detects whether or not the user has performed the confirmation operation. When the confirmation operation is performed, the follow-up traveling control of the follow-up traveling control means is continued, and when the confirmation operation is not performed, the follow-up traveling control is stopped. Therefore, it is possible to determine whether or not to perform the follow-up traveling control according to the driver's intention.

According to a fifth aspect of the present invention, there is provided a vehicle traveling control device according to any one of the second to fourth aspects, wherein the road surface condition traveling control means comprises traction control means for preventing wheel slip. It is characterized by having.

According to the fifth aspect of the present invention, the traction control state for suppressing the slip on the drive wheels is frequently performed on the low friction coefficient road surface, and the low friction coefficient road surface is reduced from the traction control state. It is possible to reliably recognize that the vehicle is running.

Further, a vehicle running control device according to a sixth aspect of the present invention is the vehicle running control device according to any one of the second to fourth aspects, wherein the road surface condition running control means is a side slip prevention control means for preventing a side slip of the vehicle body. It is characterized by being.

According to the sixth aspect of the present invention, when the vehicle is in a turning state, side slip of the vehicle body occurs on a road surface with a low coefficient of friction. It is possible to reliably recognize that the vehicle is traveling on a road surface with a low friction coefficient from the suppression control state.

According to a seventh aspect of the present invention, in the vehicle travel control device according to any one of the second to fourth aspects, the road surface condition traveling control means is constituted by an antilock brake control means. And

In the invention according to claim 7, the wheels tend to lock on a road surface with a low friction coefficient,
Antilock brake control for suppressing wheel lock is frequently performed, and it is possible to reliably recognize that the vehicle is traveling on a road surface with a low friction coefficient from this antilock brake control state.

Further, in the vehicle traveling control device according to claim 8, in the invention according to claim 5, the control state storage means is provided when the traction control means operates within a traveling acceleration range used in normal control. The low friction coefficient road surface control state is stored.

In the invention according to claim 8, when the running acceleration is within the running acceleration range used in normal control, it is determined that the vehicle is not in a sudden acceleration state but in a normal running state, and in this state, the traction control means is controlled. Is activated, it can be more reliably recognized that the vehicle is in the low friction coefficient road surface control state.

According to a ninth aspect of the present invention, in the vehicle traveling control device according to the sixth aspect of the present invention, the control state storage means is configured to operate when the sideslip prevention control means operates within a lateral acceleration range used in normal control. The low friction coefficient road surface control state is stored.

According to the ninth aspect of the present invention, when the lateral acceleration is within the range of the lateral acceleration used in the normal control, when the anti-skid control means is operated, it is more surely recognized that the road surface has a low friction coefficient. can do.

Further, according to a tenth aspect of the present invention, in the vehicle traveling control apparatus according to the seventh aspect, the control state storage means operates the antilock brake control means within a traveling deceleration range used in normal control. In this case, it is configured to memorize the low friction coefficient road surface control state when the vehicle is in the state.

Also in the invention according to the tenth aspect, it is possible to more reliably recognize that the anti-lock brake control is in the low friction coefficient road surface control state when the anti-lock brake control is operated within the travel deceleration range used in the normal control. it can.

[0026]

According to the first aspect of the present invention, when the vehicle shifts from a traveling state on a road surface with a high friction coefficient to a traveling state on a road surface with a low friction coefficient, the road surface state detecting means detects the low friction coefficient road surface. Since the start of the follow-up running control is immediately prohibited, there is an effect that the steering stability can be ensured.

According to the second aspect of the present invention, by shifting from the traveling state on the road surface with the high friction coefficient to the traveling state on the road surface with the low friction coefficient, the road surface condition traveling control means can change the control state according to the low friction coefficient road surface. Then, since the low friction coefficient road surface control state is stored in the control state storage means, it is determined that the low friction coefficient road surface control state is obtained in the control state storage means during the following travel control of the following travel control means. When the information is stored, the following cruise control is immediately stopped, and an effect is obtained that the steering stability can be ensured.

According to the third aspect of the present invention, when the number of times that the road surface condition traveling control means enters the low friction coefficient road surface control state is less than a predetermined number of times per unit time, the control state storage means includes: Since it is determined that the road surface is a transient low friction coefficient road surface such as a manhole cover surface and the low friction coefficient road surface control state is not stored, the following traveling control state is continued, and unnecessary An effect is obtained that interruption of the following running control can be prevented.

According to the fourth aspect of the invention, when the low friction coefficient road surface control state is stored in the control state storage means, the driver is informed of the low friction coefficient road surface control state by the notification means, and the operation is performed. The confirmation operation detection means detects whether or not the person has performed the confirmation operation, and when the confirmation operation is performed, the follow-up traveling control of the following traveling control means is continued, and when the confirmation operation is not performed, the following traveling control is stopped. It is possible to determine whether or not to perform the follow-up running control according to the driver's intention, and it is possible to obtain an effect that the following-out running control can be continued while the driver pays attention on a road surface having a low friction coefficient.

According to the fifth aspect of the present invention, the traction control state for suppressing the slip on the drive wheels is frequently performed on the road surface with a low friction coefficient, and the road surface with the low friction coefficient is reduced from the traction control state. The effect is obtained that the user can reliably recognize that the vehicle is running.

According to the sixth aspect of the invention, when the vehicle is in a turning state, side slip of the vehicle body occurs on a road surface with a low coefficient of friction. The effect of being able to reliably recognize that the vehicle is traveling on a low friction coefficient road surface from the suppression control state is obtained.

According to the seventh aspect of the present invention, the anti-lock brake control for suppressing the wheel lock is frequently performed on a road surface with a low friction coefficient due to the tendency of the wheels to lock. The effect of being able to reliably recognize that the vehicle is traveling on a low friction coefficient road surface is obtained.

According to the present invention, when the traveling acceleration is within the traveling acceleration range used in the normal control, it is determined that the vehicle is not in the sudden acceleration state but in the normal traveling state, and in this state, the traction control means is determined. Is activated, it is possible to more reliably recognize that the vehicle is in the low friction coefficient road surface control state.

According to the ninth aspect of the present invention, when the lateral acceleration is within the range of the lateral acceleration used in the normal control, when the anti-skid control means is operated, it is more reliably recognized that the road surface has a low friction coefficient. The effect is obtained.

According to the tenth aspect, when the anti-lock brake control is operated within the travel deceleration range used in the normal control, it is possible to more reliably recognize that the road surface is in the low friction coefficient road control state. The effect that it can be obtained is obtained.

[0036]

Embodiments of the present invention will be described below 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 1FR.
RR is a rear wheel as a driving wheel, and rear wheels 1RL, 1R
R is driven to rotate by the driving force of the engine 2 being transmitted via the automatic transmission 3, the propeller shaft 4, the final reduction gear 5, and the axle 6.

