JPH082294A - Vehicle traction control device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the engine speed from falling below a predetermined speed due to the shift-up together with the engine traction control. In a shift-up command process for shifting up a transmission together with engine traction control, a first-time flag Fi is set from 0 to 1 to start traction control, and a low-friction road is used to set the automatic transmission to the first speed. , When the engine speed is within a predetermined operating range of the first speed range of the shift map (S81 to S84: Yes), the engine speed Ne2u when upshifting to the second speed is estimated (S85), and the engine speed Ne2u is determined by the engine speed Ne2u. Only when the stall guard speed (1500 rpm) or higher (S86: Yes), the command signal for shifting up to the second speed is output, and then the predetermined time T
Holds in 2nd speed during 1st.

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 traction control device improved to prevent engine stall due to shift-up associated with engine traction control.

[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 traveling performance during vehicle acceleration, the slip amount of the driving wheels is detected and the slip amount of the driving wheels is detected. A traction control technique for a vehicle, which is configured to suppress the engine driving force so as to achieve a target slip amount, is generally put into 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, the slip amount of the drive wheel is calculated from the drive wheel speed and the driven wheel speed, and the driven wheel speed is calculated from the driven wheel speed. The target slip amount is set according to the determined vehicle speed and the road surface friction coefficient. The road surface friction coefficient is usually estimated from the driven wheel speed and its acceleration (Japanese Patent Laid-Open No. 60-99757).
(See the official gazette).

In order to suppress the slip of the driving wheels, a technique for suppressing the engine driving force is a retard of ignition timing and / or a fuel cut, or an adjustment of an intake amount through an auxiliary throttle valve in an intake passage, Etc. apply. For example,
JP-B-2-31779 discloses that when the slip amount of the driving wheels is equal to or larger than a predetermined value, the output torque of the engine is reduced through the fuel cut and the gear stage of the automatic transmission is shifted up to the highest gear stage. Technology is proposed.

Further, Japanese Patent Laid-Open No. 4-92729 discloses that
In the case of fuel cut by engine traction control, when the engine speed is above the predetermined speed and the fuel is cut, the automatic transmission is shifted up to reduce the engine speed and reduce the engine speed within the exhaust system catalyst. A vehicle driving force control device for suppressing combustion is described.

[0005]

When the automatic transmission is shifted up from, for example, the 1st gear to the 2nd gear together with engine traction control during or after starting the vehicle, the driving torque of the drive wheels is reduced, so that slippage occurs. Effective in suppressing. However, in this case, the engine speed is reduced by the gear ratio. However, when the shift-up is executed in a state where the engine speed is low such as at the time of starting or after starting, engine stall may occur due to the decrease in engine speed due to the shift-up, and the engine may stall. Even if the stall does not occur, there is a problem that the engine speed is excessively reduced and the controllability of the engine is degraded. An object of the present invention is to provide a traction control device for a vehicle that can be shifted up together with engine traction control and can prevent the engine speed from falling below a predetermined number of revolutions due to the upshift.

[0006]

According to a first aspect of the present invention, there is provided a traction control device for a vehicle comprising a traction control means for performing engine traction control for controlling a driving force of an engine for suppressing slip of a driving wheel on a road surface. In the traction control device, together with the wheel speed detection means for detecting the wheel speeds of the four wheels and the engine traction control by the traction control means, the transmission control means is instructed to shift up the automatic transmission to the next shift stage. Receiving the wheel speed of the drive wheel detected by the wheel speed detecting means, the engine speed when the upshift is performed by the shift up command means is estimated, and the engine speed is a predetermined speed. In case of less than, upshift is prohibited to upshift manual command means. Is that a shift-up inhibiting means.

A traction control device for a vehicle according to claim 2 is a traction control device for a vehicle, comprising traction control means for performing engine traction control for controlling a driving force of an engine in order to suppress slip of a driving wheel on a road surface. When the automatic transmission is in the first speed and is within the predetermined operating range of the shift map, the automatic transmission is set to the first speed by combining the wheel speed detection means for detecting the wheel speed of the wheels and the engine traction control by the traction control means. Engine speed in the case of receiving the wheel speeds of the drive wheels detected by the wheel speed detecting means and upshifting to the 2nd speed. If the engine speed is less than the predetermined speed, , In which a shift-up inhibition means for inhibiting a shift-up.

