JPH07228237A - Traction control device for vehicle - Google Patents

Abstract

PURPOSE:To enhance traveling stability, and secure braking force when both a brake pedal and an accelerator pedal are operated by continuing brake traction control even when the brake pedal is actuated. CONSTITUTION:In traction control containing engine traction control and brake traction control, on the assumption that an attached letter [E] shows an engine and an attached letter [B] shows a brake, operation (S21) is performed on objective slip quantity standard values SETo and SBTo from a map, and operations (S22 and S23) are performed on a factor KD to correct the standard values SETo and SBTo according to a traveling condition, and when a brake switch is turned off, objective slip quantities SET and SBT are respectively set (S25) by multiplying the standard values SETo and SBTo by the factor KD, and when the brake switch is turned on, the target slip quantities SET and SBT are respectively set (S26) by multiplying the standard values SETo and SBTo by the factor KD and a specific value (alpha) of (0<alpha<1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traction control device for a vehicle, and more particularly to a device for continuing brake traction control even when a brake pedal is depressed.

[0002]

2. Description of the Related Art Conventionally, in order to prevent the driving wheels from slipping due to excessive driving torque and deteriorating the running performance during acceleration of a vehicle, a slip ratio or a slip amount of the driving wheels (this is called a slip value). ) Is detected and the engine driving force and the braking force for the wheels are controlled (the engine driving force is reduced or the braking force is increased) so that the slip value of the driving wheel becomes the target slip value. Traction control technology has been generally put to practical use.

In this type of vehicle traction control, a wheel speed sensor for detecting the wheel speed of each of the four wheels is provided, and the slip value of the drive wheel is calculated from the drive wheel wheel speed and the driven wheel wheel speed. The target slip value is set according to the vehicle body speed determined from the wheel speed of the passive wheels and the road surface friction coefficient. Then, the road surface friction coefficient is estimated from the wheel speed of the passive wheel and its acceleration (see Japanese Patent Laid-Open No. 60-99757). In order to suppress the slip of the drive wheels, retardation of ignition timing and / or fuel cut, or adjustment of intake air amount through an auxiliary throttle valve in the intake passage is applied as a technique for suppressing engine drive force. To be done.

As a technique for controlling the braking force, it is general to operate a braking device for driving wheels. However, in view of durability of the braking device, when the slip value is small, the engine is driven by engine traction control. A traction control technique has also been proposed in which the braking force is increased by the brake traction control while reducing the force and, when the slip value is large, reducing the engine driving force (see Japanese Patent Laid-Open No. 63-166649).

Japanese Patent Laid-Open No. 62-166151 discloses a vehicle in which traction control including engine traction control and brake traction control and anti-skid brake control can be executed, and slip occurs due to traction control during acceleration. In addition, the wheel lock is suppressed by the anti-skid brake control during braking, and when both the brake pedal and the accelerator pedal are operated, the brake traction control is prohibited and only the engine traction control is permitted. The vehicle slip control device configured as described above is described.

On the other hand, in order to detect the depression of the brake pedal, a brake switch is provided in the vicinity of the brake pedal. Normally, this brake switch is switched from OFF to ON when the brake pedal moves a little. It is set. Traction control is a control for suppressing slip during acceleration of the vehicle, and braking by operating the brake pedal is intended for deceleration, so in the conventional traction control device, in general, As described in the above publication, the brake traction control is prohibited during braking, that is, when the brake switch is turned on.

[0007]

As described above, when the brake traction control is prohibited when the brake switch is turned on, the left foot is erroneously placed on the brake pedal during execution of the brake traction control. When the brake switch is turned on by touching, or when the brake pedal vibrates due to the vibration caused by traveling and the brake switch repeatedly turns on and off, the brake traction control is prohibited and the running brake traction control is Since it is immediately stopped, it is not preferable for ensuring running stability.

However, if the brake traction control is allowed even during braking by operating the brake pedal, a panic state occurs in a panic during an emergency during running, and when the brake pedal and the accelerator pedal are simultaneously operated, for example. However, there is a problem that the braking force cannot be strengthened sufficiently. It is an object of the present invention to continue the brake traction control even when the brake pedal is actuated to improve the running stability and to secure the braking force when both the brake pedal and the accelerator pedal are operated. Is to provide a control device

[0009]

According to a first aspect of the present invention, there is provided a traction control device for a vehicle and a brake traction control means for performing brake traction control on a braking means in order to suppress a slip of a drive wheel on a road surface. On the other hand, in a traction control device for a vehicle including engine traction control means for performing engine traction control, pedal operation detection means for detecting operation of a brake pedal is provided, and the brake traction control means uses the pedal operation detection means for the brake pedal. When the operation of the brake pedal is detected, the brake traction control which is being executed before the operation of the brake pedal is detected is continued, and when the operation of the brake pedal is detected by the pedal operation detecting means, the brake traction control is performed. Control At least for use in the control amount setting
Condition changing means for changing one physical quantity in the braking promoting direction is provided.