Front wheels 1FL, 1FR and rear wheels 1RL, 1R
R is provided with a disc brake 7 for generating a braking force, and the braking oil pressure of the disc brake 7 is controlled by a braking control device 8.

Here, 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 traveling control controller 20. Have been.

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 output by controlling the engine speed by adjusting the opening of the throttle valve and adjusting the opening of the idle control valve to control the engine speed by controlling the engine speed. Although a control method is conceivable, in the present embodiment, a method of adjusting the opening of the throttle valve is employed.

Further, the automatic transmission 3 is provided with a transmission control device 10 for controlling the shift position. When an up / down shift command value TS is input from a travel control controller 20 described later, the transmission control device 10 performs up shift or down shift control of the shift position of the automatic transmission 3 in response to the input. Is configured.

On the other hand, the vehicle is provided with wheel speed sensors 13FL, 13FR and 13RL, 13RR for detecting the wheel speeds of the front wheels 1FL, 1FR and the rear wheels 1RL, 1RR, and detects the yaw rate ψ generated in the vehicle. yaw rate sensor 14, lateral acceleration sensor 15 for detecting a lateral acceleration G _Y generated in the vehicle, the braking pressure for detecting a master cylinder pressure of the steering angle sensor 16 and the braking detects a steering angle θ of a steering wheel (not shown) to Sensor 17
Are arranged.

In addition, an inter-vehicle distance sensor 18 including a radar device as 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.

Then, the wheel speed sensors 13FL to 13R
The output signals of the R, yaw rate sensor 14, lateral acceleration sensor 15, steering angle sensor 16, and braking pressure sensor 17 are input to the running state controller 19, and the vehicle state controller 19 controls the wheel speed sensors 13FL.
Based on the wheel speeds Vw _{FL to} Vw _RR detected at 13 to 13RR, an estimated vehicle speed V _C is calculated, and each wheel speed Vw
_{FL ~Vw RR} a differentiated wheel acceleration speed Vw _{FL '~Vw RR'}
The anti-lock brake control process is executed based on these, and the driving force control process for preventing the slip of the driving wheels is executed when the anti-lock brake control process is not being executed. When the control process is not executed, the steer characteristic is matched by matching the side slip amount of the vehicle on a road surface with a low friction coefficient such as a snowy road or a frozen road to a target side slip amount based on the driver's steering operation amount and braking operation amount. A side slip control process for stabilizing is executed, and when the driving force control process or the side slip control process is executed, an execution state signal SS having a logical value “1” indicating this is output to the following cruise control controller 20 described later. .

Here, in the side slip control process, the target side slip amount is calculated based on the steering angle θ detected by the steering angle sensor 16 and the master cylinder pressure PB detected by the braking pressure sensor 17, and is detected by the yaw rate sensor 14. Yaw rate ψ and lateral acceleration G _Y detected by lateral acceleration sensor 15
Is calculated based on the actual slip amount, and each of the wheels 1FL is adjusted so that the calculated actual slip amount matches the target slip amount.
The braking pressure applied to the disc brake 7 of .about.1 RR is controlled to match the steering characteristic intended by the driver.

The inter-vehicle distance D detected by the inter-vehicle distance sensor 18, the vehicle speed V _C output from the traveling state control controller 19, and an execution state signal indicating that the braking force control processing or the side slip control processing is being executed. SS, the switch signal SI of the ignition switch, and the switch signals S _M and S _{SET of} the main switch SW _M and the set switch SW _S for selecting whether or not to perform the following traveling control are input to the following traveling controller 20. The inter-vehicle distance L detected by the inter-vehicle distance sensor 12 by the follow-up traveling control controller 20 and the vehicle state control controller 1
9 based on the vehicle speed V _C input from the brake control device 9, the engine output control device 9, and the transmission control device 1.
By controlling the vehicle state control controller 0 to perform the following traveling control while following the preceding vehicle while maintaining an appropriate inter-vehicle distance, the execution state signal SS of the logical value “1” is input from the vehicle state controller 19. Then, the vehicle state control operation history flag F is set to "1", this is ended when the following running control is being performed, and the start of the following running control is prohibited when the following running control is not being performed.

The main switch SW _M has a self-holding function, and is in a self-holding state when it is in the ON position, supplies power from the ignition switch to the set switch SW _S , and neutralizes from the ON position. The self-holding state is continued even after returning to the position, and the self-holding state is released when the self-holding state is set to the off position or when the ignition switch is turned off.

Next, the operation of the first embodiment will be described with reference to a follow-up traveling control procedure shown in FIG. 2 and a follow-up travel control procedure shown in FIG.

First, the following running management processing shown in FIG. 2 is executed as a main program. First, in step S1, it is determined whether or not the ignition switch switch signal SI has changed from the off state to the on state, or whether the main switch SW _M It is determined whether or not the switch signal _SM has changed from the on state to the off state.

If the result of this determination is that the switch signal SI has changed from the off state to the on state or the switch signal _SM has changed from the on state to the off state, the process proceeds to step S2, where the controller for the running state control is executed. In step 19, the operation history flag FT indicating whether the driving force control or the skidding state control has been executed is reset to "0" indicating that the driving force control or the skidding state control has not been executed, and the tracking control is being performed. The following running state flag FS indicating whether or not the following running state is reset to "0", and the following running state inhibition flag F indicating whether or not the following running control described later is prohibited.
After resetting F to "0" which permits the following running control, the process returns to step S1.

If the result of the determination in step S1 is that the switch signal SI has not changed from the off state to the on state or the switch signal _SM has changed from the on state to the off state, the process proceeds to step S3.

In step S3, it is determined whether or not the follow-up running control is being executed. This determination is made as to whether or not a following running state flag FS set in a following running control process of FIG. 3 described later is set to “1”, and the following running state flag FS is reset to “0”. If it is, it is determined that the following running control is not being executed, and the process proceeds to step S4.

In step S4, the control state signal SS from the traveling state control controller 19 is read, and it is determined whether or not this is a logical value "1". The skid state control is executed, and it is determined that the vehicle is traveling on a low friction coefficient road surface such as a snowy road, a frozen road, or a rainy road, and the process proceeds to step S5.

In step S5, an operation history flag F indicating that the driving force control or the skid state control has been executed.
After T is set to "1", the process proceeds to step S6.
On the other hand, when the result of the determination in step S4 is that the control state signal SS is a logical value "0", it is determined that the vehicle is not traveling on a road surface with a low friction coefficient but a road surface with a high friction coefficient such as a dry pavement road, and the step Move to S6.

In step S6, it is determined whether or not the following condition is satisfied. The start condition of the following running control is determined by the switch signal S _SET of the set switch SW _S.
And determines whether or not the switch signal S _SET is in the ON state, that is, whether the main switch SW _M and the set switch SW _S are both ON and the driver has requested to start the follow-up traveling control. It is determined whether or not V _C is equal to or higher than the set vehicle speed V _{S. When} the switch signal S _SET is in the off state, it is determined that there is no request to start the follow-up running control, and the timer interrupt processing is terminated as it is. After returning to the predetermined main program, the switch signal S _SET
Is in the ON state and when V _C ≧ V _S, it is determined that there is a request from the driver to start the following running control, and that the running speed exceeds the control starting vehicle speed and the following running control conditions are satisfied, and the process proceeds to step S7. Transition.

