JPH0238173A - Slip controller of vehicle - Google Patents

Abstract

PURPOSE:To enhance the slip convergence characteristics of a driving wheel by controlling a brake in such a manner that when the slip of the driving wheel is restrained by the effect of braking, the specified control torque is temporarily applied to the driving wheel at the early starting time of slip control. CONSTITUTION:There is provided a driving torque adjusting means 22 which adjusts the driving torque acting on a driving wheel 6. This adjusting means 22 is controlled by a controller 23 according to the control torque which is so computed that the slip value of the driving wheel 6 to the surface of the road may become the specified target value determined on the bases of a plurality of input signals. In such slip controller there is provided an initial braking force control means 24 which controls the braking force of the driving torque adjusting means 22 to temporarily apply the specified control torque to the driving wheel 6 regardless of the slip value of the driving wheel 6 at the early starting time of the slip control for the driving wheel 6. So an excessive driving torque may be prevented from being applied to the driving wheel 6 and the slip thereof be effectively restrained and prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a slip control device for an automobile, which prevents slippage of the driving wheels of the vehicle and improves running stability.

(Prior Art) As a slip control device for this type of automobile, the present applicant previously disclosed in Japanese Unexamined Patent Publication No. 63-31866, which detects the slip value of the driving wheel of the vehicle with respect to the driven wheel. At the same time, by adjusting the drive torque acting on the drive wheels to bring the slip value of the drive wheels to the target slip value, the action of excessive drive torque is prevented, and the slip of the drive wheels is effectively suppressed. We are proposing something to prevent this. In the above proposal, the drive torque is adjusted using both the engine output and the brake force acting on the drive wheels, and this brake force is finely adjusted by feedback control.

(Problem to be Solved by the Invention) By the way, in the slip control of the drive wheels as described above, when the drive torque of the drive wheels is adjusted by the brake force, there is a control delay in the feedback control of the brake force. The feedback control amount becomes sufficiently large only when the wheel slip reaches its maximum, and from then on, the drive wheel slip is effectively suppressed.
It is desirable to effectively suppress slips from the beginning of their occurrence.

The present invention has been made in view of the above, and its purpose is to control the braking force so that a sufficiently large braking torque is applied to the drive wheels even when the slip of the drive wheels initially occurs. The purpose is to effectively suppress this from the beginning and accelerate the convergence of slip in the driving wheels.

(Means for Solving the Problems) In order to achieve the above object, the present invention does not perform feedback control of the brake force at the beginning of slippage of the driving wheels, and instead drives a predetermined value of braking torque regardless of the degree of slippage. In addition to the wheels, the responsiveness of the control has been improved.

That is, as shown in FIG. 1, the specific configuration of the present invention includes a drive torque adjustment means 22 that adjusts the drive torque acting on the drive wheels 6, and a slip value of the drive wheels 6 relative to the road surface that is adjusted to a plurality of values. The present invention is based on a slip control system for an automobile, which includes a control means 23 for controlling the drive torque adjustment means 22 so as to reach a predetermined target value determined based on an input signal.

An initial braking force is provided to control the braking force of the drive torque adjustment means 22 so that a predetermined value of braking torque is temporarily applied to the drive wheel regardless of the slip value of the drive wheel at the beginning of the drive wheel slip control. This is a configuration in which a control means 24 is provided.

(Function) With the above configuration, in the present invention, the drive torque adjusting means 2
2 is controlled by the control means 23, and the drive torque acting on the drive wheels 6 is adjusted by the engine output or braking force, or both, so that the slip value of the drive wheels 6 relative to the road surface reaches a predetermined target value. As a result of this control, excessive drive torque does not act on the drive wheels, and slip of the drive wheels 6 is effectively suppressed and prevented.