Here, the condition changing means may be configured to change the target slip value as the physical quantity to a smaller value (claim 2 dependent on claim 1). Further, an end condition changing means for changing the engine traction control end condition to the end promoting direction may be provided when the operation of the brake pedal is detected by the pedal operation detecting means (claim 1 or claim 2). Dependent claim 3).

[0011]

In the traction control device for a vehicle according to the first aspect of the present invention, the brake traction control means, when the operation of the brake pedal is detected by the pedal operation detecting means, before the operation of the brake pedal is detected. The condition changing means is configured to continue the running brake traction control, and the condition changing means, when the operation of the brake pedal is detected by the pedal operation detecting means, accelerates at least one physical amount used for setting the control amount of the brake traction control. Change to the direction. Therefore, even if the brake pedal is activated due to an erroneous operation on the brake pedal or the vehicle vibration, the brake traction control being executed is continued and the brake traction control is changed to the braking promoting direction, so the brake traction control is immediately stopped. It is possible to eliminate a decrease in traveling stability that accompanies this, and to prevent a decrease in braking force when the brake pedal and the accelerator pedal are simultaneously operated in the panic state.

In the traction control device for a vehicle according to a second aspect of the invention, the condition changing means changes the target slip value as the physical quantity to a small value, so that the brake traction control is surely changed to the braking accelerating direction. Power can be increased. The traction control device for a vehicle according to claim 3, wherein when the operation of the brake pedal is detected by the pedal operation detecting means, the end condition changing means for changing the engine traction control end condition in the end promoting direction is provided. The termination of the engine traction control when the pedal operation is detected can be promoted.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is an example of applying the present invention to a traction control device for a rear-wheel drive type vehicle. As shown in FIG. 1, in this vehicle,
The left and right front wheels 1 and 2 are driven wheels, and the left and right rear wheels 3 and 4 are drive wheels. From the automatic transmission 6 including the gear mechanism to the propeller shaft 7,
It is configured to be transmitted to the left and right rear wheels 3 and 4 via the differential device 8 and the left and right rear wheel drive shafts 9 and 10.

A surge tank 12 connected to an intake pipe 11 is disposed above the left and right banks of the engine 5, and each of the six branch intake pipes 13 has a surge tank 12 therein.
Is connected to the intake port of the bank on the opposite side extending from the side portion of each of the branch intake pipes 13, and an injector 14 for injecting fuel into the branch intake pipe 13 or the intake port is attached to each branch intake pipe 13.
The intake pipe 11 is provided with a main throttle valve 16 interlocked with an accelerator pedal 15 and a sub-throttle valve 17 arranged upstream thereof, and an actuator 18 for rotating the sub-throttle valve 17 is provided. There is. The left and right front wheels 1 and 2 and the rear wheels 3 and 4 are supplied with brake hydraulic pressure and disks 21a to 24a that rotate integrally with the wheels.
Brake devices 21 to 24 including calipers 21b to 24b for braking the rotation of the disks 21a to 24a are provided, respectively, and a brake control system for operating these brake devices 21 to 24 is provided.

In this brake control system, the driver's stepping force on the brake pedal 25 is boosted by the booster 26, and the brake hydraulic pressure pressurized from the booster 26 is supplied to the tandem master shilling 27. . Front wheel braking pressure supply pipe 2 extending from the master shilling 27
8 and 29 are brake devices 21 and 22 for the left and right front wheels 1 and 2.
Are connected to the calipers 21b and 22b, respectively.

Regarding the brake hydraulic pressure supply system for the left and right rear wheels 3, 4, a braking pressure supply pipe 30 extending from the booster 26 is provided on the way to the left rear wheel braking pressure supply pipe 34 and the right rear wheel braking pressure supply pipe. 35, and the left rear wheel braking pressure supply pipe 34 and the right rear wheel braking pressure supply pipe 35 are connected to the calipers 23b and 24b of the brake devices 23 and 24 of the left and right rear wheels 3 and 4, respectively. There is. An electromagnetic opening / closing valve 31 is connected to the braking pressure supply pipe 30, and a check valve 33 that allows the brake hydraulic pressure to be supplied from the booster 26 is connected to a hydraulic pressure supply pipe 32 in parallel with the electromagnetic opening / closing valve 31. Has been done.