In step S7, the operation history flag F
It is determined whether or not T is set to "1". If it is reset to "0", it is determined that the vehicle is traveling on a road surface with a high friction coefficient and stable following traveling control is possible. The process proceeds to step S8, in which the following running control prohibition flag FF is set to "1" to permit the start of the following running control process, and then the process returns to step S1.

On the other hand, if the result of the determination in step S3 is that the follow-up traveling control inhibition flag FF has been reset to "0", it is determined that the follow-up traveling control is being performed, and the routine proceeds to step S9, where the traveling state is determined. Control controller 19
From the control state signal SS, and this is a logical value "1".
Is determined, and when the logical value is “1”, the process proceeds to step S10.

In step S10, an operation history flag FT indicating that the driving force control or the side slip state control has been executed is set to "1" in the same manner as in step S5 described above, and then the process proceeds to step S11, where the following running is performed. Prohibition flag F
F is set to "1" to inhibit the follow-up traveling control, and then the process returns to step S1.

If the result of the determination in step S9 is that the execution state signal SS from the traveling state control controller 19 is "0", the flow shifts to step S12, where the switch signal S _SET of the set switch SW _S is turned off. It is determined whether or not there is, and when it is in the off state, it is determined that the driver has requested to stop the following travel control, and the process proceeds to step S11. When it is in the on state, the following travel control is continued. And the process returns to step S1.

Further, the following running control process shown in FIG.
A predetermined time (for example, 10
msec) is executed as a timer interrupt process.
In step S20, it is determined whether or not the following cruise inhibition flag FF is set to "1". When this flag is set to "1", it is determined that the following cruise control is prohibited, and the process proceeds to step S21. Then, after the following running control state flag FS indicating the following running control state is reset to "0" indicating that the following running is not controlled, the process is terminated, and the following running inhibiting flag FF is set to "1". Sometimes, it is determined that the following traveling control process is permitted, and the process proceeds to step S22.

In this step S22, the inter-vehicle distance D from the actual preceding vehicle detected by the inter-vehicle distance sensor 12 is read, and then the process proceeds to step S23, where the estimated vehicle speed inputted from the traveling state control controller 19 is inputted. V
_After reading _C (n), the process proceeds to step S24.

In step S24, the estimated vehicle speed V
_{From C} (n) and the time T ₀ (inter-vehicle time) until the vehicle reaches the current position L ₀ [m] behind the preceding vehicle, the distance between the preceding vehicle and the vehicle is calculated according to the following equation (1). Calculate the target inter-vehicle distance D ^* .

D ^* (n) = V _C (n) × T ₀ + D ₀ (1) By adopting the concept of inter-vehicle time, the inter-vehicle distance is set to increase as the vehicle speed increases. You. Incidentally, D ₀ is stopped when the inter-vehicle distance.

Next, the process proceeds to step S25 to determine whether or not the inter-vehicle distance D (n) is less than or equal to the target inter-vehicle distance D ^* (n). If D (n)> D ^* (n), then Inter-vehicle distance D
(n) exceeds the target inter-vehicle distance D ^* (n), and it is determined that it is possible to reduce the inter-vehicle distance as an acceleration state, and the process shifts to step S26, based on the preset target vehicle speed V ^* . The target acceleration / deceleration G ^* is calculated according to the following equation (2).
This is updated and stored in the acceleration / deceleration storage area of the memory, and the process proceeds to step S28.

[0064] _{^{G * = K A × (V}} * -V (n)) + L A ............ (2) where, K _A and L _A are constants. On the other hand, step S
When the determination result of 25 is D (n) ≦ D ^* (n), it is determined that the inter-vehicle distance D (n) is shorter than the target inter-vehicle distance D ^* (n) and it is necessary to increase the inter-vehicle distance as a deceleration state. Then, the process proceeds to step S27, calculates the target acceleration / deceleration G ^* based on the following equation (3), updates and stores this in the acceleration / deceleration storage area of the memory, and then proceeds to step S28.

[0065] _{^{G * = K B × (D}} (n) -D * (n)) -L B ............ (3) where, K _B and L _B are constants. In step S28, 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 S29. .

Here, the throttle opening command value θ is equal to the target acceleration / deceleration G in the acceleration state where the target acceleration / deceleration G ^* is positive.
^* To calculate the throttle opening degree change amount Δθ to increases in the positive direction with an increase in the target deceleration is until to reach a predetermined value -G _S from "0" when the target deceleration G ^* is negative The throttle opening change amount Δθ that increases in the negative direction in accordance with the increase of G ^{* in} the negative direction is calculated, and the calculated throttle opening change amount Δθ is added to the current throttle opening command value θ to obtain a new throttle opening command value θ. such calculates the throttle opening command value theta, the target deceleration G ^* is set to "0" or a value in the vicinity of the throttle opening command value theta when exceeding the predetermined value -G _S.

The up / down shift command value TS
Is an up / down shift command value of the automatic transmission 3 based on the calculated throttle opening command value θ and the vehicle speed V (n) with reference to a shift control map similar to the shift control in a normal automatic transmission. Calculate TS.

In step S29, a target braking pressure P _B ^* is calculated based on the target acceleration / deceleration G ^* stored in the acceleration / deceleration storage area, and a braking pressure control process for outputting this to the braking control device 8 is performed. , The timer interrupt process is terminated, and the process returns to the predetermined main program.

[0069] Here, the target braking pressure P _B ^* is the target deceleration G ^* with reference to the braking pressure calculation map shown in FIG. 4 which has previously been stored in the memory on the basis of calculating the target braking pressure P _B ^* .
Map out the braking pressure calculation, as shown in FIG. 4, the target acceleration G ^* the horizontal axis and the vertical axis to the target braking pressure P _B ^*, a and negative when the target acceleration G ^* is positive Predetermined value -G
Maintaining the target braking pressure P _B ^* "0" is until exceeds _S, the target acceleration G ^* exceeds a predetermined value or more -G _S, proportional to the increase in the negative direction of the target acceleration G ^* Thus, the target braking pressure P _B ^* is set to increase linearly.

In the above processing, the processing of steps S4, S5, S9 and S10 in FIG. 2 corresponds to the control state storage means, and the processing of step S7, steps S9 to S11 and the processing of step S20 in FIG. And a control start prohibiting means for prohibiting the control start in step S7 and step S20 in FIG.
The processing of steps S21 to S28 in FIG. 3 corresponds to the following travel control means.

