JP2001047888A - Running controller for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge whether running control is continued or not by detecting a running situation when running control becomes a traction control condition at the time of running control of a vehicle. SOLUTION: When such running control that makes a set vehicle speed and an inter-vehicle distance set by a driver coincide with a target vehicle speed and a target inter-vehicle distance to make own vehicle speed VS coincide with the target speed is done, it is judged whether driver's steering become a countersteer condition or a predetermined running situation in which a condition in which a driven wheel is not rotated for a predetermined time is continued at the time of start or not, running control is continued when driver's steering does not become the predetermined running situation, but running control is stopped when it becomes the predetermined running situation to stabilize the behavior of own vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle traveling while maintaining a vehicle speed at a target vehicle speed set by a driver or a target vehicle speed calculated on the basis of a deviation between an inter-vehicle distance from a preceding vehicle and a target inter-vehicle distance. The present invention relates to a travel control device.

[0002]

2. Description of the Related Art As a conventional traveling control device for a vehicle, for example, JP-A-3-153426 (hereinafter, referred to as a first conventional example) and JP-A-6-191324 (hereinafter, referred to as a second conventional example). ) Are known. The first conventional example is provided with an auto cruise control function for controlling the vehicle speed so as to maintain a preset vehicle speed, and when a vehicle slips, the throttle valve is closed according to the slip amount and the engine output is reduced. Traction control function to reduce
There is disclosed an engine output control method in which auto cruise control is prohibited during traction control.

In the second conventional example, a traction control for detecting a slip amount of a vehicle and suppressing an accelerator signal in a direction to reduce the slip amount, a target vehicle speed are selected, and the target vehicle speed is maintained. Auto cruise control that adjusts the rack position of the fuel injection device is performed.If traction control is established during the auto cruise control, the auto cruise control is released, and auto cruise control is performed at least from the engine speed and the actual rack position. There is disclosed an engine output control device for a vehicle that performs traction control on an auto cruise accelerator signal to be executed and, at the same time, terminates the traction control and returns the auto cruise control.

[0004]

However, in the first and second conventional examples, when the traction control is executed, the automatic cruise control is prohibited or canceled, and the automatic cruise control is performed simultaneously with the termination of the traction control. Since the cruise control is restored, there is no problem if the vehicle speed is high and the vehicle quickly crosses a low friction coefficient road surface such as a snowy road, a frozen road, or a rainy road. When the vehicle is started from a state in which the vehicle is started and the drive wheels idle and cannot start, the traction control suppresses the rotation of the drive wheels and simultaneously inhibits or cancels the auto cruise control. Suspended,
As a result, the traction control is also stopped, so that the auto cruise control is restarted again, the drive wheels idle, and the traction control is started accordingly, and the auto cruise control is prohibited or canceled. Is repeated, and there is an unsolved problem of continuing a state in which the vehicle cannot start.

In a situation where traction control is started, the road surface has a low friction coefficient, so that when the lateral force of the drive wheels is reduced by disturbance, the behavior is disturbed, and it is necessary to steer the steering wheel. When the driving force becomes zero, the traction control is stopped and the automatic cruise control is stopped when the driving force becomes zero. When the cruise control is started, there is an unsolved problem that the lateral force of the drive wheel is reduced and the operation returns to a state where the operation of the steering wheel is continued.

Accordingly, the present invention has been made in view of the above-mentioned unsolved problems of the prior art, and the driving force suppression means (traction control means) is activated during traveling control, and the vehicle behavior is reduced. It is an object of the present invention to provide a vehicular travel control device capable of avoiding disturbance of vehicle behavior and a state in which the vehicle cannot be started by suspending the travel control when the vehicle is disturbed or a traveling state in which the vehicle cannot be started.

[0007]

According to a first aspect of the present invention, there is provided a vehicle travel control device for controlling at least a driving force so as to maintain a vehicle speed at a target vehicle speed. A vehicle driving control device including driving force suppressing means for suppressing driving force when a wheel slip state is greater than a predetermined slip state; a driving state detecting means for detecting a predetermined driving state of the vehicle; A control suspending unit for suspending the control of the traveling control unit when the driving condition suppressing unit is activated during the control of the traveling control unit, and the traveling condition detecting unit detects a predetermined traveling condition; It is characterized by having.