If slip occurs in the drive wheels due to the vehicle entering a road surface with a low coefficient of friction, the initial braking force control means 24 applies a sufficiently large braking force to the drive wheels 6 from the beginning of the drive wheel slip control. When the brake force is applied, a predetermined value of braking torque is temporarily applied quickly, so compared to the conventional feedback control that adjusts the brake force, the drive torque of the drive wheels can be controlled to decrease quickly. The slip of the drive wheels can be effectively suppressed from the beginning even when it is small, and the slip of the driving wheels can be quickly converged.

(Effects of the Invention) As explained above, according to the slip control device for an automobile of the present invention, when the slip of the drive wheels is suppressed by the action of the brake force, a predetermined value is temporarily set at the initial stage of the start of the slip control. Since the braking force is controlled so that braking torque is applied to the drive wheels, the drive torque of the drive wheels can be quickly reduced from the beginning of slip occurrence when the degree of slip is small.
The convergence of the slip can be accelerated, and the convergence can be improved.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 2 onwards.

FIG. 2 shows the overall schematic configuration of the slip control device for an automobile according to the present invention, in which 1 is an engine, 2 is, for example, 4 forward speeds,
It is an automatic transmission with one reverse gear, and the engine power shifted by the automatic transmission 2 is transmitted to the left and right rear wheels via a propulsion shaft 3, a differential device 4, and a rear axle 5 arranged behind the transmission 2. 6,6
The rear wheel 6 is used as the driving wheel, and the left and right front wheels 7, 7
is configured as a driven wheel.

Further, a throttle valve 10 is arranged in the intake passage 1a of the engine 1 to control the amount of intake air and adjust the engine output. The throttle valve 10 has no mechanical interlocking relationship with the accelerator pedal 11, and its opening degree is electrically controlled by a throttle actuator 12 composed of a step motor or the like.

Furthermore, wheel speed sensors 13, 13, etc. are provided near the front, rear, left, and right wheels 6, 7 to detect the rotational speed of the wheels, and opening sensors to detect the opening degree of the accelerator pedal 11. 14. Steering angle sensor 15 that detects the steering angle; Acceleration sensor 1 that detects vehicle acceleration
6 is provided.

Therefore, the detection signals of each of the above sensors 13 to 16 are CP
The controller 20 controls the opening of the throttle valve 10 with the throttle actuator 12 to adjust the engine output, and controls the rear wheels (drive wheels) 6.6. This is to suppress and prevent slippage.

Furthermore, the controller 20 is connected to a brake actuator 21 that adjusts the brake hydraulic pressure acting on the left and right drive wheels (rear wheels) 6, 6, and when the rear wheels 6, 6 wheel spin (slip), the engine In addition to controlling the output, the brake hydraulic pressure is also controlled to suppress slippage.

Therefore, the throttle actuator 12 and the brake actuator 21 adjust the throttle valve opening (that is, the engine output) and the braking force acting on the driving wheels 6, thereby adjusting the driving torque acting on the driving wheels 6. It constitutes a drive torque adjustment means 22.

Next, slip control by the controller 20 will be explained based on FIGS. 3 to 13.

First, to explain from the main flow of FIG. 3, after initialization in step SMI, in step SM2, detection signals from the above-mentioned sensors are input in step SM3 only when it is the measurement timing of various data, and in step SM4. The wheel spin of the drive wheel is determined based on the spin determination flow shown in FIG. 4, and the state of this spin is determined in step SM5 based on the state determination flow shown in FIG.

After that, in step sM6, the traction flag TRCP
It is determined whether traction control (slip control) is in progress based on the value of TRCF-(l), and if slip control of TRCF-(l is not in progress, the target throttle valve opening ATAG corresponding to the opening of the accelerator pedal 11 is determined in step SM7. , step SM
8, the value ATAG is set as the output value THR to the throttle actuator.