Therefore, if it is assumed that the vehicle is stopped with the ignition switch turned off and the main switch SW _M and the set switch SW _S both turned off, the controllers 19 and 2 are in this state.
0, the power is not turned on, the anti-lock brake control, the driving force control, and the skid state control are not executed by the traveling state controller 19, and the following traveling control is executed by the following traveling controller 20. It has not been.

In this stopped state, when the ignition switch is turned on and the engine is started, the power is turned on to each of the controllers 19 and 20, and the predetermined processing is started by these.

At this time, since the vehicle is in a stopped state, the running state control controller 19 does not execute the antilock brake control, the driving force control and the side slip state control.
In the following-traveling control controller 20, first, the following-traveling management process of FIG. 2 is executed, and the state of the ignition switch changes from the off state to the on state.
The process proceeds from step 1 to step S2 to reset the operation history flag FT indicating that the driving force control or the skid state control has been executed to "0" and to set the following travel control inhibition flag FF to "0". Then, the process returns to step S1.

In this state, the following travel prohibition flag FF is reset to "0", but the following traveling control is not started because the following traveling control process of FIG. 3 is not activated.

Then, when the process returns to step S1 in the following running management process of FIG. 2, since the ignition switch is in the ON state, the process proceeds to step S3, and the following running state flag FS is reset to "0". It is determined whether or not the following running state flag FS is set to “0” in step S2 described above.
Then, the execution state signal SS from the traveling state control controller 19 keeps the logical value "0" because the vehicle is in the stopped state and the driving force control and the side slip state control are not performed. Therefore, the process shifts to step S6 without shifting to step S5, so that the operation history flag FT continues to be reset to “0”.

Thereafter, the vehicle is started to run on a road surface having a high friction coefficient such as a dry paved road, and after or before the driver turns on the main switch SW _M and turns on the set switch SW _S. Then, the follow-up traveling management process of FIG.
_{When the S} switch signal S _SET is turned on and the estimated vehicle speed V _C becomes equal to or higher than the set vehicle speed V _S , it is determined that the start condition of the following driving control is satisfied, and the process proceeds to step S7.

Also in this step S7, since the vehicle is traveling on a road surface with a high friction coefficient and the driving force control and the side slip state control are not performed, the state of the operation history flag FT is reset to "0". Therefore, the process proceeds to step S8 to start the following travel control process of FIG. 3 to start the following travel control.

Therefore, when the follow-up traveling control process of FIG. 3 is started, the process shifts from step S20 to step S22, and the follow-up traveling control based on the following distance D and the estimated vehicle speed V _C of the own vehicle is performed. The process starts, and in step S31, the following running state flag FS indicates “1” indicating that the following running control is being performed.
Is set to

In this follow-up running control, the set vehicle speed is maintained when the preceding vehicle does not exist, and when the preceding vehicle exists, the target acceleration / deceleration G ^* is determined based on the inter-vehicle distance D and the target inter-vehicle distance D ^*. is calculated, the engine control process or the braking control processing is executed accordingly, follow-up running control is performed so as to maintain the estimated vehicle speed V _C target inter-vehicle distance corresponding to D ^*.

As described above, when the following running state flag FS is set to "1", the processing shifts from step S3 to step S9 in the processing of FIG. 2, and the driving force control or the side slip state control is not executed and , Switch signal S
_{When the SET} is in the off state, the process returns to the step S1 to continue the following running control.

However, during follow-up running control on a road surface with a high friction coefficient, the vehicle is running on a low friction coefficient road surface such as a snowy road or an icy road, and the driving wheels slip and the driving force control process is executed. When a side slip occurs during a turn and a side slip control process is executed, the traveling state controller 19 is controlled.
The execution state signal SS output from the CPU becomes the logical value "1". In the processing of FIG. 2, the process proceeds from step S9 to step S10, where the operation history flag FT is set to "1", and then to step S11. Then, the follow-up traveling control inhibition flag FF is set to "1".

For this reason, when the follow-up running control process of FIG. 3 is executed thereafter, steps S20 to S20 are executed.
Then, the flow goes to 21 to reset the following running state flag FS to “0” and then terminate the following running control process, thereby stopping the following running control.

On the other hand, in the processing of FIG. 2, the following running state flag FS is reset to "0", so that the processing shifts from step S3 to step S4, at which point the driving force control and the side slip state control are terminated. The running state signal S output from the running state control controller 19
Since S has returned to the logical value "0", the process directly proceeds from step S4 to step S6, and since the switch signal S _SET of the set switch SW _S is kept on, the process proceeds to step S7. The operation history flag FT is “1”
Is maintained, the follow-up traveling control prohibition flag FF is kept set to "1" without moving to step S8, and the following-up traveling control process is prohibited from being restarted.

Similarly, when starting on a road surface with a low coefficient of friction such as a snowy road or a frozen road, the driving force control or the skid state control is often performed at the time of starting. It is forbidden.

As described above, when the vehicle is running on a low friction coefficient road where the vehicle is slippery, the driving force control or the skid state control is executed by the running state controller 19, and the execution state signal SS becomes the logical value " By setting to 1 ", the following traveling control by the following traveling control controller 20 is prohibited. When the following traveling control is executed while traveling on a road surface with a low friction coefficient, the following distance D is set. Even if engine control or braking control is performed in accordance with the target acceleration / deceleration G ^* calculated based on the magnitude relationship with the target inter-vehicle distance D ^* , accurate follow-up traveling cannot be performed due to slippage at the wheels 1FL to 1RR. The state can be reliably avoided.

During the following running, the set switch SW
_SIs turned off and the switch signal S _SETTo the off state
The process from step S12 in the process of FIG.
Proceed to step S11 to prohibit following driving control
The flag FF is set to "1" and the following drive control is stopped.
Stopped and then returns to step S1 when step S1 is completed.
3 through step S4 to step S6.
Switch SW_SIs off, so
By returning to step S1, the following travel control prohibition state is maintained.
Carry.

When the vehicle travels on a road surface with a low friction coefficient, the running history flag FT is set to "1" and the following traveling control is prohibited. When it is desired to start the traveling control, the main switch SW _M is temporarily changed from the on state to the off state, so that the processing of FIG.
Then, the operation history flag FT is reset to "0".

Therefore, after that, the main switch SW_MTo
Set to ON state and set switch SW _STurn on
Thereby, in the processing of FIG.
The process proceeds to step S8 via S4, S6, and S7, and
The following cruise control process is started and the following cruise control is restarted.
Can be made.

Further, when the ignition switch is turned off after the vehicle is stopped and the ignition switch is turned on again, the operation history flag FT
Is reset to "0", so that the following running control on the road surface with a high friction coefficient is possible.

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, when the vehicle is traveling on a low friction coefficient road surface and a following traveling start request is made after the following traveling control is performed and the following traveling prohibition state is set, or when starting on a low friction coefficient road surface, When a follow-up traveling control start request is made, the fact that the traveling road surface is a low-friction coefficient road surface is notified, and when the driver performs a confirming operation corresponding thereto, the following traveling control is started. .