In the invention according to the first aspect, at least driving force control is performed by the traveling control means for maintaining the vehicle speed at the target vehicle speed calculated by the driver to maintain the target vehicle speed or the inter-vehicle distance at the target inter-vehicle distance. While doing,
Even when the driving force suppressing means is in the operating state, the driving state detecting means does not detect the rotation stop state of the non-driving wheels, or does not detect the predetermined driving state such as the steering state of the steering wheel. When the vehicle travels in a driving force suppression state in which the driving force control by the traveling control unit is suppressed by the driving force suppression unit, and when the traveling state detection unit detects that the vehicle is in a predetermined traveling state, the control suspension unit executes the traveling control. The control of the means is stopped to avoid a predetermined driving situation.

According to a second aspect of the present invention, in the vehicle traveling control apparatus according to the first aspect, the traveling state detecting means includes a steering state detecting means for detecting a steering state of the driver. When the steering state detected by the state detection means is equal to or greater than the predetermined steering state, the vehicle is configured to detect that a predetermined traveling state has been achieved.

In the invention according to the second aspect, when the driver detects a predetermined steering state with respect to a decrease in the lateral force of the wheel, for example, the behavior of the vehicle is disturbed by the steering state detection means. It detects that the vehicle is running. further,
According to a third aspect of the present invention, in the vehicle traveling control apparatus according to the second aspect, the steering state detecting unit detects a steering angle, a steering change number detecting unit detects a steering change number, and a steering change number detecting unit. It is characterized in that it is constituted by one of a steering angular velocity detecting means for detecting an angular velocity and a steering angular acceleration detecting means for detecting a steering angular acceleration.

In the invention according to claim 3, the steering angle detecting means, the steering angle change frequency detecting means, the steering angular velocity detecting means and the steering angular acceleration detecting means determine the predetermined steering state, that is, the lateral force of the driver's wheel. Accurately detect the steering state for a drop. Still further, according to a fourth aspect of the present invention, in the vehicle traveling control apparatus according to any one of the first to third aspects, the traveling condition detecting unit detects a wheel speed of a non-driving wheel. When the driving force suppression means is in the operating state, when the non-driving wheel speed detected by the non-driving wheel speed detecting means has continued the stop state for a predetermined time or more, a predetermined traveling state and It is characterized in that it is configured to detect that it has become.

In the invention according to the fourth aspect, when the vehicle is started by the traveling control means at the time of starting of the vehicle, a slip is generated in the drive wheels and the driving force suppression means is activated, and the vehicle is not driven. When the drive wheel speed detecting means detects that the non-drive wheels continue to be stopped,
When it is determined that the vehicle is in the start impossible state, the driving force control by the traveling control unit is stopped, and the vehicle can be started by a creep phenomenon, for example.

Further, according to a fifth aspect of the present invention, in the vehicle travel control device according to any one of the first to fourth aspects, the control suspension means represents control suspension when the control of the travel control means is suspended. It is characterized by being configured to give a warning. In the invention according to claim 5,
When stopping the control of the traveling control means by the control stopping means,
By warning the stop of the control, the driver can be surely recognized that the control of the travel control means has been stopped, and the operation is shifted to the driver's own starting operation.

[0014]

According to the first aspect of the present invention, the driving force suppressing means operates while the driving control is being performed by the driving control means to maintain the set vehicle speed or the target inter-vehicle distance. When it is in the state, the driving situation detection means,
For example, when a rotation stop state of the non-drive wheels is detected or a predetermined traveling state such as a steering state of the steering wheel is not detected, the driving force control by the traveling control unit is suppressed by the driving force suppression unit. Drive in the driving force restrained state,
When the traveling state detecting means detects that the vehicle is in a predetermined traveling state, the control suspending means stops the control of the traveling control means, thereby avoiding the predetermined traveling state and stabilizing the behavior. Can be

According to the second aspect of the invention, the steering state detecting means detects, for example, a predetermined steering state in which the driver is in a steering state due to a decrease in the lateral force of the wheel. At this time, it is detected that the vehicle is in a predetermined traveling state in which the behavior of the vehicle is disturbed. When the vehicle enters this state, the control by the traveling control unit is stopped, so that the driving force becomes zero, The effect of recovering the grip force and stabilizing the behavior can be obtained.