Here, the predetermined number of revolutions is an engine stall guard number of revolutions preset to prevent engine stall (claim 2 dependent on claim 1 or claim 2). The traction control means may be configured to control the driving force of the engine via combustion cut and / or ignition timing retard (claim 1 or claim 2).
Claim 3) dependent on. The traction control means may be configured to control the driving force of the engine so that the slip amount of the driving wheels reaches a target value (claim 4 according to claim 1 or claim 2).

[0009]

In the traction control device for a vehicle according to the first aspect of the present invention, the traction control means executes engine traction control for controlling the driving force of the engine in order to suppress the slip of the driving wheels on the road surface. The detection means detects the wheel speeds of the four wheels, and the upshift command means, together with the engine traction control,
The transmission control means is instructed to shift up the automatic transmission to the next shift stage, and the shift-up prohibiting means receives the detected wheel speed of the drive wheels and indicates the engine speed when the shift-up command means shifts up. If it is estimated that the engine speed is less than the predetermined speed, the shift-up manual command means prohibits shift-up.

As described above, the shift-up command means shifts up to the next shift stage together with the engine traction control to reduce the drive torque of the drive wheels, thereby promoting the suppression of the slip of the drive wheels. it can.
The shift-up prohibiting means can prevent the engine speed from becoming lower than a predetermined speed when the engine is upshifted. For example, in the case of shifting up from the 1st speed to the 2nd speed, if the engine stall guard speed set in advance to prevent the engine stall is applied as the predetermined speed, the engine speed will decrease and the engine speed will decrease. It is possible to reliably prevent the occurrence of stall, the excessive decrease in the engine speed, and the deterioration in the controllability of the engine.

According to another aspect of the vehicle traction control device of the present invention, the traction control means executes engine traction control for controlling the driving force of the engine in order to suppress the slip of the driving wheels on the road surface, and the wheel speed detecting means is 4 The wheel speed of the wheel is detected, and the up-shift command means, together with the engine traction control by the traction control means, when the automatic transmission is at the first speed and is within the predetermined operation range of the shift map, the automatic transmission is set at the first speed. The transmission control means is instructed to shift up from the second gear to the second gear.
The shift-up prohibiting means receives the detected wheel speed of the drive wheels,
When the engine speed is upshifted to the second speed in the predetermined operating range, the engine speed is estimated, and if the engine speed is less than the predetermined speed, the shift-up manual command means is prohibited from shifting up.

As described above, the shift-up command means shifts up from the first speed to the second speed together with the engine traction control to reduce the drive torque of the drive wheels, thereby promoting the suppression of the slip of the drive wheels. be able to. When the engine speed when shifting up to the 2nd speed is less than the predetermined speed by the shift-up prohibiting means, engine stall occurs or engine controllability deteriorates by prohibiting the shift-up. It is possible to surely prevent it from doing.

In the traction control device for a vehicle according to the third aspect of the present invention, the predetermined engine speed is the engine stall guard engine speed set in advance to prevent engine stall, so that the engine stall can be reliably prevented. In the traction control device for a vehicle according to claim 4, the traction control means controls the driving force of the engine via the combustion cut and / or the ignition timing retard. In this case, the configuration for the engine traction control is simple. It is advantageous in terms of manufacturing cost.

In the traction control device for a vehicle according to the present invention, the traction control means controls the driving force of the engine so that the slip amount of the drive wheels becomes a target value. In this case, the slip amount of the drive wheels is controlled. It can be reliably suppressed below the target value.

[0015]

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, and a V-type 6-cylinder engine 5 mounted on the front part of the vehicle body is used.
Drive torque from the automatic transmission 6 including the Tokuru converter and the planetary gear type transmission gear mechanism to the left and right rear wheels 3, 4 via the propeller shaft 7, the differential device 8 and the left and right rear wheel drive shafts 9, 10. It is configured to be transmitted.

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 throttle valve 16 which is interlocked with an accelerator pedal 15, and a distributor 17 which outputs ignition drive signals to the six ignition plugs in a predetermined order.

The left and right front wheels 1, 2 and the rear wheels 3, 4 receive disks 21a to 24a that rotate integrally with the wheels and brake hydraulic pressure, and these disks 21a to 24a.
Brake devices 21 to 24 each of which is composed of calipers 21b to 24b for braking the rotation of the brake device are provided, and a brake control system for operating these brake devices 21 to 24 is provided. The brake hydraulic system of each of the brake devices 21 to 24 has a general configuration as shown in the figure, and thus detailed description thereof will 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, a brake switch 59 which is turned on when the brake pedal 25 is operated, and an engine speed. A sensor 61, an accelerator sensor 62 for detecting the depression amount of the accelerator pedal 15, a throttle sensor 63 for detecting the opening degree of the throttle valve 16, and a mode switch 64 for setting a running mode (sport mode, normal mode, safety mode).
Etc., and a traction control unit 50 for performing engine traction control for the engine 5 and brake traction control for the brake devices 23, 24 of the left and right rear wheels 3, 4 are provided.
In addition, an engine control unit 50 that controls the engine 5
And a transmission control unit 70 for controlling the automatic transmission 6.