An electromagnetic opening / closing valve 36 is provided in a left rear wheel braking pressure supply pipe 34 leading to the brake device 23 of the left rear wheel 3.
The left rear wheel braking pressure supply pipe 3 is provided downstream of the on-off valve 36.
4 is a relief passage 38 in which an electromagnetic opening / closing valve 37 is attached.
Are connected. An electromagnetic opening / closing valve 39 is interposed in the right rear wheel braking pressure supply pipe 35 communicating with the brake device 24 of the right rear wheel 4, and an electromagnetic opening / closing valve 39 is provided on the downstream side of the opening / closing valve 39. A relief passage 41 to which the on-off valve 40 is attached is connected. In addition, the solenoid on-off valves 36, 37,
39 and 40 are configured to be driven via a duty solenoid.

Further, the oil in the reservoir tank 42 is pumped by the pump 4
The hydraulic pressure pressurized in 3 is applied to the booster 26 by the hydraulic pressure supply pipe 44.
The hydraulic supply pipe 45 is connected to the branch portion 48 from the downstream side of the pump 43 of the hydraulic supply pipe 44, and the electromagnetic opening / closing valve 46 is provided in the hydraulic supply pipe 45.
The oil overflowing from the booster 26 is returned to the reservoir tank 42 by the return pipe 47. Further, the left rear wheel braking pressure supply pipe 34 is connected with a hydraulic pressure sensor 55 for detecting the hydraulic pressure, and the right rear wheel braking pressure supply pipe 35 is connected with a hydraulic pressure sensor 56 for detecting the hydraulic pressure. There is. However, the hydraulic pressure sensors 55 and 56 may be omitted.

A wheel speed sensor 51 for detecting a wheel speed V1 of the left front wheel 1, a wheel speed sensor 52 for detecting a wheel speed V2 of the right front wheel 2, and a wheel speed sensor 53 for detecting a wheel speed V3 of the left rear wheel 3. A wheel speed sensor 54 for detecting the wheel speed V4 of the right rear wheel 4, a steering angle sensor 58 for detecting the steering angle of the steering wheel 57, and a brake switch 59 that is turned on when the brake pedal 25 is operated (this is the pedal (Corresponding to operation detecting means), an engine speed sensor 61, an accelerator sensor 62 for detecting the depression amount of the accelerator pedal 15, and a throttle sensor 6 for detecting the opening of the main throttle valve 16.
3. Sensors such as a mode switch 64 for setting a running mode (sport mode, normal mode, safety mode) are provided, engine traction control for the engine 5, and brake devices 23, 24 for the left and right rear wheels 3, 4 are provided. A traction control device 50 is provided for performing brake traction control for the vehicle.

Each of the wheel speed sensors 51 to 54 has a structure in which a plurality of detecting portions formed on the brake disks 21a to 24a or in the vicinity thereof are detected by an electromagnetic pickup. Detection signals from the sensors and switches are supplied to the traction control device 50. A control signal for engine traction control is supplied from the traction control device 50 to the engine control device 60, and the electromagnetic opening / closing valves 31, 46, 3 are also provided.
A control signal for brake traction control is supplied to 6, 37, 39 and 40. It should be noted that the engine control device 60 uses the actuator 1 based on the control signal of the traction control.
The sub-throttle valve 17 is controlled via 8.

The traction control device 50 has a waveform shaping circuit for shaping the detection signals from the sensors and switches as necessary, an A / D converter for AD-converting the detection signals as necessary, and an input output. Interface, microcomputer, solenoid valve 31, 46, 36, 3
7, 39, 40 and a drive circuit for the actuator 18, a plurality of timers, etc., the ROM of the microcomputer stores in advance control programs for traction control, tables, maps, etc., and various types of RAM. Work memory is provided.