According to a third aspect of the present invention, the steering angle detecting means and the steering state detecting means comprise a steering angle change frequency detecting means, a steering angular velocity detecting means and a steering angular acceleration detecting means. Therefore, an effect is obtained that the predetermined steering state, that is, the driver can accurately detect the steering state of the steering wheel due to the decrease in the lateral force of the wheel.

Further, according to the vehicle traveling control apparatus of the present invention, when the vehicle is started by the traveling control means, a slip occurs in the driving wheels and the driving force suppressing means is activated. When the non-driving wheel speed detecting means detects that the non-driving wheels continue to be in a stopped state, it is determined that the vehicle is not in a startable state, so that the driving force control by the traveling control means is stopped. Thus, an effect is obtained that the driver can perform a reliable start, for example, due to a creep phenomenon.

Further, according to the vehicle travel control device of the fifth aspect, when the control suspension means suspends the control of the travel control means, the driver is warned of the suspension of the control, so that the driver can perform the travel control. It is possible to obtain an effect that it is possible to reliably recognize the suspension of the control of the means and to shift to the driver's own starting operation.

[0019]

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 provided with a preceding vehicle following control device that travels following a preceding vehicle. Are front wheels as driven wheels, 1RL, 1
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.

The front wheels 1FL, 1FR and the rear wheels 1RL, 1R
R is provided with a disk brake 7 as a brake actuator for generating a braking force.
The braking oil pressure of these disc brakes 7 is applied to a braking control device 8.
Is controlled by Here, the brake control unit 8 is adapted to generate a braking oil pressure in response to depression of a brake pedal, not shown, so as to generate a braking hydraulic pressure in accordance with a braking pressure command value P _BC from following controller 20 described below It is configured.

The engine 2 is provided with an engine output control device 11 for controlling the output. In the engine output control device 11, a throttle actuator 12 to adjust the throttle opening provided in the engine 2 according to the throttle opening command value TH _R from following controller 20 for depression amount and later of an accelerator pedal (not shown) And a traction control device 13 that controls at least the throttle opening so as to suppress wheel slip during rapid acceleration or running on a road surface with a low friction coefficient.

The traction control device 13 is provided for each wheel.
Wheel speed sensors 10FL-1 provided in 1FL-1RR
Wheel speed V based on wheel speed pulse output from 0RR
_WFL~ V_WRRIs calculated, and the front wheel side wheel speed as a driven wheel is calculated.
V_WFLAnd V_WFROf the vehicle speed V_SCalculate
And this vehicle speed V_SAnd the wheel speed V of the rear wheel as a drive wheel
_WRLAnd V_WRRDrive wheel slip ratio is calculated based on
And adjust the slot so that it matches the target slip rate.
Control the wheel opening to prevent wheel slip during acceleration.
Logical value when traction control is in progress
Control that becomes “1” and logical value “0” during non-control
The state signal TR is sent to the following control controller 20 described later.
Output and the calculated vehicle speed V_SAnd front wheels
Speed V_WFL,V_WFRIs output to the tracking control controller 20.
You.

On the other hand, a radar system which scans a laser beam as inter-vehicle distance detecting means for detecting an inter-vehicle distance to a preceding vehicle and receives reflected light from the preceding vehicle is provided below the vehicle body in front of the vehicle. An inter-vehicle distance sensor 14 having a configuration is provided. Further, the vehicle is provided with a steering angle sensor 15 for detecting the steering angle θ of the steering wheel.

The control state signal TR output from the traction control device 13, the own vehicle speed V _S and the front wheel speeds V _{WFL and} V _WF , the inter-vehicle distance L output from the inter-vehicle distance sensor 14, and the steering angle The steering angle θ output from the sensor 15 is input to the following control controller 20, and the following control controller 20 controls the following distance to the target following distance when the preceding vehicle is being captured. and outputs a vehicle speed V braking pressure command value _S the driver to control the set vehicle speed V _sET set P _BR and the target throttle opening degree TH _R when not captured in brake controller 8 and engine output controller 11 At the same time, when the following control is stopped, a control stop display is displayed on a display 21 such as a liquid crystal arranged at a position visible from the driver's seat.