On the other hand, when slip control is in progress, the state of the wheel spin is determined in steps SM9 and SM+o based on the value of the state flag JP (immediately after the spin occurs in JP-1, immediately after the spin converges in JP-2), and the state of the wheel spin is determined immediately after the spin occurs. In the case of (JP-1), the friction coefficient of the road surface (hereinafter referred to as road surface μ) is determined in step SMI+ based on the road surface μ estimation flow shown in FIG. Step 5Ml only when spinning (initial flag MP-0)
3 to immediately greatly reduce the throttle valve opening.
The target throttle valve opening TAGETn for slip control is set to a predetermined small opening value SH. On the other hand, if the spin is not the first time (first time flag MP-1), the target slip rate is calculated in steps 5M14 and 5M15 based on the target slip rate determination flow in FIG. 7 in order to feedback control the throttle valve opening. At the same time, a target throttle valve opening TAGETn corresponding to this target slip rate is calculated based on the target throttle opening calculation flow shown in FIG.

On the other hand, immediately after the spin convergence of JP-2, step SM
16, in order to instantly return the throttle valve opening to a large degree, the current target throttle valve opening TAGETn is set by combining the previous value TAGETn-1 and a predetermined cover-opening value FTAC (
This is the sum of the value calculated in step 5C2 (described later) in FIG.

After that, in step 5M17, the first
Brake control ff1 based on the brake control flow shown in Figure 0.
In addition to calculating TB, in step 5Ml8, the target throttle valve opening TAGETn is corrected based on the target throttle valve opening correction flow shown in FIG. 12 in order to reduce or maintain the throttle valve opening during this brake control, Next, in step S M 19, it is determined whether or not to end the slip control based on the traction control end determination flow shown in FIG.

In order to actually control the brake hydraulic pressure acting on the throttle valve 10 and the drive wheels 6, when the timing for outputting the control signal has come in step 5M2G, step SM2 is performed.
+ outputs throttle valve opening control ff1T1 (R to the throttle actuator 12, and also outputs step SMη
In step 5M23, the brake control amount TB is output to the brake actuator 21, and the initial flag MP is set to MP-1.
After returning to step SM2, the process is repeated.

Next, the spin determination flow shown in FIG. 4 will be explained.

First, in step SAI, the front wheel speed WPR of the right wheel and left wheel is
, find the average speed WFN of NFL, and find the average speed WRN of the rear wheel speeds WRR and WRL of the right and left wheels,
In steps SA2 to SA4, are the speeds WRR and Wl of the right rear wheel and the left rear wheel relative to the average front wheel speed WPN? The slip rate S of L is determined by the spin judgment value S1(
For example, when comparing S+-1, 125), if both are less than S1, it is a good time when no spin occurs, so
Set the spin flag to 5F-0 in step SA5, and if only the right rear wheel is spinning, go to step S6 to set it to 5F-1; if only the left rear wheel is spinning, go to step SA7 to set 5P.
-2, if both rear wheels spin, 5 in step SA8.
In each case of spin flags 5F-1, 2, and 3, the traction flag TRCP-1 (when a spin occurs) is set in steps sA9 to SAI+, and the process returns.

Next, the state determination flow shown in FIG. 5 will be explained.

In steps SKI to S83, the values of the previous and current spin flags SFo and SF are determined, and SPo -0 and -) are determined.
If SF≠0 (immediately after spin occurs), step SS4
Set the status flag JP-1 to SFO≠0 and 5P-
If it is 0 (immediately after spin convergence), the state flag JP-2 is set in step S85.

Then, in step SSS, the current spin flag value SF
After setting the previous value SPo, it is determined whether the vehicle is stuck or not in step S87. If the vehicle is not stuck, the stuck flag is set to 5TF-0 in step S88, and if stuck, it is set to 5TF-1 in step S89. . Also, in step 5ale, it is determined whether or not the brake is acting on only one side of the left and right wheels (in the case of a split road), and if the road is not a split road, the split flag 5PF-0 is set in step SSO; Step 8B
Set +2 to 5PF-1 and return.