The brake control will be briefly described. When the brake traction control is not executed,
When the electromagnetic opening / closing valve 31 is opened and the electromagnetic opening / closing valve 46 is closed,
The brake hydraulic pressure is supplied from the booster 26 to the brake devices 21 to 24 during braking. At the time of brake traction control, the electromagnetic on-off valve 31 is closed, the electromagnetic on-off valve 46 is opened, and the electromagnetic on-off valves 36, 37, 39, 40 are duty-controlled as appropriate, so that the brake devices 2 for the left and right rear wheels 3, 4 are controlled.
The brake hydraulic pressures of 3 and 24 can be controlled to desired pressures.

Next, traction control including engine traction control and brake traction control executed by the controller 50 will be described with reference to the drawings starting from FIG. 2. First, an outline of this traction control will be described. I will explain. The target slip amount of the drive wheels 3 and 4 (target slip amount for throttle control, target slip amount for brake control) is set according to the running state of the vehicle and the road friction state, and the slip amount of the drive wheels 3 and 4 is set. It is calculated using the wheel speeds of the four wheels, and the auxiliary throttle valve 17 is controlled so that the slip amount is equal to or less than the target slip amount for throttle control when the vehicle is accelerating.
The brake devices 23, 24 are controlled via the electromagnetic on-off valves 36, 37, 39, 40 so that the slip amount becomes equal to or less than the brake control target slip amount.

Next, the main routine of traction control will be described with reference to the flow charts of FIGS. In the figure, reference numeral Si (i = 1, 2, 3 ...) Shows each step, and this main routine is repeatedly executed at every predetermined minute time (for example, 10 ms).

In FIG. 2, when control is started by starting the engine, slip amount detection processing is executed (S
1) Next, a target slip amount setting process is executed (S
2) Next, a slip determination process is executed (S3), and then a target control amount calculation process for throttle control is executed (S).
4) Next, a target control amount calculation process for brake control is executed (S5), and then a slip flag F for throttle control is applied.
A control signal for throttle control is output to the engine control device 60 on condition that e = 1 (S6), and then the left rear wheel 3
Of the brake control slip flag Fb1 = 1, the left rear wheel brake control control signal is output, and
On condition that the brake control slip flag Fb2 of the right rear wheel 4 is Fb2 = 1, a control signal for the right rear wheel brake control is output (S7), and then the process returns.

Next, each subroutine of S1 to S5 will be described. Slip amount detection process ... See FIG. 3. When the subroutine of this slip amount detection process is started, first, the wheel speeds V1 to V1 of the left and right front wheels 1 and 2 and the rear wheels 3 and 4 are set from the wheel speed sensors 51 to 54. V4 is read (S10), then the vehicle speed V, which is the vehicle body speed, is calculated as the average value of the left and right driven wheel speeds V1 and V2, and the maximum drive wheel speed Vm is calculated from the left and right drive wheel speeds V3 and V4. It is calculated as the maximum value (S11). Next, in S12, the slip amount Se for throttle control, the slip amount Sb1 for left rear wheel brake control, and the slip amount Sb2 for right rear wheel brake control are calculated by the equations shown in the drawing, and the data of these slip amounts are stored in the work memory. It is stored while updating to.

Target Slip Amount Setting Process (See FIG. 4) When the target slip amount setting process subroutine is started, various signals (road surface friction coefficient μ,
The vehicle speed V, the accelerator depression amount, the detected steering angle θ, the mode signal from the mode switch 64, the brake switch signal from the brake switch 59, etc.) are read (S20).
Here, the road surface friction coefficient μ is calculated as follows based on the vehicle speed V and its acceleration Vg by an interrupt processing routine (not shown), and is updated every moment. To calculate the road friction coefficient μ, a timer of 100 ms count and 5
500ms that the vehicle body acceleration Vg does not become sufficiently large from the start of slip control by using a timer with a count of 00ms
Until the passage of time, the vehicle body acceleration Vg is calculated from the change of the vehicle speed V for 100 ms every 100 ms by the following equation (1), and
After the lapse of 500 ms when the vehicle body acceleration Vg becomes sufficiently large, the vehicle body acceleration Vg is calculated by the following equation (2) from the change of the vehicle speed V for 500 ms every 100 ms. Incidentally, V
(I) is now, V (i-100) is 100 ms ago, V
(I-500) is each vehicle speed before 500ms, K1, K
2 is a predetermined constant. In addition, ms means msec.

Vg = K1 × [V (i) -V (i-100)] (1) Vg = K2 × [V (i) -V (i-500)] (2) The road surface friction coefficient μ is The vehicle speed V obtained as described above,
It is calculated by three-dimensional complementation from the μ table shown in Table 1 using the vehicle body acceleration Vg, and stored in the work memory while being updated.