This tracking control controller 20 is
Equipped with a microcomputer and its peripherals.
Depending on the software configuration of the computer, the control block shown in FIG.
Make up a lock. This control block is
After the laser beam is scanned by the sensor 14, the reflected light of the preceding vehicle
Is measured until the vehicle receives the light, and the following distance L
Ranging signal processing unit 21 for calculating
Distance L and traction control device 13 calculated by
Vehicle speed V read from_STarget distance L based on the target vehicle
Distance L ^*Target vehicle speed V to maintain^*To calculate the distance between vehicles
An inter-vehicle distance control unit 40 as control means, and the inter-vehicle distance
Target vehicle speed V calculated by control unit 40^*Target drive based on
Shaft torque T^*And a vehicle speed control unit 50 for calculating the vehicle speed
Target drive shaft torque T calculated by control unit 50^*Based on
Rottle actuator 12 and brake actuator
Target throttle opening TH with respect to_RAnd target braking pressure
P_BRAnd calculate them with the throttle actuator 13
And drive wheel axle torque output to brake actuator 7
Control unit 60.

An inter-vehicle distance control unit 40 calculates a target inter-vehicle distance L ^* between the preceding vehicle and the own vehicle based on the own vehicle speed V _S input from the traction control device 13, and the target inter-vehicle distance setting section 42 target inter-vehicle distance calculated by the L ^*, a vehicle distance L inputted from the distance measurement signal processing section 21, host vehicle speed V _S and the inter-vehicle distance based on L
And a vehicle distance control calculating section 43 for calculating a target vehicle speed V ^* to match the target inter-vehicle distance L ^* a.

When the following distance is in the following control state, the target vehicle speed V input from the following distance control unit 40 when the preceding vehicle is being captured by the following distance sensor 14.
_A smaller value between _L ^* and the set vehicle speed V _SET set by the driver is set as the target vehicle speed V ^* , and when the preceding vehicle is not captured, the set vehicle speed V _SET set by the driver is set as the target vehicle speed V ^*. The target vehicle speed setting unit 51 to be set and the target vehicle speed V ^* set by the target vehicle speed setting unit 51
A target drive shaft torque calculating section 52 for calculating a target drive shaft torque T _W ^* for matching _S.

As shown in FIG. 3, the drive shaft torque control unit 60 calculates a throttle opening command value θ _R and a brake fluid pressure command value P _BR for realizing the target drive torque T _W ^*. . Now, let the torque amplification rate of the torque converter be R
T, the R _AT gear ratio of the automatic transmission 3, a differential gear ratio R _DEF, the engine inertia J _E, when the engine rotational speed and N _E, the drive shaft torque T _W and the engine torque T _E and brake torque T _BR The relationship with (1)
It can be represented by an equation.

[0029] _{T W = K GEAR {T E} -J E (dN E / dt)} - T BR ............ (1) _{where, K GEAR = R T · R} AT · R DEF Accordingly, the target drive shaft torque T _W computes a target engine torque T _E ^* by the following equation (2) with respect to ^*, the target engine torque T _E ^*
The throttle opening command value theta _R to generate a calculated by referring to the engine map shown in FIG.

[0030] ^{_{T E * = J E (dN}} E / dt) + T W * / K GEAR ............ (2) where, if the throttle opening command value theta _R is "0" or more, using the brake Without using the engine torque alone, the target drive shaft torque T _W ^* can be achieved. On the other hand, if the throttle opening command value θ _R is less than “0”, the throttle opening is set to “0”, and the driving shaft torque is set to the target driving shaft torque in consideration of the driving shaft torque output by the engine 2 at this time. Calculate the brake operation amount to match T _W ^* .

From the above, the distribution control law of the target engine torque T _E ^* and the target brake torque T _BR ^* is as follows. (A) When the throttle opening command value θ _R > 0, T _BR ^* = 0 Therefore, the above equation (1) becomes the following equation (3).