In the road surface μ estimation flow shown in FIG. 6, in step sc1, the maximum value G11aX of the longitudinal acceleration G of the vehicle immediately after the slip occurs
is determined based on the output of the acceleration sensor 16, and then, based on this maximum acceleration (+SaX), three zones ZNI (OG≦GIIax<
0.05G), ZN2 (0.05G ≦CIIax<
0.15G), ZN3 (0,150≦Gmax<0
．． 250 (G is the acceleration of gravity)), and the corresponding zones are divided into the following: Coverage in the corresponding zone - opening PTAC (opening increase immediately after spin convergence), basic target slip ratio of the drive wheels 5TAO in engine output control, drive in brake control The basic target slip ratio of the wheels 5TBO, the opening increase amount (backup opening) BUP during throttle valve opening increase control, and the forced return opening SM immediately after the first spin after starting slip control are set at the same step. FtlZZY control (
At the same time, the proportional constant KP and the integral constant in the feedback control of the throttle valve opening are set to 1 according to the zone, and the process returns.

Next, in the target slip ratio determination flow shown in FIG. 7, the basic target slip ratio 5TAO in engine output control and the basic target slip ratio 5TBO in brake control calculated based on the road surface μ estimation flow shown in FIG. 6 are corrected. This time, at step SDI, the accelerator pedal opening ACC
An accelerator pedal correction gain ACG that increases from the reference value (-1) is calculated in accordance with , and a vehicle speed correction gain VG that decreases from the reference value (-1) in accordance with the vehicle speed (driven wheel speed WPN) is calculated in step SD2. . Further, in step SD3, a steering angle correction gain STG is calculated that decreases from the reference value (-1) according to the steering operation amount (steering angle) ANC.

Then, in step So4, each basic target slip ratio 5TAOSSTBO is multiplied and corrected based on each of the above correction gains,
The calculation results are each set as STA%STB, and the process returns.

Next, the target throttle valve opening calculation flow shown in FIG. 8 will be explained. First, in steps SEI to SE3, the higher speed of the left and right driving wheel speeds WRR and WRL is set as the driving wheel speed SEn as a control target.

After that, in steps SE4 and Sε5, the drive wheel speed SEn
The slip rate S for the vehicle speed WPN is defined as the predetermined slip rate S
3 (e.g. S3-1.02), S4 (e.g. S4
= 1.01), and in the case of S>1.02, the throttle operation amount (increment) ΔTAGET is calculated by opening feedback control (PI-PD sub-control) in step SE6. On the other hand, 1.01> In the case of S, in order to gradually and forcibly increase the throttle valve opening degree by a predetermined value BUF (backup control), the predetermined value BUP obtained from the road surface μ estimation flow in FIG. 6 is set as the throttle operation amount in step SE7. Calculate as ΔTAGET.Furthermore, 1.02≧S
In the case of >1.01, the throttle operation amount ΔTAGET is calculated in step SE8 so as to perform control (buffer control) that smoothly transitions from the backup control to the feedback control.

Then, in step SE9, the current target throttle valve opening TAGETn is changed to the previous target throttle valve opening TAGE.
It is calculated as an added value of Tn-1 and the throttle operation amount ΔTAGET, and the process returns.

In the engine feedback control flow shown in FIG. 9, in step SFI, the target slip ratio STA in the engine control is multiplied by the vehicle speed WFN to calculate the target driving wheel speed STn, and in step SF2, the target driving wheel speed STn is calculated. The control deviation ENn is calculated by subtracting the current driving wheel speed SEn from the current driving wheel speed SEn.

Thereafter, the throttle operation amount ΔTAGET is calculated by the PI-PD sub-control in step SF3 using the proportional constants KP, PP, the integral constant Kl, and the differential constant FD, and the process returns.

Next, to explain based on the brake control flow shown in FIG. 10, in step SGI, first, an upper limit value BLM of the brake control amount is set in order to prevent a shock caused by a sudden increase or decrease in brake pressure.

After that, in order to control the right brake pressure among the left and right brake pressures, the slip ratio of the right drive wheel is set to 5 (-WRR/VP
N) is compared with a predetermined value Ss (for example, Ss -1,0625), and in the case of a small slip of S<1.0625, the brake control is stopped, and the brake control amount TBR of the right drive wheel is released in step SG3. (zero value), and in step SG4 the right brake flag BFR is set to BPR-3 (
(when open).