[0029]

[Table 1]

Next, in S21, the map M0 shown in FIG.
By applying the road surface friction coefficient μ to the throttle control target slip amount basic value SETo and the brake control target slip amount basic value SBTo. As shown in the map M0, the basic value SETo is set smaller than the basic value SBTo because the engine traction control suppresses the slip when the slip amount is small and the engine traction is large when the slip amount is large. This is to prevent the load on the brake devices 23 and 24 from increasing by suppressing the slip by the control and the brake traction control.

Next, in S22, the basic value SETo
And the basic value SBTo are calculated as coefficients k1 to k4 for correcting the basic value SBTo according to the traveling state of the vehicle. That is, the coefficient k1 is calculated by applying the vehicle speed V to the map M1 in FIG.
The coefficient k2 is calculated by applying the accelerator depression amount to the map M2 of FIG. 11 and the coefficient k2 is calculated by applying the steering angle θ to the map M3 of FIG.
3 is calculated, and the coefficient k4 is calculated from the map M4 of FIG. 12 and the mode signal. Next, in S23, the coefficient KD obtained by multiplying the coefficients k1 to k4 is calculated, and then S
24, it is determined whether or not the brake switch 59 is OFF, and when the determination is Yes (when the brake pedal 25 is not operating), the target slip amount SET for throttle control is SET = basic in S25. Value SETo ×
The target slip amount S for brake control is calculated as KD.
BT is calculated as SBT = basic value SBTo × KD, and these are stored in the work memory.

On the other hand, when the brake switch 59 is ON, in S26, the throttle control target slip amount SET is calculated as SET = basic value SETo × KD × α, and the brake control target slip amount SBT is SBT = basic. The value SBTo * KD * [alpha] is calculated, and these are stored in the work memory. Note that α is a predetermined constant of 0 <α <1 (for example, α = 0.5). Thus, the reason why the throttle control target slip amount SET and the brake control target slip amount SBT are set to be small when the brake switch 59 is ON is to promote braking.

Slip determination process: See FIG. 5. When the slip determination process is started, various signals (slip amounts Se, Sb1, Sb2, target slip amount SET, SBT data, brake switch signal, etc.) are read. (S3
0) and then, in S31 to S37, a slip flag Fe for identifying the necessity of engine traction control,
A slip flag Fb1 for identifying the necessity of brake traction control for the brake device 23 of the left rear wheel 3 and a slip flag Fb2 for identifying the necessity of brake traction control for the brake device 24 of the right rear wheel 4 are set.

In S31, it is determined whether Se> SET or not. When the determination is Yes, the slip flag Fe is set to 1 in S32, and then the process proceeds to S37. When the determination in S31 is No, it is determined in S33 whether the brake switch 59 is OFF, and the determination is
If Yes, the process proceeds to S34, and the determination in S33 is
If No, the process proceeds to S35. In S34,
Se ≦ SETo × KD × β = SETs (engine control target slip amount end threshold value) for a predetermined time Δ (for example,
(Δ = 1000ms) It is judged whether or not it continues, and the judgment is
If Yes, the slip flag Fe is reset to 0 in S36. However, the determination of continuation for the predetermined time is actually made by setting a flag (not shown) and timing by a timer (not shown). If the determination in S34 is No, the process proceeds to S37. The above β
Is a predetermined constant of 0 <β <α (for example, β = 0.2 to 0.3).
).

On the other hand, when the determination in S33 is No, that is, when the brake switch 59 is ON, in S35,
It is determined whether the condition Se ≦ SETo × KD × β = SETs continues for a predetermined time δ (eg, δ = 500 ms). If the determination is Yes, the slip flag F is determined in S36.
e is reset to 0. However, the determination regarding the continuation of the predetermined time is actually performed by setting a flag (not shown) and timing by a timer (not shown). However, when the brake switch 59 is ON, δ is set to a value of about 1/3 to 1/2 of Δ in order to accelerate the end of the traction control. Next, in S37, when Sb1> SBT, the slip flag Fb1 is set to 1, and
When Sb1 ≦ SBT, the slip flag Fb1 is reset to 0. Then, when Sb2> SBT, the slip flag Fb2 is set to 1, and when Sb2 ≦ SBT, the slip flag Fb2 is reset to 0.