Each of the wheel speed sensors 51 to 54 has a structure in which a plurality of detecting portions formed on the brake discs 21a to 24a or the discs in the vicinity thereof are detected by an electromagnetic pickup. Detection signals from the sensors and switches are supplied to the traction control unit 50, and a signal indicating the shift speed of the automatic transmission 6 is supplied from the transmission control unit 70. From the traction control unit 50 to the engine control unit 60
Is supplied with a control signal for engine traction control, and the electromagnetic opening / closing valves 31, 46, 36, 37, 39, 4 are supplied.
A control signal for brake traction control is supplied to 0.

Further, the traction control unit 50 outputs, to the transmission control unit 70, a command signal for instructing switching of the shift speed by traction control.
The engine control unit 60 executes fuel cut and ignition timing retard based on a control signal for traction control. The transmission control unit 70 executes the shift control for the automatic transmission 6 based on the vehicle speed V, the detection signal of the throttle opening of the throttle valve 16, the signal indicating the operation position of the shift lever, and the shift map. However, since it is similar to a general transmission control device, detailed description thereof will be omitted.

The brake control will be briefly described below.
When the electromagnetic opening / closing valve 31 is opened and the electromagnetic opening / closing valve 46 is closed when the brake traction control is not executed, the brake hydraulic pressure is applied from the booster 26 to the braking device 21 during braking.
~ 24. At the time of brake traction control, the electromagnetic opening / closing valve 31 is closed and the electromagnetic opening / closing valve 46 is opened.
By appropriately controlling the duty of the electromagnetic on-off valves 36, 37, 39, 40, the braking devices 23, 2 for the left and right rear wheels 3, 4 are controlled.
The brake hydraulic pressure of No. 4 can be controlled to a desired pressure. The brake traction control is the same as the general brake traction control, and thus detailed description thereof will be omitted.

The traction control unit 50 includes a waveform shaping circuit for shaping the detection signals from the sensors and switches as necessary, and the detection signals as required by A.
A / D converter for D conversion, input / output interface,
Microcomputer, electromagnetic on-off valves 31, 46, 36,
37, 39, 40, etc., and a plurality of timers, etc., and a microcomputer ROM stores in advance control programs for engine traction control, tables, maps, etc. Work memory is provided.

Next, the traction control unit 50
2 for the engine traction control executed in
The following description will be made with reference to the drawings, but first, an outline of the engine traction control (slip control) will be described. The target slip amounts of the drive wheels 3 and 4 are set according to the running state of the vehicle and the road friction state, and the drive wheels 3 and 4 are set.
Is calculated by using the wheel speeds of the four wheels, and the fuel cut and / or the ignition timing retard is adjusted so that the slip amount becomes equal to or less than the target slip amount for engine control when the vehicle starts or accelerates. Take control.

In particular, this engine traction control is
When starting the traction control on a low friction road surface or when starting traction control during running, the engine speed when the gear position of the automatic transmission 6 is upshifted from the first speed to the second speed and upshifted to the second speed is the engine stall guard speed. (1500 rp
When it is less than m), upshift to second gear is prohibited (see FIG. 20). Next, the engine traction control will be described with reference to the drawings starting from FIG. The flowchart of FIG. 2 is a flowchart of a main routine of engine traction control, and this routine is executed every predetermined minute time (for example, 8 ms). Incidentally, the reference symbol Si (i = 1, 2, 3, ...) In the flowchart indicates each step.

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 an engine control target control amount calculation process is executed (S).
4) Next, under the condition that the engine control slip flag Fe = 1, an engine control control signal is output to the engine control unit 60 (S5), and then the process returns.

Next, each subroutine of S1 to S4 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 engine control slip amount Se is calculated as (Vm-V) as shown, and the data of the slip amount Se is stored in the work memory while being updated.