On the other hand, when there is a large slip of S≧1.0625, the brake control jilTBR for the right drive wheel is calculated by feedback control (PI-PD sub-control) in step sGs.

After that, in steps Sc and s, the spin flag 5P-1 (when only the right wheel spins) or 5P-3 (when both wheels spin) determines whether wheel spin (slip) has occurred in the right drive wheel 6. If wheel spin does not occur, a brake control flag FBP R indicating that brake control is in progress at the first wheel spin is set in step SG7.
Set to FBP R-0 (not under control).

On the other hand, when wheel spin occurs, step SCS ~
S G 12 is the wheel change speed ΔW of the speed of the right drive wheel 6
Only immediately after a spin occurs (initial stage of occurrence) (JP-1) where RR is equal to or higher than the set value (ΔWRR≧0), this spin is the first spin after the start of slip control (
MP-0), the brake control flag FBP
By setting R as FBP R-1, the brake control amount TBR at the initial stage of occurrence of the first spin is calculated in step S G13. Here, the brake control ff1T'sR at the initial stage of the first spin occurrence is determined to be a constant value regardless of the slip ratio S of the drive wheels 6. However, this brake control ff1
T'eR should be set to a larger value as the driving force of the driving wheels 6 (that is, the throttle valve opening and the gear ratio of the transmission) is larger, so as not to shock the vehicle due to excessive braking action. It is determined by the following formula.

T' s R-KT l-1・TAGETn-1+Ke
p and GP, where TAGETn-1 is the previous target throttle valve opening in slip control, KTH is a coefficient according to the throttle valve opening (the opening changes greatly), and C
P is the gear position, and KGP is a coefficient depending on the gear position CP (low gear changes greatly).

In addition, in steps S G +4 and S G +5, the brake control amount TBR at the initial stage of the first spin occurrence obtained above is
This brake control ff1T'sR is output to the brake actuator 21 only when the brake control amount TAR is greater than or equal to the brake control amount TAR by feedback control (T8R≦T'BR).

After that, in step SG16, if this brake control amount TBR is TBR>0, it is determined that the brake pressure is being increased (in particular, when TBR-0 is pressure holding), and in steps SG+7 and S c +s, this control amount is If TAR exceeds the upper limit value (maximum value of variation range) BLM, it is limited to the upper limit value BLM, and the right brake flag BFR is set to BPR-1 (at the time of pressure increase) in step S G19. On the other hand, if the brake control ff1TsR is 'r8 R<O, it is determined that the brake pressure is being reduced, and if this control amount TAR exceeds the lower limit value -BLM in steps 5G20 and S G 2+, it is limited to this lower limit value -BLM. Then, in step 5G22, the right brake flag BFR is set to BFR-2 (at the time of pressure reduction).

In addition, in step 5G23, in a situation where the brake pressure acting on the driving wheels 6 is higher than the set value, the value PR of the brake pressure acting on the driving wheels 6 is first determined in order to forcibly reduce or maintain the throttle valve opening. Estimation and calculation are performed based on the right brake pressure estimation flow shown in FIG.

After that, the brake control pressure TBL for the left driving wheel is calculated in step S G24 in the same manner as above.
Return.

Next, the right brake pressure estimation flow shown in FIG. 11 will be explained.

In steps 5t-II and 5t-12, the value of the right brake flag BPR is determined, and 13PR-1 (pressure increasing) and BP
In R-2 (during pressure reduction), the estimated brake pressure PR is calculated using the following formula % formula % in step SH3. Here, ΔPR is the change ΔPR−Ka−
TeR (Ks is the coefficient, TBR is the brake control amount)
. Then, in steps 5l-14 and SH5, the current estimated brake pressure PR is set to the previous value PRO, and the time elapsed T is initialized to 10, and the process returns.