T_W= K_GEAR｛T_E−J_E(DN_E/ Dt)｝ (3) Therefore, the target drive shaft torque T_W ^*For
The target engine torque T of the equation (4)_E ^*If you generate
Will be. T_E ^*= J_E(DN_E/ Dt) + T_W ^*/ K_GEAR (4) where the target brake torque T_BRIs "0",
Brake fluid pressure command value P _BRBecomes “0”. (B) Throttle opening command value θ_RWhen ≦ 0 Engine speed N_EEngine torque shown in Fig. 5 based on
Referring to the map, throttle opening θ_RIs “0”
Engine torque T_E0Is calculated. With this,
The expression (1) becomes the following expression (5).

[0033] _{T W = K GEAR {T E0} -J E (dN E / dt)} - T BR ............ (5) Accordingly, the target brake torque T _BR ^* is below relative to the target drive shaft torque T _W ^* ( 6) It is expressed by the equation. ^{_{T BR * = -T W * +}} K GEAR {T E0 -J E (dN E / dt)} ...... (6) , where the brake cylinder area A _B, the rotor effective radius R _B, the pad friction coefficient μ _{Assuming B} , a brake fluid pressure command value P _BR, which is a brake operation amount, with respect to the target brake torque T _BR ^* can be expressed by the following equation (7).

P_BR= (1 / K_BT) ・ T_BR ^* ............ (7) However, K_BT= 8 · A_B・ R_B・ Μ_B For this reason, the drive shaft torque control unit 60 uses the block shown in FIG.
As shown in the diagram, the target drive shaft torque T_W ^*Is divided by 6
1 and the coefficient K_GEARDivided by the target engine
Luc T_E ^*Is calculated, and this is calculated by the throttle opening calculation unit 62.
The throttle opening calculating section 62 supplies the target engine
Jin Torque T_E ^*And engine speed N _EFigure 4 based on
The throttle opening TH with reference to the engine map
This is supplied to the limiter 63 and the throttle
The maximum throttle opening from zero controllable by the
Throttle opening command value TH_RAs
Output to the engine output control device 11 and drive the target
Shaft torque T_W ^*Is supplied to the subtractor 64 to obtain the target drive
Shaft torque T_W ^*Is calculated according to the second term on the right side of the equation (6).
The value K calculated by the engine brake correction calculator 65
_GEAR｛T_E0−J_E(DN_E/ Dt) Subtract from 目標 and target
Brake torque T_BR ^*Is calculated and supplied to the divider 66.
To calculate the brake fluid pressure command
Value P_BIs calculated by the limiter 67 and the brake
Range from zero to maximum brake pressure controllable by tutor 7
To the brake fluid pressure command value P_BRAs braking control device
8 is output.

On the other hand, in the tracking control controller 20,
The control management process shown in FIG. 6 is executed. In this control management process, first, in step S1, a set switch (not shown) is turned on to match the own vehicle speed V _S with the set vehicle speed V _SET set by the driver, or set the inter-vehicle distance L to the target inter-vehicle distance L ^* . It is determined whether or not a tracking control state flag FS indicating whether or not the tracking control state to be matched is set to "1" indicating the tracking control state.
When S is reset to "0", the process waits until the following control state is set, and when the following control state flag FS is set to "1", the process shifts to step S2 and is input from the traction control device 13. It is determined whether or not the control state signal TS has a logical value “1”. If the control state signal TS has a logical value “0”, it is determined that the traction control is not being performed, and the process proceeds to step S
3, the following control process is performed by the inter-vehicle distance control unit 40, the vehicle speed control unit 50, and the drive shaft torque control unit 60, and then, the process returns to the step S1, and the control state signal TS
Is a logical value "1", it is determined that the traction control has been started, and the routine goes to Step S4.

In step S4, the steering angle sensor 15
Steering angle reads theta, the steering angle theta is equal to or a preset set steering angle theta _S above, when a theta ≧ theta _S, the process proceeds to step S5, visibility from the driver's seat After a control stop display indicating that the follow-up control has been stopped is displayed on a display 21 such as a liquid crystal disposed at a possible position, the process proceeds to step S
Then, the flow goes to 6 to reset the following control state flag FS to "0" to stop the following control in step S3, and then return to step S1.