That is, in the second embodiment, as shown in FIG. 5, the follow-up traveling management process executed by the follow-up traveling control controller 20 is the same as the follow-up traveling management shown in FIG. In the processing, step S
Between step 7 and step S8, there is an operation history of driving force control or side slip state control, and step S41 for notifying the driver that the vehicle is traveling on a road surface with a low friction coefficient and whether or not the driver's confirmation operation has been performed Step S42 is provided to determine whether or not the operation proceeds to step S8 when there is a driver's confirmation operation, and returns to step S1 when there is no driver's confirmation operation. The same processes as those in FIG. 5 are performed, and the same processes as those in FIG. 5 are denoted by the same step numbers, and detailed description thereof is omitted.

Here, in the notification processing of the low friction coefficient road surface in step S32, assuming that an AV system equipped with a liquid crystal display having a touch panel is mounted, for example, "driving force control / side skid" With the history of state control operation: confirm the road surface condition. ", And then, in step S43, a confirmation button for setting and a confirmation button for cancellation are displayed on the screen corresponding to the touch panel, and a confirmation button for setting. When is selected, the process proceeds to step S8, and when the cancel confirmation button is selected, the process returns to step S1.

According to the second embodiment, the main switch SW _M for performing the following running control after the following running control is prohibited by running on the low friction coefficient road surface.
Is in the ON state, it is determined whether or not the driver has an intention to start the follow-up cruise control. To start the follow-up running control of FIG.

Therefore, the driver can judge the road surface condition and start the follow-up running control with his / her intention. For example, when the driver runs on a relatively short road surface that is partially frozen, the driver has a low coefficient of friction. When the vehicle has returned to a state in which the vehicle travels on a road surface with a high coefficient of friction after passing through the vehicle, the following travel control can be restarted immediately.

In the above-described second embodiment, the case where a message is displayed on the liquid crystal display screen when notifying the driver has been described. However, the present invention is not limited to this. In vehicles that have a message, it is possible to notify that there is a history of traveling on a road surface with a low coefficient of friction by voice guidance together with the display of a message, and it is also possible to omit the message display and provide only voice guidance .

In the second embodiment, the confirmation button is displayed on the liquid crystal display using the touch panel. However, the present invention is not limited to this. A confirmation switch may be provided on the front panel or the like in advance. Further, the user may be prompted to re-operate the main switch SW _{M. In} this case, as described above in the first embodiment, the processing shifts from step S1 to step S2 in FIG. Is reset to "0", the follow-up traveling control can be restarted.

Further, in the second embodiment,
Although the case where the notification to the driver is performed using the liquid crystal display has been described, any other display device such as a display using a cathode ray tube or a plasma display can be applied instead.

Next, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, when the driving force control or the number of sideslip state controls is less than a predetermined number of times, there is a possibility that the vehicle is traveling on a road with a low friction coefficient, so the driver is notified and the following traveling control is performed. Is determined to be continued, and if the number of times is equal to or greater than a predetermined number, it is determined that the vehicle is traveling on a road surface with a low friction coefficient, and the following traveling control is prohibited.

That is, in the third embodiment, as shown in FIG. 6, in the processing of FIG. 5 in the above-described second embodiment, the processing in step S2 determines the number of actuations N of the driving force control or the side slip state control. Step S45 of clearing to "0" and setting the following cruise control prohibition flag FF to "1", and the processing of steps S5 and S10 for incrementing the number N of times of driving force control or side slip state control. Steps S7 are omitted, instead of being replaced with S46 and S47, respectively. Instead, step S48 for determining whether or not the number of operations N is "0" and whether or not the number of operations N is "1" Step S49 is provided for determining whether or not N> 0 when the result of determination in step S48 is N = 0. Proceeds to step S49, the when the determination result of step S49 is N = 1 and goes to the step S41, except that it is set to directly returns to step S1 when it is N> 1 5
The same processes as those in FIG. 5 are executed, and the same processes as those in FIG. 5 are denoted by the same step numbers, and detailed description thereof is omitted.

According to the third embodiment, when the driving force control or the skid state control is executed by the running state control controller 19 when the following running control is started, the execution state signal SS from the controller 19 is issued. Is the logical value "1"
The number of times of operation N is incremented in step S46 every time.

Therefore, when the follow-up running control is started, the process moves from step S1 to step S45 in the initial state, and after the number of operations N is cleared to "0", the driving force control or the side slip state control is performed. If not, the number of operations N is maintained at "0", so that step S48 is performed.
Then, the process proceeds from step S8 to step S8 to start the following travel control process, thereby immediately starting the following travel control shown in FIG.

Then, after the following running control is started,
When the driving force control or the skid state control is performed while traveling on the road surface with the low friction coefficient, the process proceeds from step S9 to step S11 via step S47, and the following travel control inhibition flag FF is set to “1” to follow the road. After the travel control is stopped, when the follow-up travel control is started again, when the vehicle is traveling on a road surface with a low friction coefficient and the driving force control or the side slip control is executed, steps S4 to S46 are executed.
The operation number N is incremented to "1".
Becomes

For this reason, the process proceeds to step S49 via step S48, and since N = 1, the process proceeds to step S41. As in the second embodiment, the driver is notified of the operation history, and When the driver confirms the continuation, the process proceeds from step S42 to step S8 to start the following travel control process and start the following travel control of FIG.

However, after the resumption of the following running control,
The driving force control or the skidding state control is executed again, the following running control is stopped, and the driving force control or the skidding state control is executed again before or before the start request of the following running control is performed again, and the number of operations is performed. If N is incremented and is equal to or more than "2", steps S47, S47
Since the process returns to step S1 without going to step S8 via 48, the following travel control process is not started, and the state in which the start of the following travel control is prohibited is continued.

Therefore, according to the third embodiment, the driving force control or the side slip state control is executed at the start of the following running control, and the number of operations N is sequentially added. When the number of actuations is "0", the follow-up traveling control is started unconditionally. However, when the number of operations N is "1", the following traveling control is started after the driver's judgment is requested. Then, it is determined that the vehicle is traveling continuously on the low friction coefficient road surface, and the following traveling control is prohibited, so that the optimal following traveling control management according to the road surface condition can be performed.

In the third embodiment, the case where the number of actuations of the driving force control or the side slip state control is counted at the start of the following running control has been described. However, the present invention is not limited to this. Judgment of the road surface condition by the number of operations per hit, measurement of the execution time of the driving force control or the side slip control, and when the duration is shorter than a set time (for example, about 0.5 sec), follow the driver after confirmation of the driver. The control may be started, and when the time is equal to or longer than the set time, the following running control may be prohibited.

In the first to third embodiments, the case where both the driving force control and the side slip state control are performed by the traveling state controller 19 has been described.
The present invention is not limited to this, and either one of the two controls may be performed. In short, the control that is performed when the vehicle is running on a low friction coefficient road surface may be performed. .