On the other hand, when the brake pressure is not being increased or decreased, that is, when the brake is released, it is confirmed in step 5)46 that the estimated brake pressure PR is not approximately PR-0, and step S+-17 and St- Estimated brake pressure PR at +8
is calculated using the formula % formula %), the time elapsed T is measured, and the process returns.

Here, P91 is the brake pressure just before the brake is released, Tp
is the time constant of the hydraulic characteristics determined by the brake system, etc.

Furthermore, in step S's, the estimated brake pressure PR is approximately P.
In the case of R-0, the estimated brake pressure PR is set to PR=0 in steps S89 to 5H11, and this value PR is
is set as the previous value PRO, the time elapsed T is initialized to T-0, and the process returns.

Next, the target throttle valve opening correction flow shown in FIG. 12 will be explained. This correction flow corrects the throttle valve opening in order to prevent hunting of both, since the driving force acting on the driving wheels 6 is controlled by both engine output and brake pressure when controlling the slip of the driving wheels 6. It is something to control. In other words, if the throttle valve opening is opened during brake pressure increase, a hunting phenomenon occurs between the brake and the engine output, in which the increase in driving force caused by the opening is suppressed by the brake, so this is prevented. In addition, even if the brake is released, the brake pressure does not immediately reach the zero value, and if the throttle valve opening is opened during this time, a phenomenon similar to the above will occur, and when the brake pressure reaches the zero value, the throttle valve The opening degree is too wide, which will cause the drive wheels 6 to slip again, so if a brake pressure higher than a predetermined pressure is acting on the drive wheels 6, the opening degree of the throttle valve 10 is reduced or maintained. This is to perform correction control.

In other words, in steps Sr+ and SI2, when the vehicle is stuck (STF-1) or when traveling on a split road (SPF-1)
In this case, since it is necessary to increase the brake pressure and open the throttle valve opening, the throttle valve opening is not corrected and the spin state flag JP-0 (
When no spin occurs) and return.

Also, in steps SI4 and SIS, the left or right drive wheel 6
During brake pressure increase (BPI?-1 or BFL-1), the target throttle valve opening degree TAGETn in slip control of the drive wheels 6 is set to the previous value TAGET in step S16.
Step 3
17 and srs, except for JP-2 (immediately after spin convergence), that is, in the case of JP-i (immediately after spin occurs),
Set it again to JP-0 (when no spin occurs) and postpone the throttle valve opening recovery control (addition control of the predetermined opening FTAG in step SM16 in Fig. 3) immediately after the spin converges. Return.

Further, in steps SI9 to SI +2, the brake pressure is being reduced to the left or right drive wheel 6 (BF!?-2 or BFL-
2), or while the brake is released (BPR-3 or BFL-3
), steps S r 13 to S! 15, the estimated brake pressure PR or PL of the higher one of the left and right drive wheels 6
If exceeds the set minimum value Pm1n, in step S I 16, the current target throttle valve opening value TAGETn in slip control is set equal to the previous value TAGETn-1, and the opening is set to be maintained and decreased. ), then steps S I +7 and S I
18 when JP-2 (immediately after spin convergence) (that is, JP-
1 (immediately after spin occurs), the setting is reset to JP-0 (when spin does not occur), the recovery control of the throttle valve opening immediately after the spin converges is postponed, and the process returns.

Also, while the brake pressure of the left and right drive wheels 6 is being increased or decreased,
If it is not released, the spin state flag JP-0 (when no spin occurs) is set in step 5119, and the process returns.

Finally, the traction control termination determination flow shown in FIG. 13 will be explained.

First, in step 871, a target throttle valve opening ATAG corresponding to the accelerator pedal opening ACC is determined.

Thereafter, in step S12, the value of this target throttle valve opening ^TAG is determined, and if it is approximately ATAG-0, traction control is terminated, and steps SJ3 to
At SI5, each flag is reset, the output THR to the throttle actuator 12 is set to zero value, and this is set as the control target value TAGETn.