The result of the determination in step S4 is that θ <θ
_{If S} , the process proceeds to step S7 to determine whether the front wheel speeds V _WFL and V _WFR as driven wheels are “0”, and if they are “0”, step S8.
Proceeds to the when the front wheel speed V _{WF L} and V _WFR is "0" is a state that has not been determined whether older than the predetermined time t _S, the predetermined time t _S has passed the step S1
The process returns to step S5 when the predetermined time t _S has elapsed.

Next, the operation of the above embodiment will be described.
Now, for example, a set switch (not shown) is turned on.
Therefore, the following control state flag FS is set to "1".
In a state where the driver has set, for example,
Constant vehicle speed V_SETLower vehicle speed V_SIt is following and running,
It is assumed that the traction control device 13 is inactive.
You. In this state, in the process of FIG.
From step S2 to step S3
As a result, the following control process corresponding to FIG.
Speed V_STarget inter-vehicle distance L based on ^*Is calculated, and
And the target vehicle speed V_L ^*Is calculated, and the target vehicle speed V_L ^*But
Target vehicle speed V^*And the target vehicle speed V^*And own vehicle speed V
_SSpeed gain K_SPDriving force calculated by multiplying
F_WRFrom the running resistance estimated value F_DHIs subtracted from the target driving force F _W
^*And calculate the tire radius R_HBy multiplying
And the target drive shaft torque T_W ^*And calculate the target drive axis
Torque T_WThrottle opening command value TH based on_Ras well as
Brake fluid pressure command value P_BRAnd output them to the engine.
By outputting to the force control device 11 and the braking control device 8,
And the inter-vehicle distance L becomes the target inter-vehicle distance L^*To match
The driving force or the braking force is controlled.

In this follow-up running state, the vehicle is running on a straight road on a low friction coefficient road surface such as a snowy road, a frozen road, a rainy road, etc., and as shown in FIG. When the rear wheels 1RL and 1RR enter a state in which wheel slip occurs and the wheel slip rate exceeds the target slip rate at the time t2, the traction control device 13 is activated and the wheel slip rate falls below the target slip rate. limiting the throttle opening command value TH _R in.

As described above, when the traction control device 13 is activated, as shown in FIG. 7 (a), the control state signal TS becomes a logical value "1". From step S3 to step S3. When the vehicle is traveling on a straight road and the vehicle does not skid, the steering angle θ detected by the steering angle sensor 15 is substantially “0”. When the front wheels 1FL and 1FR as driven wheels are rotating, and the wheel speed V
_Since both _WFL and V _WFR are values larger than “0”,
The process proceeds to step S3, and the tracking control is continued.

In a running state in which traction control is being performed on a road surface with a low coefficient of friction, when, for example, the vehicle comes into a corner at a time t3 and the vehicle slips, the driver steers the steering wheel in the skid direction. After starting, the vehicle enters the counter steer state, and at time t4, the steering angle θ
If There the set steering angle theta _S above as shown in FIG. 7 (c), in the processing of FIG. 6, step S from step S4
5, the control 21 displays a control stop display to stop the follow-up control on the display 21 to warn the driver of the stop of the follow-up control, and then proceeds to step S 6, as shown in FIG. Then, the following control is stopped, and the state shifts to an acceleration / deceleration operation state according to the driver's intention.

At this time, since the driver is in the follow-up control state and has not depressed the accelerator pedal, the driving force immediately becomes "0" and the grip force of the rear wheels 1RL and 1RR as the driving wheels is recovered. Thus, the side slip state of the vehicle is eliminated, the behavior of the own vehicle can be stabilized, and the counter steer state can be eliminated. Incidentally, in the conventional example, as shown in FIG. 8, when the traction control is started by the wheel slip rate generated at the drive wheel at the time t11 exceeding the target slip rate, the throttle opening is suppressed, Although the wheel speed of the drive wheel is limited,
By continuing the state in which the driving force is transmitted to the driving wheels, the wheel slip state continues, and the lateral force of the driving wheels remains reduced. Therefore, when approaching the corner at time t12, the driving wheels The skid occurs, and the driver steers the steering wheel to set a counter steer state in order to deal with the slip.However, since the driving force is transmitted, the counter steer state needs to be maintained. The tracking control must be released at the will of the person,
The running stability decreases.