Next, a fourth embodiment of the present invention will be described with reference to FIGS. In the fourth embodiment, when the driving force control is executed when the predetermined acceleration condition is satisfied, it is determined that the vehicle is traveling on a road surface with a low friction coefficient, and the execution and start of the following traveling control are prohibited. It is something to do.

In the fourth embodiment, as shown in FIG. 7, in the configuration of FIG. 1 in the first embodiment, a longitudinal acceleration sensor 21 for detecting a longitudinal acceleration newly generated in the vehicle is provided. provided, longitudinal acceleration X _G detected by the longitudinal acceleration sensor 21 are inputted to the follow-up run control controller 20, and the control state signal SS when only the driving force control is executed from the running state control controller 19 is is output to the follow-up run controller 20, a low acceleration G _a at the time of acceleration detected by the longitudinal acceleration sensor 21 when the driving force control is executed by the following travel management process in follow-up running control controller 20 is preset It is assumed that the vehicle is traveling on a low friction coefficient road surface when the acceleration is less than a set acceleration G _UP corresponding to the maximum acceleration when traveling on the friction coefficient road surface. 1 except that the setting is made so as to prohibit execution and start of the following cruise control upon judgment.
The same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

Here, as shown in FIG. 8, first, in step S51, it is determined whether or not the ignition switch switch signal SI has changed from the off state to the on state, or whether the main switch SW _M has been switched. It is determined whether or not the signal _SM has changed from the on state to the off state.

If the result of this determination is that the switch signal SI has changed from the off state to the on state or that the switch signal _SM has changed from the on state to the off state, the flow shifts to step S52 to inhibit the following travel control. The following-traveling prohibition flag FF is reset to “0” that permits the following-traveling control, and the following-traveling state flag FS indicating whether or not the following-traveling control is being performed is set when the following-traveling control is not being executed. After resetting to "0", the process returns to the step S51.

If the result of determination in step S51 is that the switch signal SI has not changed from the off state to the on state or the switch signal _SM has changed from the on state to the off state, the flow shifts to step S53.

In step S53, it is determined whether or not the following running control is being performed with the following running state flag FS set to "1", and the following running state flag FS is set to "0".
When it is reset to, it is determined that the follow-up traveling control is prohibited, and the process proceeds to step S54.

In step S54, the control state signal SS from the traveling state control controller 19 is read, and it is determined whether or not this is a logical value "1".
When it is determined that the driving force control is being executed, the process shifts to step S55.

In step S55, the acceleration G _A detected by the longitudinal acceleration sensor 21 is read, and this is set to a set acceleration G _UP (for example, 0.06 G It is determined whether it is less than (degree).

Here, when G _A ≧ G _UP , since an acceleration greater than the set acceleration G _UP has occurred, it is determined that the vehicle is traveling on a road surface with a high friction coefficient, and the process directly proceeds to step S57. When G _A <G _UP , a longitudinal acceleration smaller than the set acceleration G _UP has occurred, so that
It is determined that the vehicle is traveling on a low friction coefficient road surface, and the flow shifts to step S56 to execute the following traveling control prohibition flag FF
Is set to "1", and the routine goes to step S57.

In step S57, the set switch SW
It reads the switch signal S _SET of _S, the switch signal S
_It is determined whether or not there is a request from the driver to start the following cruise control when _SET is turned on, and it is determined that there is no request to start the following cruise control when the switch signal S _SET is in the off state. Returning directly to step S51, when the switch signal S _SET is turned on, it is determined that there is a request from the driver to start the follow-up running control, and when the estimated vehicle speed V _C becomes equal to or higher than the set vehicle speed V _S. The process moves to step S58.

In this step S58, it is determined whether or not the follow-up running inhibition flag FF is set to "1".
When it is reset to "0", it is determined that the vehicle is traveling on a road surface with a high coefficient of friction, and that stable follow-up traveling control is possible, and the process proceeds to step S59.
The following cruise control process is started to start the cruise control, and the process returns to step S51.

On the other hand, when the result of the determination in step S53 is that the following running state flag FS is set to "1", it is determined that following running control is being performed, and the routine proceeds to step S60, where the running state control is performed. The control state signal SS from the controller 19 is read, and it is determined whether or not this is a logical value "1". When the control state signal SS is a logical value "1", the process proceeds to step S61.

In this step S61, the follow-up running inhibition flag FF is set to "1" in the same manner as in step S56 described above, and then the flow returns to step S51. Also, the determination result of step S60 is determined by the running state control controller 19.
When the execution state signal SS is "0", the process proceeds to step S62 to determine whether or not the switch signal S _SET of the set switch SW _S is in the off state. It is determined that there has been a request to stop the traveling control, and the flow shifts to step S61. If it is in the ON state, it is determined that the following travel control is to be continued, and the flow returns to step S51.

According to the fourth embodiment, similarly to the first embodiment, when the ignition switch is turned on from the off state and the engine is started,
The process proceeds from step S51 to step S52, in which the follow-up traveling inhibition flag FF and the follow-up traveling state flag FS are both reset to “0” and initialized.

Thereafter, if the driving wheels slip when the vehicle is accelerated on a high-friction road surface in order to start the vehicle, the driving force control is executed by the traveling state control controller 19. longitudinal acceleration G _a detected by the longitudinal acceleration sensor 21 at this time is set acceleration G
_{Since it is UP} or more, in the process of FIG.
5 directly goes to step S57, and the follow-up traveling inhibition flag FF is not set to "1".

At this time, the main switch SW _M and the set switch SW _S are turned on, and the switch signal S _SET
Requesting follow-up driving control by turning on
When the estimated vehicle speed V _C becomes equal to or higher than the set vehicle speed V _S , the process proceeds to step S58.

At this time, since the follow-up traveling inhibition flag FF is still reset to "0", step S5
9 and the following cruise control process of FIG. 3 is started, the timer interrupt process is started, and the cruise control is performed so that the following distance D matches the target following distance D ^*. Be started.

However, when the driving wheels slip when the vehicle starts running on a road surface with a low friction coefficient and the driving force control is executed by the traveling state control controller 19, the process from step S54 to step S54 in the processing of FIG. S55 proceeds to, since the traveling road surface has a low friction coefficient, set the longitudinal acceleration G _a detected by the longitudinal acceleration sensor 21 acceleration G _UP
Since the smaller state is maintained, the process proceeds to step S56, and the following-travel-prohibition flag FF is set to "1".

For this reason, the estimated vehicle speed V _C becomes smaller than the set vehicle speed V.
_{When S} is reached and the process proceeds to step S58, the follow-up traveling control process of FIG. 3 is not started because the following-up traveling inhibition flag FF is set to "1", and the start of the following-up traveling control is inhibited. Is done.