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 (accelerator opening degree), the detected steering angle θ, the mode signal from the mode switch 64, and the like) 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 surface friction coefficient μ, 100 m
Using a timer for counting s and a timer for counting 500 ms, 1 is set every 100 ms from the start of slip control until 500 ms when the vehicle body acceleration Vg does not become sufficiently large.
The vehicle body acceleration Vg is calculated from the change of the vehicle speed V during 00 ms by the following equation (1), and after 500 ms when the vehicle body acceleration Vg becomes sufficiently large, 500 m is calculated every 100 ms.
From the change of the vehicle speed V during s, the vehicle body acceleration Vg is calculated by the following equation (2). Note that V (i) is currently V (i-10
0) is 100 ms before, V (i-500) is 500 ms before, and K1 and K2 are predetermined constants.
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.

[0030]

[Table 1]

Next, in S21, the map M0 shown in FIG.
The road surface friction coefficient μ is applied to the engine control target slip amount basic value SETo. Next, the basic value S
Coefficient k for correcting ETo according to the running condition of the vehicle
1 to k4 are calculated in S22. In this S22, the vehicle speed V is applied to the map M1 of FIG. 7 to calculate the coefficient k1, the accelerator depression amount is applied to the map M2 of FIG. 8 to calculate the coefficient k2, and the steering angle θ is added to the map M3 of FIG. Is applied to calculate the coefficient k3, and the coefficient k4 is calculated from the map M4 of FIG. 10 and the mode signal. Next, in S23, the coefficient KD obtained by multiplying the coefficients k1 to k4 is calculated, and then, in S24, the engine control target slip amount S.
ET is calculated as SET = basic value SETo × KD and stored in the work memory.

Slip determination process ... See FIG. 5. The slip determination process is a slip determination, that is, a slip flag Fe for identifying the necessity of traction control,
This is a process for setting the initial flag Fi, and when this process is started, various signals (slip amount Se, target slip amount SET, previous slip flag Fe (k-1), flag Fi, flag Ft, Etc.) is read (S3
0) Next, it is determined whether the slip amount Se is larger than the target slip amount SET (S31). If the determination is No, the process proceeds to S35, and if the determination is Yes,
The slip flag Fe is set to 1 (S32), and next, whether or not the previous slip flag Fe (k-1) is 0, that is,
It is determined whether or not a new series of traction control will be entered this time (S33). If the determination in S33 is Yes, the initial flag Fi is set to 1 (S34) (see FIG. 22), and then the process proceeds to S4.

If the determination in S31 is No, it is determined whether or not the initial flag Fi is 1 (S35), and when the initial flag Fi is 1, the flag Fi is reset to 0 (S3).
6) Next, when the timer flag Ft is not set to 1 (S37: No), for example, a count-up type timer T (counting its time count) from 0 to 3000 ms is started after reset. (S3
8) Next, after setting the flag Ft (S39), the process proceeds to S4.

On the other hand, when the flag Ft is 1 (S37: Ye
s), it is determined whether the time T counted by the timer T is a predetermined value T0 (for example, T0 = 2000 ms) or more (S40). If the determination is No, the process proceeds to S4, but the determination is Yes.
, That is, slip amount Se ≦ target slip amount SE
When the state of T, continues for the predetermined time T0, the slip flag Fe is reset to 0 (S41), the flag Ft is reset to 0 (S42), and then the process proceeds to S4. As described above, the setting of the flags Fe and Fi is executed.

Target control amount calculation process for engine control ...
See FIG. 11 and FIG. 12. This calculation process is performed by the engine traction control (
(It may be abbreviated as TCS.) This is a process executed during execution, that is, when the slip flag Fe = 1,
When this calculation process is started, various signals (slip amount S
e, accelerator opening Aco, engine speed Ne, low slip identification flag F, vehicle speed V, road friction coefficient μ, previous control level FC (k -1), previous target TVO (k -1), maximum drive wheel The data such as the speed Vm) is read (S50). However, the subscript (k-1) indicates the previous value, the subscript (k) indicates the current value, and "TVO" indicates the throttle opening.

Next, in S51, it is determined whether or not the low-slip identification flag F is 0. Since this flag F is set to 0 in the initial setting, it is initially S51 to S61.
Then, it is judged whether the measured time TM of the timer TM is 1.0 second or less. If the timer TM is not started in S57, the determination in S61 is No, so the process proceeds from S61 to S52. In S52, it is determined whether or not the flag F is 1, but initially it is determined to be No and the process proceeds to S53. Next, in S53, it is determined whether or not the drive wheel speed is close to the driven wheel speed, the slip amount Se of the drive wheels 3 and 4 is small, and the change rate of the drive wheel speed is small. Vm ≦ (V + 2.0 Km / H) and ΔDVm ≦ 0.
3 Judge whether or not. Note that ΔDVm is the maximum drive wheel speed Vm
Is the absolute value of acceleration / deceleration of.