Target control amount calculation process for throttle control
・ Refer to FIG. 6. When this calculation process is started, various signals (slip amount S
e, the target slip amount SET, the slip amount deviation EN (i-1) of the slip amount Se from the target slip amount SET, the engine speed Ne, the throttle opening TVO of the main throttle valve 16,
The final target control amount FTetg (i-1), slip flag Fe, vehicle speed V, and other data) are read (S40). However, the subscript (i-1) indicates the previous value and the subscript (i) indicates the current value.

Next, in S41, the slip amount deviation E
N and the current deviation EN (i) is calculated as the difference between the slip amount Se and the target slip amount SET, and the slip amount deviation change rate DEN is the deviation change rate DEN (i) at this time. It is calculated as the difference between the deviation EN (i) and the previous deviation EN (i-1). Next, in S42, the deviation EN (i) and deviation change rate DEN (i) of this time are applied to Table 2, and the basic control amount basic value T
eo is calculated, and the basic control amount basic value Teo is shown in Table 3.
Then, the basic control amount basic value Teo is digitized.

[0038]

[Table 2]

[Table 3]

Table 2 shows the engine traction control.
In the table, ZO indicates holding of the opening of the auxiliary throttle valve 17, N indicates closing of the auxiliary throttle valve 17, P indicates opening of the auxiliary throttle valve 17, and subscripts S, M, B.
Indicates the magnitude of the control amount, and S is “small control amount”,
M indicates "medium control amount" and B indicates "large control amount". The table in Table 3 is a numerical representation of the controlled variable in the table in Table 2, and the numerical value in Table 3 is the speed (% / s) for opening and closing the sub throttle valve 17.

Next, in order to correct the control amount in accordance with the operating state of the engine, in S43, the engine speed Ne and the throttle opening TVO are applied to Table 4, and the correction coefficient K is applied.
e is calculated, and the basic control amount basic value Teo × Ke is set as the basic control amount Te (i) of this time.

[0041]

[Table 4]

Next, at S44, the final target control amount FTegt (i) of this time is set to a value obtained by adding the basic control amount Te (i) of this time to the last target control amount FTegt (i-1) of the previous time. It Next, in S45, the previous slip flag Fe (i-1)
= 0, and whether or not the slip flag Fe (i) = 1 this time,
In other words, it is determined whether or not a series of engine traction control execution states have been entered this time, and if the determination is Yes,
In S46, the vehicle speed V and the road surface friction coefficient μ are applied to the map M5 of FIG. 13 to calculate the initial closing motion amount SM of the sub-throttle valve 17, and the final target control amount FTe of this time.
tg (i) is set to γ × SM. It should be noted that γ is a predetermined positive constant. If the determination in S45 is No,
S46 is skipped.

Target control amount calculation process for brake control ...
When the target control amount calculation process is started, various signals (slip amounts Sb1 and Sb2, target slip amount SBT, slip amounts Sb1 and Sb2 of the slip amount deviation ENb1 (i-1 ), ENb2 (i-1), final target control amount FTb
Data such as tg1 (i-1) and FTbtg2 (i-1)) are read (S50). The subscript "1" indicates the brake device 23 and the electromagnetic on-off valves 36, 37 of the left rear wheel 3, and the subscript "2" indicates the brake device 24 and the electromagnetic on-off valves 39, 40 of the right rear wheel 4.

Next, in S51, the slip amount deviation E
N is the deviations ENb1 (i) and ENb2 (i) of this time, and the slip amount deviation change rate DEN is the deviation change rate DENb1 (i) of this time.
, DENb2 (i) are calculated in the same manner as described above according to the calculation formula shown. Next, in S52, the current slip amount deviation ENb1 (i) and the current slip amount deviation change rate DENb1
(i) is applied to the table in Table 2 to calculate the basic value Tb1 (i) of the present basic control amount, and the slip amount deviation ENB2 (i) of this time and the slip amount deviation change rate DENb2 ( i)
Is applied to the table of Table 2 to calculate the basic value Tb2 (i) of the present basic control amount. Next, the basic control amount basic value T
b1 (i) and Tb2 (i) are applied to the table of Table 5, respectively, and these are digitized (S53).