When the vehicle starts running on a road surface with a high friction coefficient and the driving force control is executed, and the driving force control is executed, it is determined that the vehicle is traveling on a road surface having a low friction coefficient and the following driving is performed. When the prohibition flag FF is set to “1”, the following traveling control process of FIG. 3 is completed.

[0128] In this state, when a condition that has run a high friction coefficient road surface, by again turning on the main switch SW _M from an off state, the follow-up run inhibit flag FF is reset to "0" Therefore, the following running control can be started again.

As described above, also in the fourth embodiment, the slip occurs in the drive wheels and the running state control controller 19
When the drive force control is executed in, they are traveling on the low frictional coefficient road surface when the longitudinal acceleration G _A generated in the vehicle at that time is less than the set acceleration G _UP, is possible to perform precise follow-up run control When it is determined that the vehicle cannot be driven, the start of the following traveling control can be prohibited, and the traveling state on the road surface with a low friction coefficient can be more reliably detected.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In the fifth embodiment, when the antilock brake control is executed, when the deceleration at that time is less than the set deceleration, it is determined that the vehicle is traveling on a road surface with a low friction coefficient, and the following traveling control is performed. Is prohibited from being started.

In the fifth embodiment, the control state signal SS having the logical value "1" is output to the follow-up traveling control controller 20 when the traveling state control controller 19 executes the antilock brake control. 9 and the follow-up traveling control process by the follow-up traveling control controller 20 is performed as shown in FIG. 9 in the above-described process of FIG. 8 in which the processes of steps S54 and S60 perform the anti-lock brake control. The process is changed to steps S65 and S66 for determining whether or not the deceleration G _DA detected by the longitudinal acceleration sensor 21 is the set deceleration G corresponding to the preset maximum deceleration on the road surface with a low friction coefficient. FIG except that it is modified _DOWN (for example, about 0.2 G) whether it is less than the determining step S67 It was treated in the same manner as, given the same step numbers to the corresponding processing in the FIG. 8, and detailed description thereof will be omitted this.

Also in the fifth embodiment, the antilock brake control is executed before the start of the follow-up running control, and the deceleration G _{DA at} that time is set so as to correspond to the maximum deceleration on the low friction coefficient road surface. When it is equal to or more than the deceleration G _DOWN , it can be determined that the vehicle is traveling on a high friction coefficient road surface, and when it is less than the set deceleration G _DOWN , it can be determined that it is traveling on a low friction coefficient road surface. On the other hand, when the vehicle is traveling on a road surface with a low friction coefficient, the start of the follow-up traveling control is reliably prohibited.

In the fourth and fifth embodiments, the case where the longitudinal acceleration sensor 21 is used to detect the acceleration and the deceleration has been described. However, the present invention is not limited to this. The acceleration or the deceleration may be calculated by differentiating V _C or calculating the amount of change per unit time.

Next, a sixth embodiment of the present invention will be described with reference to FIG. In the sixth embodiment, when the lateral acceleration generated in the vehicle when the side slip state control is executed is less than the set acceleration corresponding to the maximum lateral acceleration on the low friction coefficient road surface, the low friction coefficient road surface is It is determined that the vehicle is traveling and the start of the following traveling control is prohibited.

[0135] That is, the sixth embodiment, although not shown, the lateral acceleration G _Y detected by the lateral acceleration sensor 15 is also input to the following cruise control controller 20, in FIG. 10 in this follow-up running control controller 20 A follow-up running management process is executed.

This follow-up traveling management processing is the same as that of the processing of FIG. 8 in the fourth embodiment except for steps S54 and S6.
Process 0 is changed to determining S71 and S72 whether skid state control is being executed, a low friction coefficient lateral acceleration G _Y is preset to the processing in step S55 is detected by the lateral acceleration sensor 15 Set lateral acceleration G _LAT corresponding to the maximum lateral acceleration on the road surface (for example, 0.2 G
The same processing as in FIG. 8 is performed except that step S73 is performed to determine whether
Steps corresponding to those in FIG. 8 are denoted by the same step numbers, and detailed description thereof is omitted.

Also in the sixth embodiment, the side slip state control is executed before the start of the follow-up running control, and the lateral acceleration G _{Y at} that time is set to the set lateral acceleration corresponding to the maximum lateral acceleration on the low friction coefficient road surface. When the acceleration is equal to or higher than _GLAT , it can be determined that the vehicle is traveling on a high friction coefficient road surface, and when the acceleration is less than the set deceleration _GLAT , it can be determined that the vehicle is traveling on a low friction coefficient road surface, When the vehicle is traveling on a road surface with a low friction coefficient, the start of the following traveling control is reliably prohibited.

In the sixth embodiment, the case where the lateral acceleration generated in the vehicle is detected by using the lateral acceleration sensor 15 is described. However, the present invention is not limited to this, and the estimated vehicle speed V _C is not limited to this. And the turning radius R calculated based on the steering angle θ may be calculated according to the following equation (1), or may be calculated based on the yaw rate 検 出 detected by the yaw rate sensor 14.

G _Y = V _C ² / R (1) In the fourth to sixth embodiments, the start of the following running control is prohibited when the low friction coefficient road surface is detected. However, the present invention is not limited to this.
Alternatively, the follow-up running control may be started after the notification to the driver as in the third embodiment, or the control mode may be changed according to the number of times the low friction coefficient road surface is detected.

Further, in each of the above embodiments, the target inter-vehicle distance D ^* is calculated, and the target inter-vehicle distance D ^* is compared with the actual inter-vehicle distance D to obtain the target acceleration / deceleration G ^*.
Has been described, but the present invention is not limited to this. The time (inter-vehicle time) T until the host vehicle reaches the rear of the preceding vehicle L ₀ (m) based on the inter-vehicle distance D (n) is described. _A target vehicle speed V ^* (n) is determined so that ₀ becomes constant, and an engine output command value α is calculated based on a deviation ΔV (n) between the target vehicle speed V ^* (n) and the actual vehicle speed V (n). In some cases, the engine is controlled based on the calculated engine output command value α to bring it into an accelerated state, and when negative, the target braking pressure is set by PD control or PID control based on the speed deviation ΔV (n). Good.

Further, in each of the above embodiments,
The case where the estimated vehicle speed V _C is calculated based on the wheel speeds Vw _{FL to} Vw _RR of the four wheels has been described. However, the present invention is not limited to this. The vehicle speed may be calculated by detecting the rotation speed on the output side of the automatic transmission 3, or may be calculated by integrating the longitudinal acceleration.

Further, in each of the above embodiments,
A case has been described where it is determined that the vehicle is traveling on a road surface with a low friction coefficient when the driving force control or the side slip state control is executed by the traveling state control controller 19, but the invention is not limited thereto. The road surface condition may be detected based on a difference in rotational speed or a difference in rotational speed between front wheels and rear wheels used for control.