When the running road surface changes to a high friction road surface, the determination in S53 is Yes, but even if the running road surface is a low friction road surface, excessive braking is performed, or When the engine driving force is excessively suppressed by the engine traction control, the determination in S53 is Yes. When the determination in S53 is Yes, S54
Then, the flag F is set to 1, and the process proceeds to S59.
When the determination in S53 is No, S54 is skipped and the process proceeds to S59. S59 and S60 are steps for setting a target TVO in normal engine traction control, and in S59, the following Table 2 to Table 4 are set.
From this, the change amount of the target TVO is calculated.

[0038]

[Table 2]

[0039]

[Table 3]

[Table 4]

In the table of Table 2, ZO is the target TV
O indicates holding, N is reduction of target TVO, P is target TV
O indicates an increase, and the subscripts S, M, B indicate the target TVO.
Shows the magnitude of the change amount of S, S is "small change amount", M
Indicates "medium change" and B indicates "large change". The table of Table 3 is a numerical representation of the symbol of the amount of change in the table of Table 2, and its unit is% of the TVO unit.
The table of Table 2 shows that the slip amount Se and the target slip amount S
The slip amount deviation EN, which is the deviation of ET, and its deviation change rate DEN are set as parameters, and this slip amount deviation EN (k) = (Se-SET) is calculated, and this deviation change rate DEN ( k) = current deviation EN (k) -previous deviation EN (k-1), and this time slip amount deviation EN (k) and current deviation change rate DEN (k) are calculated, and these are calculated. By applying to the table of Table 2, the change amount ΔTVO of the target TVO is calculated, and the change amount ΔTVO is shown in Table 3.
The change amount ΔTVO of the target TVO is digitized by applying the above.

Then, in order to correct the change amount ΔTVO of the target TVO according to the operating state of the engine, the detected engine speed Ne and the detected TVO are applied to the table of Table 4, and the correction coefficient Ke is calculated. Then, the final change amount ΔTVO of the target TVO is calculated as ΔTVO = ΔTVO × Ke. Next, in S60, this target TVO
However, by adding the change amount ΔTVO to the previous target TVO (k-1), target TVO = previous target TVO (k-1) + ΔT
It is calculated as VO, and then the process proceeds to S64.

Next, in S64, the detected engine speed Ne and the target TVO of this time are shown in the map M6 of FIG.
By applying the target engine torque Tmtcs during execution of TCS
Is calculated. Next, in S65, the detected engine speed Ne and the detected accelerator opening Aco are applied to the map M7 of FIG. 15 to obtain the engine torque Tnt when TCS is not executed.
cs is calculated. It should be noted that the map M6 is set to a characteristic in which the engine driving force is significantly suppressed as compared with the map M7.

Next, in S66, the engine torque output ratio ETR is calculated as ETR = 100 × Tmtcs / Tntcs. Next, in S67, it is determined whether or not the flag F is 1, but the flag F is 0. Sometimes, the process proceeds to S69, and when the flag F is 1, the slip amount Se of the driving forces 3 and 4 is small. Therefore, in order to correct the increase of the engine driving force, the engine torque output ratio ETR is set to a predetermined value in S68. After being significantly changed (for example, 5%), S
Go to 69.

Next, in S69, the map M of FIG.
The control level FC of this time is calculated by applying the engine torque output ratio ETR to 8. Next, in S70, the control level FC of this time is set to the map M9 of FIG.
Map M1 in which the maximum value of the ignition retard amount in FIG. 18 is set
0 and the ignition retard amount is calculated, and then S
At 71, the control level FC of this time is applied to the map M11 in which the fuel cut prohibition region of FIG. 19 is set and the fuel cut table of Table 5, the fuel cut pattern is calculated, and then the process proceeds to S5 of FIG. To do. In addition, the following Table 5
The fuel cut pattern number in the control level FC
Is equivalent to

[0045]

[Table 5]

As described above, when the slip amount Se of the drive wheels 3 and 4 is large and the determination in S53 is No, the normal engine traction control via S59 and S60 is executed, but the actual running road surface is The slip amount Se of the drive wheels 3 and 4 is reduced by changing to a high friction road surface, or the slip amount Se of the drive wheels 3 and 4 is still low friction road surface.
Becomes smaller or the low slip identification flag F is set to 1, the process proceeds to S55 through S51 and S52, and at S55, the maximum drive wheel speed Vm is Vm> (V
+3.0 Km / H), that is, whether or not the slip amount Se of the drive wheels 3, 4 has started to increase. If the determination is Yes, the flag F is reset to 0 (S56), In addition, a count-up timer TM that counts from 0 to 5.0 seconds (whose time is TM) is started after reset (S57), the process proceeds from S57 to S59, and S59 and subsequent steps are executed in the same manner as described above. To be done.