[0045]

[Table 5]

The numerical values in Table 5 excluding the positive and negative signs are the duty ratios (%) of the duty solenoids of the solenoid on-off valves 36, 37, 39 and 40. The duty ratio of 39 and the duty ratio of the solenoid opening / closing valves 37 and 40 at the time of pressure reduction are shown. When increasing the pressure, the solenoid on-off valves 37 and 40 are fully closed (duty ratio =
0), and when the pressure is reduced, the solenoid on-off valves 36, 3
9 is set to be fully closed (duty ratio = 0). Then S
At 54, the final target control amounts FTbtg1 (i), FTbtg for this time
2 (i) is the basic control amount basic values Tb1 (i), Tb2 (i) of the present final target control amount FTbtg1 (i-1), FTbtg2 (i-1) ) Is set as the value added respectively.

When the final target control amount FTetg (i) for engine traction control and the final target control amounts FTbtg1 (i), FTbtg2 (i) for brake traction control are calculated as described above, S6 of the main routine is calculated. , The final target control amount FTetg is set on condition that the slip flag Fe = 1.
A control signal corresponding to (i) is output to the engine control device 60, and then, in S7, the electromagnetic opening / closing valves 36 and 37 for the brake device 23 of the left rear wheel 3 are provided on condition that the slip flag Fb1 = 1. On the other hand, a control signal corresponding to the final target control amount FTbtg1 (i) is output, and on the condition that the slip flag Fb2 = 1, the electromagnetic on-off valves 39 and 40 for the brake device 24 of the right rear wheel 4 are supplied. The final target control amount F
The control signal corresponding to Tbtg2 (i) is output.

Next, the operation of the traction control described above will be described. As shown in the time chart of FIG. 14, until the time t1, the drive wheels 3 and 4 do not have a large slip and the engine traction control is not in the execution state. Therefore, the sub throttle valve 17 is set to the fully open state. Has been done. When the amount of depression of the accelerator pedal 15 increases and the slip amount Se becomes larger than the target slip amount SET at the time point t1, the engine traction control execution state is entered, and the opening degree of the sub throttle valve 17 at this time point becomes The initial closing motion amount SM is closed at once, and thereafter, the opening degree of the sub-throttle valve 17 is feedback-controlled so that the slip amount Se becomes the target slip amount SET.

At time t2, the slip amounts Sb1 and Sb2
However, since it becomes larger than the target slip amount SBT, the brake traction control execution state is entered, and the left and right rear wheels 3,
4, the electromagnetic on-off valves 37, 40 of the braking devices 23, 24 of No. 4 are closed, the duty ratio of the electromagnetic on-off valves 36, 39 is increased, and control to increase the brake hydraulic pressure is started. Both engine traction control and brake traction control are started. Is executed. After that, the brake oil pressure is maintained,
At time t3, the slip amounts Sb1 and Sb2 become equal to or less than the target slip amount SBT, so the electromagnetic opening / closing valves 36 and 39 are closed, the duty ratio of the electromagnetic opening / closing valves 37 and 40 is increased, and the brake hydraulic pressure is reduced. .

Here, regarding the engine traction control, at the time point t1, the sub-throttle valve 17 is closed by the initial closing amount SM.
Even if all of them are closed at once, the slip amount Se rapidly increases. At this time, since the slip amount deviation EN and the deviation change rate DEN are large values on the (+) side, for example, "NB" is set as the basic control amount basic value, and as a result, the sub throttle valve 17 rapidly moves. It was closed, and then
"NM", "NS", "Z" as basic control amount basic values
“O” is sequentially calculated, the closing movement of the sub-throttle valve 17 is gradually eased and then tends to be held, the slip amount Se decreases, and then the deviation change rate DEN becomes a large value on the (−) side. Therefore, “PS” is set as the basic control amount basic value, and the slip amount Se converges on the target slip amount SET while the sub-throttle valve 17 is driven to the opening side.

Here, in the brake traction control of the traction control of this embodiment, as shown in FIG. 5, when the slip flags Fe, Fb1, Fb2 are set, the brake switch 59 is turned on. Also, the slip flags Fe, Fb1, Fb2 are held in the set state, that is, even if the brake switch 59 is turned on, both engine traction control and brake traction control are continued. Then, as shown in S24 to S26 of FIG. 4, when the brake switch 59 is turned on, compared to when the brake switch 59 is turned off,
Since the target slip amount SET for throttle control and the target slip amount SBT for brake control are changed to a small value, the final target slip amounts FTBtg1 (i), FTBtg2 (i) for brake traction control are braked when the brake switch 59 is ON. The direction of promotion is changed.