Further, in each of the above-described embodiments, the case where the two controllers of the traveling state control controller 19 and the follow-up traveling control controller 20 are provided is described. However, the present invention is not limited to this. The side slip state control and the following traveling control may be executed by one controller.

Further, in each of the above-described embodiments, the case has been described in which whether or not to execute the follow-up traveling control process is managed by the follow-up traveling control process. However, the present invention is not limited to this. Alternatively, it may be executed as one process.

Further, in each of the above embodiments,
Although the following description has been given of the case where the following cruise control process is started by the following cruise management process, the present invention is not limited to this. The always following cruise control process is executed as a timer interrupt process, and the process of FIG. After the processing of step S20 is performed, the timer interruption processing may be terminated and the processing may return to the processing of FIG. 2. In this case, when the following-traveling inhibition flag FF is set to "1", the processing proceeds from step S20. After step S21, the timer interrupt process is terminated as it is, and the following running control process of steps S22 to S31 is performed only when the following running inhibition flag FF is "0".

In each of the above embodiments,
Although the case where the main switch SW _M and the set switch SW _S are applied has been described, the present invention is not limited to this, and one of the switches may be omitted.

In each of the above embodiments, the description has been given of the case where the following running control is started when the own vehicle speed becomes equal to or higher than the set vehicle speed V _S. However, the present invention is not limited to this. Only the turning on of one of the switch SW _M and the set switch SW _S may be set as the start condition of the follow-up traveling control. In this case,
When the vehicle starts, when the switch is turned on from the off state, and when the control is prohibited during the following cruise control, the vehicle is driven for a predetermined distance or until the predetermined time elapses. It is preferable to provide a monitoring period for monitoring the execution state of the side slip state control and / or to start the following travel control after the monitoring period elapses in order to prevent the following travel control from being carelessly started.

Further, in each of the above embodiments, 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. .

In each of the above embodiments,
Although the case where the present invention is applied to a rear wheel drive vehicle has been described, the present invention can also be applied to a front wheel drive vehicle and a four wheel drive vehicle, and furthermore, an electric vehicle using an electric motor instead of the engine 2, The present invention is also applicable to a hybrid vehicle using both the engine 2 and the electric motor.
In this case, an electric motor control device may be applied instead of the engine output control device.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating an example of a follow-up traveling management processing procedure of a follow-up traveling control controller.

FIG. 3 is a flowchart illustrating an example of a cruise control process performed by a cruise control controller;

FIG. 4 is an explanatory diagram showing an example of a target braking pressure calculation map showing a relationship between a target acceleration / deceleration and a target braking pressure.

FIG. 5 is a flowchart illustrating an example of a follow-up traveling management processing procedure according to the second embodiment of the present invention.

FIG. 6 is a flowchart illustrating an example of a follow-up traveling management processing procedure according to a third embodiment of the present invention.

FIG. 7 is an overall configuration diagram of a fourth embodiment of the present invention.

FIG. 8 is a flowchart illustrating an example of a follow-up traveling management processing procedure according to a fourth embodiment.

FIG. 9 is a flowchart illustrating an example of a follow-up traveling management processing procedure according to a fifth embodiment of the present invention.

FIG. 10 is a flowchart illustrating an example of a follow-up traveling management processing procedure according to a sixth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION 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 Distance between vehicles 13FL to 13RR Wheel speed sensor 14 Yaw rate sensor 15 Lateral acceleration sensor Reference Signs List 16 steering angle sensor 17 braking pressure sensor 19 traveling state controller 20 follow-up traveling controller 21 longitudinal acceleration sensor

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60T 8/24 B60T 8/24 F02D 29/02 301 F02D 29/02 301D 311 311A F-term (Reference) 3D041 AA31 AA41 AA48 AA49 AB01 AC01 AC16 AC18 AC28 AD44 AD47 AD50 AD51 AE00 AE03 AE31 AE41 AE45 3D044 AA25 AA45 AB01 AC05 AC24 AC55 AC56 AC59 AD00 AD02 AD17 AD21 AE19 3D045 BB40 EE21 GG10 GG25 BB18 BB25 BB26 BB26 BB26 BB23 BB26 BB26 BB26 BB26 BB26 BB26 BB26 BB23H18 AA05 BA01 BA04 BA14 CA05 CA09 CB04 DB02 DB03 DB05 DB16 DB17 DB18 EA01 EB01 EB03 EB04 EC04 FA04 FA10

Claims (10)

[Claims] 1. A traveling control device for a vehicle having a following traveling control means for performing speed control for following a preceding vehicle while maintaining a predetermined inter-vehicle distance with a preceding vehicle, comprising: a road surface state detecting means for detecting a traveling road surface state; And a control prohibiting means for prohibiting the control of the following running control means when the low friction coefficient road surface is detected by the road surface state detecting means. 2. A vehicle running control device having a following running control means for performing speed control for following a preceding vehicle while maintaining a predetermined inter-vehicle distance with a preceding vehicle. Situation traveling control means, control state storage means for storing the low friction coefficient road surface control state when the road surface situation traveling control means enters a control state corresponding to a low friction coefficient road surface, and the control state storage And a control prohibiting means for prohibiting the control of the following running control means when the low friction coefficient road surface control state is stored in the means. 3. The control state storage means stores the low friction coefficient road surface control state when the low friction coefficient road surface control state is repeated a predetermined number of times or more within a unit time by the road surface condition traveling control means. The vehicle travel control device according to claim 2, wherein the vehicle travel control device is configured as follows. 4. The control prohibiting means notifies that the low friction coefficient road surface control state is in effect when the low friction coefficient road surface control state is stored in the control state storage means at the start of control of the follow-up traveling control means. And a confirmation operation detecting means for detecting a driver's confirmation operation after the state is reported by the reporting means. When the confirmation operation detection means detects a confirmation operation, the control of the following traveling control means is permitted. The vehicle travel control device according to claim 2 or 3, wherein the control of the following travel control means is prohibited when no confirmation operation is detected. 5. The vehicle travel control device according to claim 2, wherein said road surface condition travel control means comprises traction control means for preventing wheel slip. 6. The vehicle travel control according to claim 2, wherein said road surface condition travel control means comprises side skid prevention control means for preventing sideslip of the vehicle body. apparatus. 7. The vehicular travel control device according to claim 2, wherein said road surface condition travel control means comprises an anti-lock brake control means. 8. The control state storage means is configured to store a low friction coefficient road surface control state when the traction control means operates within a travel acceleration range used in normal control. 6. The method according to claim 5, wherein
The traveling control device for a vehicle according to the above. 9. The control state storage means is configured to store a low friction coefficient road surface control state when the sideslip prevention control means operates within a lateral acceleration range used in normal control. The travel control device for a vehicle according to claim 6, wherein: 10. The control state storage means is configured to store a low friction coefficient road surface control state when the antilock brake control means is operated within a travel deceleration range used in normal control. The vehicle travel control device according to claim 7, wherein