When the road surface actually shifts to a high friction road surface,
The slip amount Se of the drive wheels 3 and 4 does not show an increasing tendency, and S
Although the determination of 55 is No, in this case, the process proceeds from S55 to S58, and it is determined whether or not the previous control level FC (k-1) is 0. And at the beginning, the decision is N
Since it is o, the process proceeds from S58 to S59, and the steps from S59 onward are executed in the same manner as described above, and the control level FC gradually decreases. As a result, when the control state FC (k-1) becomes 0 after the fuel cut state is completely restored and the previous control level FC (k-1) becomes 0, the determination in S58 becomes Yes. Therefore, the process proceeds from S58 to S56 and S56. The subsequent steps are executed in the same manner as described above.

After the flag F is reset to 0 in S56, the process proceeds from S51 to S61. In S61, it is determined whether the time TM of the timer TM is 1.0 seconds or less. Shifts to S62 and S6
At 2, it is determined whether the slip amount Se of the drive wheels 3 and 4 is equal to or greater than a set value Co (for example, 20 Km / H). If the road surface is actually a high-friction road surface, the determination is No, so the process proceeds from S62 to S59, and S59 and the subsequent steps are executed in the same manner as described above.

On the other hand, when the road surface is still a low friction road surface but is erroneously controlled as a high friction road surface, the engine driving force is increased before the flag F is set to 1. Therefore, after resetting flag F to 0, 1.
The slip amount Se of the drive wheels 3 and 4 rapidly increases within 0 second, and therefore the determination in S62 becomes Yes. in this case,
In S63, the vehicle speed V and the road surface friction coefficient μ are applied to the map M5 of FIG. 13 in order to rapidly reduce the engine driving force and suppress the torque in S63.
Target T that is significantly smaller than the values set in 59 and S60
VO is calculated, and then the process proceeds to S64.

As described above, when the target TVO is set small, the target engine torque Tmtcs at the time of executing the TCS becomes significantly small, the engine torque output ratio ETR is set small, and as a result, the control level FC is set large. Control is performed so that the engine driving force is sharply reduced. While the flag F is 0 and the target TVO is set from the repetitive map M5 while TM ≦ 1.0 seconds, the repetitive control level FC is set to a large value, the engine driving force is rapidly reduced, and the slip of the drive wheels 3 and 4 is reduced. Will be suppressed.
It should be noted that the target T is changed from the map M5 only once within TM ≦ 1.0 seconds.
It may be configured to set the VO.

Next, the shift-up command processing for the automatic transmission 6 for reducing the torque of the drive wheels at the start of the traction control will be described with reference to the flowchart of FIG. It is included in the control, and in parallel with the main routine of FIG. 2, a predetermined minute time (for example, 8 ms)
It is executed every other time. However, this shift-up command processing may be executed in the main routine of FIG. First, various signals (for example, the previous flag Fi (k
-1), current flag Fi (k), road friction coefficient μ, vehicle speed V, detected throttle opening, target slip amount SE of driving wheel SE
T, the detected wheel speeds of the four wheels, data such as a signal indicating the current gear position supplied from the transmission control unit 70) are read (S80).

Next, it is determined whether or not the previous flag Fi (k-1) = 0 and the current flag Fi (k) = 1, that is, whether or not the traction control is newly entered this time (S81). ,
When the determination is Yes, it is determined whether or not the road surface is a low friction road surface (S82), when the determination is Yes, it is determined whether or not the current gear is the first speed (S83), and when the determination is Yes. , The vehicle speed V and the throttle opening are stored in the traction control unit 50 in the map M1 of FIG.
2 is applied to determine whether the driving state determined by the vehicle speed V and the throttle opening is within the area Z of the map M12 (S8).
4) If the determination is Yes, the process proceeds to S85.
If any of S82 to S84 is No,
To return.

Note that the map M12 in FIG. 21 is sufficient if the area Z is set, but is shown including the shift map stored in the transmission control unit 70 to facilitate understanding. , “N” (n = 1, 2, 3, 4) in the figure indicates a shift speed.