On the other hand, if ATAG≠00, the target throttle valve opening AT according to the accelerator pedal opening is further determined in step SJ6.
AG is the target throttle valve opening T in slip control.
Compare the size with AGETn, ^TAG > TAGEN
In this case, the slip control is continued, and in steps SJ7 and sys, if the target throttle valve opening TAGETn in this slip control is less than the control lower limit value (forced reduction opening value SM immediately after the first spin occurs), , after limiting to this lower limit value SH, this target throttle valve opening degree TAGETn is set as the output value THR to the throttle actuator 12 in step SJ9.

On the other hand, in the case of ATAG≦TAGETn, in order to control the throttle valve 10 with the target opening value ATAG corresponding to the depression degree of the accelerator pedal, this value ATAG is set as the output value THR in step SJ IG, and this is controlled. Target value TA
Let it be GETn.

Then, in step SJ12, the current control target value TA
Assuming GETn as the previous control target value TAGETn-1,
Return.

Therefore, steps SM9 to SM5 of the control flow in FIG.
According to M22 and the target slip rate determination flow in Fig. 7,
The target slip rate STA of the drive wheels 6 is the road surface μ, and the acceleration G1 of the vehicle is the accelerator pedal opening Acc.

The slip value (slip rate S) of the drive wheel 6 with respect to the road surface μ is determined based on a plurality of human power signals such as the vehicle speed WFN and the steering angle NG, and becomes the target slip rate (target value) STA of the drive wheel 6. First, set the target throttle valve opening TAGETn and brake control ff1TB,
Next, the opening degree of the throttle valve 1o is set to this target value TACET.
A control means 23 is configured to control the operation of the throttle actuator 12 and the brake actuator 21 so that the brake force applied to the drive wheels 6 is increased by the brake control ff1Te.

In addition, in the brake pressure control flow shown in FIG. 10, in steps Sc6 and Scs to Sc+s, at the initial stage of occurrence of the first spin after the start of slip control, the driving wheel speed change rate Δνl? R is greater than or equal to the set value O (ΔνRR≧ru)
Regardless of the slip rate S of the driving wheels 6, the driving wheels 6
Brake control with a constant value commensurate with the driving force of ff1T
'BR is calculated, and the brake actuator 21 is operated with the set brake control amount T'8R so that a sufficiently large braking torque of a predetermined value is temporarily applied to the driving wheels 6 for this period (ΔWI?I?≧ω). This constitutes an initial braking force control means 24 that controls the operation of the braking force.

Therefore, in the above embodiment, as shown in FIG. 14, after the slip control of the drive wheels 6 is started, the drive wheels 6
As the rotation speed increases, its slip rate S increases as shown by symbol A.
When S exceeds the spin judgment value 81 and the first slip occurs in the driving wheels 6, the opening of the throttle valve 10 reaches the small opening value S.
S<S
After returning to +, the return control is performed by the recovery opening value FTAG, and then feedback control (PI-PD control) of the drive wheels 6 is performed. In order to prevent the drive wheel slip rate S from significantly decreasing below the target value STA, buffer control and backup control are performed in sequence, and when the rotation speed of the drive wheels begins to increase, the buffer control is thereafter performed. After that, feedback control (Pi-PD control) is performed again, and as a result, the slip ratio S of the drive wheels 6 satisfactorily converges to the target slip ratio STA.

Then, the accelerator pedal depression degree decreases, and the target throttle valve opening degree ATAGn corresponding to the accelerator pedal becomes less than or equal to the target throttle valve opening degree TAGET, n of slip control (A
Symbol B is shown in the same figure when the situation is TAGn≦TAGETn).
After the time indicated by , the throttle valve opening degree is controlled to the target throttle valve opening degree ATAG corresponding to the accelerator pedal, and the slip control of the drive wheels 6 is stopped when the accelerator pedal 11 is fully opened. The above is the operation of controlling only the throttle valve opening degree in the slip control of the drive wheels 6.