Thereafter, the vehicle stops on a road surface with a low coefficient of friction while the preceding vehicle is capturing the preceding vehicle by a signal or the like. In this state, the set switch is turned on, and the running state flag FS is set to "1". In the process of FIG. 6, the process shifts from step S2 to step S3, when the vehicle returns to the following control state, when the preceding vehicle is stopped, the own vehicle also maintains the stopped state, and the preceding vehicle starts. Distance L
Increases to exceed the target inter-vehicle distance L ^* ,
Target vehicle speed V _L corresponding to this ^* is calculated, the target drive shaft torque T _W ^* corresponding to the same are computed by the throttle opening command value TH _R increases in the opening direction in response to this, the engine 2 A driving force is generated and transmitted to the driving wheels 1RL and 1RR via the automatic transmission 3, the propeller shaft 4, the final reduction gear 5, and the driving shaft 6.
These drive wheels 1RL and 1RR are driven to rotate from time t21 as shown in FIG. 9B.

At this time, since the road surface has a low coefficient of friction, a wheel slip occurs on the drive wheels 1RL and 1RR, and at time t2
2, the traction control device 13 is activated and the throttle opening TH is limited, so that when the host vehicle starts moving, the front wheels 1FL and 1FR as driven wheels are set as shown by broken lines in FIG. 9B. By the rotation, the wheel speeds V _WFL and V _WFR become larger than “0”. For this reason, in the process of FIG. 6, the process proceeds from step S4 to step S3 via step S7 to continue the following control process, so that the vehicle starts running following the preceding vehicle.

However, when the vehicle does not start and the front wheels 1FL and 1FR as driven wheels maintain the rotation stopped state due to a large wheel slip on the drive wheels 1RL and 1RR at the time of starting, In the process of FIG. 6, the process proceeds from step S7 to step S8, and the process proceeds to step S3 to continue the follow-up control process until a predetermined elapsed time t _S elapses.

Thereafter, the front wheels 1FL and 1FL as driven wheels
When the FR continues the rotation stop state and the predetermined elapsed time t _S has elapsed at time t23, it is determined that the vehicle cannot start and the process proceeds to step S23.
Then, the process proceeds from step S5 to step S5, and a display of control stop indicating that the follow-up control is stopped is displayed on the display 21, and then step S6 is performed.
Then, the follow-up control is stopped as shown in FIG. 9 (d), whereby the throttle opening TH is returned to "0", that is, the fully closed state, and the automatic transmission is automatically driven by a small driving force due to the creep phenomenon of the automatic transmission. The vehicle can be started.

By the way, in the conventional example, when the self-vehicle is started by the auto cruise from the stop state of the vehicle on the road surface with a low friction coefficient, when a large wheel slip occurs on the drive wheel and the vehicle cannot be started, As shown in FIG. 10 (a), the traction control is activated at time t31 to release the automatic cruise control. However, a cruise accelerator signal simulated by the accelerator signal for obtaining the vehicle speed during the automatic cruise travel is calculated. Since the traction control is performed on the cruise accelerator signal, the throttle opening is limited to a small value, so that the wheel slip of the drive wheel is settled and the traction control is performed at time t32.
Then, the process returns to the auto cruise control again and the occurrence of wheel slips is repeated, and the start-up impossible state of the own vehicle is continued until the driver cancels the auto cruise control.

In the above embodiment, the case where the counter steer state of the driver is detected when the steering angle θ is equal to or larger than the set steering angle θ _S has been described. However, the present invention is not limited to this. The number of changes in the angle θ, the steering angular velocity, and the steering angular acceleration may be detected, and the counter steer state may be detected based on these. Further, in the above-described embodiment, the case has been described where the control stop display is performed on the display 21 when the follow-up control is stopped.
The invention is not limited to this, and an alarm sound may be generated by applying an alarm sound generator. In other words, any alarm sound generator may be used as long as it can warn the driver that the follow-up control will be stopped.