Next, in S85, the engine speed N when the shift stage of the automatic transmission 6 is shifted up to the second speed.
e2u is calculated as follows. Assuming that the gear ratio of the second gear is 2.78, the gear ratio of the differential device 8 is 4.1, and the length of one round of the rear wheels 3 and 4 is 2 m, the average wheel speed Vd of the rear wheels 3 and 4 is Vd.
The relationship between (Km / H) and engine speed Ne (rpm) is
Vd = 0.0105 × Ne, but the average wheel speed Vd = (V3
Since it is + V4) / 2, the engine speed Ne2u when shifting up to the second speed in the current running state is 0.
From the relational expression of 105 × Ne2u = (V3 + V4) / 2, Ne2
u = (V3 + V4) / (2 × 0.0105). However, the drive wheel speed is at least (driven wheel speed + target slip amount S
Since the average wheel speed Vd may be reduced to (ET), (the vehicle speed V + the target slip amount SET) is used as the average wheel speed Vd, and the engine speed Ne2 when shifting up to the second speed is performed.
You may ask u.

In S86 following S85, it is determined whether the engine speed Ne2u is 1500 rpm or more preset as the engine stall guard speed. If the result of the determination is Yes, the transmission 6 is set to 2 in S87. A command signal for shifting up to the first speed is output to the transmission control unit 70 to shift up the transmission 6 to the second speed, and then the process returns. That is, when the traction control execution state is entered while traveling on the low friction road surface at the first speed, the drive wheels 3,
In order to suppress the slip by suppressing the driving torque of No. 4 and forcibly shifting up to the second speed, in S88, for example, a count-up type timer Tm that counts up to 1000 ms (Tm) is started after reset and then returns.

However, the determination in S86 is No, and the engine speed Ne2u when shifting up to the second speed is 1500 rp.
When it is less than m, the engine speed Ne may decrease to a value smaller than 1500 rpm due to the shift-up to the 2nd speed, and engine stall may occur. To prevent this, shift up to the 2nd speed. In order to prohibit, S87 is skipped and the process directly returns.

If the determination in S81 is No, the flag F
It is determined whether i (k) is 1 (S89), and if the determination is Yes, it is determined whether the time Tm of the timer Tm is less than or equal to a predetermined value T1 (for example, 500 ms), and the determination is Yes. In this case, in S91, the vehicle speed V and the detected throttle opening degree are applied to the map M12, and it is determined whether or not the current driving state is within the area Z of the map M12 (S9).
1) If the result of the determination is Yes, a command signal for holding the shift speed at the second speed is output to the transmission control unit 70 (S9).
2) Then return. Therefore, even after the execution of the traction control, as long as it is in the area Z, the shift speed is maintained at the second speed.

However, since the shift map is as shown in FIG. 21, even if the operating state is in the area Z, the shift from the 2nd speed to the 1st speed is performed.
As long as the shift down line to high speed is not exceeded to the low vehicle speed side,
Since the second speed is maintained, depending on the configuration of the shift control control program in the transmission control unit 70, S8
It is also possible to omit steps 8 and S89 to S92.

The operation of the engine traction control described above will be described. As shown in FIG. 22, when the engine driving force increases during acceleration, the slip amount Se of the driving wheels 3 and 4 increases above the target slip amount SET while traveling on a low friction road surface, and the engine traction control is performed. Is started at time t0, the engine traction control is executed, the flag Fi is held at 1 in the first slip occurrence state, and the flag Fe is held at 1 during a series of traction control execution. At the start of the execution of this traction control, although the description is omitted in the above description, the control level FC is actually +
The engine driving force is sharply reduced because it is increased and corrected by about 3 to 5, and then the target TV obtained in S59 and S60.
The normal engine traction control using O is continuously executed, the engine driving force is reduced through the fuel cut and the ignition timing retard, and the slip of the driving forces 3 and 4 is reduced.

When the slip amount Se converges and approaches the target slip amount SET or less, the engine driving force is gradually increased after time t1, and the slip amount Se is equal to or less than the target slip amount SET for a predetermined time (S40). The engine traction control is continued while the predetermined time T0 described in (2) is not continued for 2.0 seconds. In the vicinity of time t2, when the running road surface actually shifts from the low-friction road surface to the high-friction road surface, the engine driving force is reduced, and the slip amount Se is in a low slip state. Although the slip amount Se increases a little as shown by the chain line B in response to the subsequent return of the engine driving force, the state of the target slip amount SET or less is continued, and the engine traction control ends when the state continues for a predetermined time.

By the way, even if the road surface on which the vehicle is traveling is still a low-friction road surface, a low slip state may occur due to an extreme decrease in engine driving force, a brake operation, or the like. In this case, as in the case of the high friction road surface, when the engine driving force is restored, the slip amount Se may suddenly increase and spin may occur as shown by the dotted line C because of the low friction road surface.