Next, the characteristic operation of the present invention will be explained. Now, as shown in FIG. 15, when the rotational speed of the drive wheel 6 increases and its slip ratio S exceeds the spin determination value Sl, and the first slip occurs in the drive wheel (state indicated by symbol A), The opening of the throttle valve 10 is controlled by the control means 23, and as in the above basic operation, the opening is initially set to a small opening value (TAGETn-88).
When the spin converges, the cover opening degree P decreases instantaneously to
Increases by TAC, then throttle operation amount ΔTAG
Only the ETT is feedback controlled. At the same time, conventionally, although a braking force is applied to the drive wheels 6 as shown by the broken line, the brake control amount TAR is initially small and becomes large when the rotation speed of the drive wheels 6 approaches the maximum. Due to the response delay, the rotational speed of the drive wheels 6 does not decrease immediately, and it takes time to converge to the target slip ratios S and rA. However, in the present invention, even at the beginning of the slip control, a sufficiently large brake control amount T'BR of a predetermined value corresponding to the driving force of the driving wheels 6 acts immediately as shown by the solid line, and this causes -temporal ( (WRR≧2), the rotational speed of the drive wheels 6 can be quickly reduced with a small braking force, and the rotational speed of the drive wheels 6 can be favorably converged to the target slip ratio STA in a short time.

Note that after the brake control amount T'BR of the predetermined value temporarily acts, the brake control amount TB due to feedback control
Even if the brake pressure is reduced for the first time after the slip of the driving wheels 6 is converged due to this, if the brake pressure exceeds the set minimum value Pm1n, the spin state flag JP is set to JP. -1 (immediately after spin occurs)
Since the setting is forcibly reset to JP-0 (no spin occurring) and the throttle valve opening degree recovery control is prohibited, hunting between the brake pressure and the engine output can be prevented.

In addition, during slip control, if a second or subsequent slip occurs in the driving wheels 6, the throttle valve opening is gradually decreased under feedback control (PI-PD control) as shown in FIG. , the brake pressure also gradually increases from zero due to feedback control, unlike during the first spin.In this case, the brake pressure begins to decrease immediately after the slip of the drive wheels 6 converges, and the speed of the drive wheels 6 temporarily reaches the target value. When the target throttle valve opening starts to change to the opening side even if the brake pressure is still decreasing, the opening of the throttle valve 10 also starts to open as shown by the broken line in the figure, and the engine output increases. Hunting occurs between the brake pressure and the engine output, and when the brake pressure reaches zero value, the throttle valve opening is too large and the drive wheel 6 is damaged as shown by the broken line in the figure.
This may result in a re-slip. However, in this embodiment, the brake pressure PR is the set minimum value! Since the target throttle valve opening TAGETn is controlled to be maintained or decreased until it becomes "sin," hunting as described above is prevented, and re-slip of the drive wheels 6 can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 16 show embodiments of the present invention, in which FIG. 2 is a general schematic diagram, FIGS. 3 to 13 are flowcharts showing slip control of drive wheels by the controller, and FIGS. FIG. 16 is an explanatory diagram of the operation. DESCRIPTION OF SYMBOLS 1... Engine, 6... Driving wheel, 10... Throttle valve, 11... Accelerator pedal, 12... Throttle actuator, 20... Controller (control device), 21... Brake actuator , 22...
Drive torque adjustment means, 23...control means, 24...
Initial braking force control means. Patent applicant Mazda Corporation Figure 5 Figure 6 Figure 8 Figure 7

Claims (1)

[Claims] (1) A drive torque adjustment means for adjusting the drive torque acting on the drive wheels; and the drive torque adjustment so that the slip value of the drive wheels with respect to the road surface becomes a predetermined target value determined based on a plurality of input signals. In the slip control device for an automobile, the braking torque of a predetermined value is temporarily applied to the drive wheel regardless of the slip value of the drive wheel at the beginning of the slip control of the drive wheel. A slip control device for an automobile, comprising an initial braking force control means for controlling the braking force of the drive torque adjusting means.