Further, in the above-described embodiment, the case where the present invention is applied to the follow-up control device has been described. However, the present invention is not limited to this, and the present invention is applicable to any vehicle speed control that matches the own vehicle speed with the target vehicle speed. Can be applied. Furthermore, in the above embodiment, the front wheels 1FL and average value of the wheel speed V _WFL and V _WFR of 1FR as a driven wheel has been described a case where the host vehicle speed V _S, is not limited thereto, In a vehicle equipped with an anti-lock brake control device, the vehicle speed calculated by a vehicle speed estimating unit built in the anti-lock brake control device may be set as the own vehicle speed V _S.

Further, in the above embodiment, the brake actuator 7 constituted by a disc brake is used.
Although the case where the braking force is generated by controlling the braking pressure is described, the invention is not limited to this.
When an electric motor is applied as an actuator of a braking device, the present invention can be applied to a case where an electric output corresponding to the electric motor is controlled and a regenerative braking force is generated by an electric motor like an electric vehicle.

In the above embodiment, the case where the present invention is applied to a rear wheel drive vehicle has been described. However, the present invention can be applied to a front wheel drive vehicle, and the engine 2 is applied as a rotary drive source. Although the case has been described, the present invention is not limited to this, and an electric motor can be applied. Further, the present invention can be applied to a hybrid vehicle using an engine and an electric motor.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a specific configuration of a tracking control controller of FIG. 1;

FIG. 3 is a block diagram showing a specific example of a drive shaft torque control unit in FIG. 2;

FIG. 4 is a characteristic diagram showing an example of an engine map for obtaining an engine torque from a throttle opening.

FIG. 5 is a characteristic diagram for obtaining engine torque from the engine speed when the throttle opening is zero.

FIG. 6 is a flowchart illustrating an example of a control management process of the follow-up control controller in FIG. 1;

FIG. 7 is a time chart for explaining the operation of the embodiment of FIG. 1 when a side slip occurs.

FIG. 8 is a time chart for explaining the operation of the conventional example when a side slip occurs.

FIG. 9 is a time chart for explaining an operation at the time of start of the embodiment in FIG. 1;

FIG. 10 is a time chart for explaining an operation at the time of starting in a conventional example.

[Explanation of symbols]

 Reference Signs List 2 engine 3 automatic transmission 7 brake actuator 8 braking control device 10FL to 10RR wheel speed sensor 11 engine output control device 12 throttle actuator 13 traction control device 14 inter-vehicle distance sensor 15 steering angle sensor 20 tracking control controller 21 indicator 40 inter-vehicle distance Control unit 50 Vehicle speed control unit 56 Running resistance estimation unit

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference)

Claims (5)

[Claims] 1. A travel control means for controlling at least a driving force so as to maintain a vehicle speed at a target vehicle speed, and a driving force suppressing means for suppressing and controlling the driving force when a slip state of a driving wheel is larger than a predetermined slip state. A driving condition detecting means for detecting a predetermined driving condition of the vehicle; and a driving condition control device for controlling the driving condition when the driving force suppressing means is activated during the control of the driving control device. A travel control device for a vehicle, comprising: a control suspension means for suspending control of the travel control means when a predetermined travel situation is detected by the detection means. 2. The vehicle driving apparatus according to claim 1, wherein the traveling state detecting means includes a steering state detecting means for detecting a steering state of the driver, and a predetermined state when the steering state detected by the steering state detecting means is equal to or greater than a predetermined steering state. The travel control device for a vehicle according to claim 1, wherein the travel control device is configured to detect that a travel situation has occurred. 3. The steering state detecting means includes a steering angle detecting means for detecting a steering angle, a steering angle change frequency detecting means for detecting a steering angle change frequency, a steering angular velocity detecting means for detecting a steering angular velocity, and a steering angular acceleration. 3. The control device according to claim 2, wherein the steering angle acceleration detecting means detects the steering angular acceleration.
The traveling control device for a vehicle according to the above. 4. The non-driven wheel speed detecting means for detecting a wheel speed of a non-driven wheel, wherein the driving condition detecting means detects a wheel speed of the non-driven wheel. 4. The system according to claim 1, wherein a predetermined traveling state is detected when the non-driving wheel speed detected by the wheel speed detecting means continues to be stopped for a predetermined time or more. The travel control device for a vehicle according to any one of the above. 5. The control unit according to claim 1, wherein the control suspension unit issues a warning indicating the suspension of the control when the control of the traveling control unit is suspended. Travel control device for vehicles.