Therefore, when the brake pedal is actuated and the brake switch 59 is turned on by an erroneous operation, or when the brake pedal is actuated and the brake switch 59 is turned on by the vibration of the vehicle body during traveling on a bad road. In addition, since the engine traction control and the brake traction control that are being executed are continued without being immediately stopped, it is possible to prevent the traveling stability from being deteriorated due to the sudden stop of the traction control. Moreover, even if the driver panics in an emergency and operates the accelerator pedal 15 and the brake pedal 25 at the same time by mistake, the final target slip amounts FTBtg1 (i), FTBtg2 (i) are braked as described above. Since the braking force can be strengthened by changing to the acceleration direction, it is possible to sufficiently compensate for the decrease in the braking force of the braking by the brake pedal 25 accompanying the execution of the brake traction control.

Further, as shown in S33 to S35 of FIG. 5, the brake switch 59 is set to O for the predetermined times Δ and δ included in the ending condition of the engine traction control.
When the brake switch 59 is OF
When the brake switch 59 is ON, the end of the engine traction control is promoted so that the engine traction control is ended earlier when the brake pedal 25 is depressed to brake. can do.

Here, the correspondence relationship between each configuration of claim 1 and the configuration of the embodiment will be briefly described. The one corresponding to the engine traction control means is the traction control device 50, particularly the flowcharts of FIGS. Corresponding to the brake traction control means is the traction control device 50, particularly the flowcharts of FIGS. A brake switch 59 corresponds to the pedal operation detecting means. The one equivalent to the control amount of the brake traction control is the final target control amount FTbtg1 (i), FTb
It is tg2 (i). The target slip amount SBT for brake control corresponds to at least one physical amount used for setting the control amount. The equivalent of the condition changing means is the traction control device 50, particularly S in the flowchart of FIG.
24 to S26. What corresponds to the engine traction control end condition is S34 in the flowchart of FIG.
It is S35.

Next, various modifications of the above embodiment will be described. 1] In the table of Table 2, slip amount deviation EN and
The deviation change rate DEN is set as a parameter,
One of these may be set as a parameter. Further, instead of the table of Table 2, a table for engine traction control and a table for brake traction control may be separately provided. 2] The brake hydraulic pressure may be controlled by using the detection signals from the hydraulic pressure sensors 55 and 56 when the brake traction control is executed. 3] In the above-described embodiment, the traction control can be started even when the brake switch 59 is ON. When the brake switch 59 is ON, the traction control that has been executed until then is continued, but the traction control is newly added. It may be configured not to start.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a traction control device for a vehicle according to an embodiment.

FIG. 2 is a flowchart of a main routine of traction control.

FIG. 3 is a flowchart of a subroutine of slip amount detection processing.

FIG. 4 is a flowchart of a subroutine of target slip amount setting processing.

FIG. 5 is a flowchart of a subroutine of slip determination processing.

FIG. 6 is a flowchart of a subroutine of target control amount calculation processing for throttle control.

FIG. 7 is a flowchart of a subroutine of target control amount calculation processing for brake control.

FIG. 8 is a diagram showing a map M0.

FIG. 9 is a diagram showing a map M1.

FIG. 10 is a diagram showing a map M2.

FIG. 11 is a diagram showing a map M3.

FIG. 12 is a chart showing a map M4.

FIG. 13 is a diagram showing a map M5.

FIG. 14 is a time chart of wheel speed, throttle opening, brake hydraulic pressure, and the like.

[Explanation of symbols]

 1, 2 front wheels 3, 4 rear wheels 25 brake pedal 50 traction control device 51-54 wheel speed sensor 59 brake switch

Claims (3)

[Claims] 1. A brake traction control means for performing brake traction control on a braking means and an engine traction control means for performing engine traction control on an engine in order to suppress a slip of a drive wheel on a road surface. The vehicle traction control device is provided with a pedal operation detecting means for detecting the operation of the brake pedal, and the brake traction control means detects the operation of the brake pedal when the operation of the brake pedal is detected by the pedal operation detecting means. It is configured to continue the brake traction control that is being executed from before, and when the pedal operation detecting means detects the operation of the brake pedal, at least one physical quantity used for setting the control quantity of the brake traction control is applied to the braking promotion direction. Change to A traction control device for a vehicle, further comprising a condition changing means. 2. The vehicle traction control device according to claim 1, wherein the condition changing means is configured to change the target slip value as the physical quantity to a smaller value. 3. The end condition changing means for changing the engine traction control end condition toward the end promoting direction when the operation of the brake pedal is detected by the pedal operation detecting means. Alternatively, the vehicle traction control device according to claim 2.