Therefore, at time t3, the slip amount Se
When the tendency to increase is generated, the flag F is reset to stop the driving force increase correction of S68, and if the slip amount Se increases to the set value Co or more within 1.0 seconds after resetting the flag F, By determining that the low friction road surface is still continuing and setting the target TVO from the map M5 in order to prevent the sudden increase in slip, the engine driving force is rapidly reduced at time t4, and then from time t3. As long as the slip amount Se is equal to or larger than the set value Co for 1.0 second, the target TVO is set from the map M5, the engine driving force is kept small, and then the normal engine traction control is performed. As a result, as shown by the solid line A, it is possible to reliably prevent the slip amount Se from rapidly increasing.

By the way, this traction control is performed as shown in FIG.
This is characterized by a shift-up command processing of 0. By this processing, a traction control execution state is entered while traveling on a low-friction road surface at the first speed, and an operating state in which the vehicle speed V and the throttle opening are used as parameters. If the engine Z is in the region Z of the map M12 and the engine speed Ne is not reduced below the engine stall guard speed (1500 rpm) even if shifting up to the second speed, the engine speed Ne is forced to 2 By shifting up to high speed, the drive torque transmitted to the drive wheels 3 and 4 can be reduced, slip can be suppressed, and slip convergence can be promoted.

Incidentally, when the current flag Fi (k) = 1 and within the area Z of the map M12, the shift speed is held at the second speed, so that the slip suppressing action can be maintained. Particularly, in the second speed, the change width of the drive torque due to the traction control is smaller than that in the first speed, so that the traction control can be smoothly performed.

Even if the operating condition is within the area Z of the map M12, the engine speed Ne becomes the engine stall guard speed (15
If it is less than 00 rpm), upshift to 2nd speed is prohibited, so engine stall may occur due to the decrease in engine speed due to upshift, or even if engine stall does not occur, engine speed may decrease. It is possible to reliably prevent the controllability of the engine from decreasing. Furthermore, because the speed does not forcibly shift up to the 3rd or 4th high speed stage, due to the sudden increase in the wheel speeds of the drive wheels 3 and 4,
The slip amount of the drive wheels 3 and 4 does not transiently increase and the slip suppressing action is not impaired. In addition, since the upshift to the second speed is not performed during traveling on the high friction road surface, the acceleration performance on the high friction road surface does not deteriorate.

Next, a description will be given of a modified mode in which a part of the above embodiment is modified. 1] Numerical values in FIG. 11 and FIG. 12, “1.
0sec "," 2.0Km / H "in S53 and" 0.3G ", S
“3.0 Km / H 2” and the like in 55 are merely examples, and may be changed to different values. Also, map M5
The map M12 also shows only an example and is not limited to these. Further, the engine stall guard rotation speed (1500 rpm) in FIG. 20 is merely an example, and the present invention is not limited to this.

2] When the low range hold mode or the low range is set for the automatic transmission, the automatic transmission may be configured to hold the first speed regardless of the command signal in S87 of FIG. desirable.

3] The transmission control unit 70 has a normal shift map (for example, a shift map excluding the line L12 in FIG. 21) and a shift map for shift-up command processing. A shift-up command processing shift map for shifting up from the first speed to the second speed is stored, and in S87 of FIG. 20, the shift-up command processing shift map is stored for a predetermined time (for example, 500 ms). It may be configured to output a command signal for gear shift control based on the above.

4] Instead of the shift ship command processing of FIG. 20, the shift ship command processing of FIG. 23 may be applied. In FIG. 23, steps S100 to S102 are the same as steps S80 to S82, and therefore description thereof will be omitted. In S103, the engine speed Neu when the current gear n-th speed is upshifted to the (n + 1) th speed is the same as that of the above embodiment using the average wheel speed Vd of the driving wheels and the gear ratio of the (n + 1) th speed. Then, in S104, it is determined whether or not the engine speed Neu at the time of shifting up to the (n + 1) speed is 1500 rpm (engine stall guard speed) or more, and the determination is made.
When Yes, the gear shift stage may be configured to output to the transmission control unit 70 a command signal that shifts up to the (n + 1) th speed and continues for a predetermined time (for example, 500 ms).

As described above, when the traction control is started, by shifting up to the next gear, it is possible to reduce the driving torque of the driving wheels and promote the slip suppression of the driving wheels. Similarly to the above-described embodiment, it is possible to reliably prevent the engine stall from occurring due to the decrease in the engine speed due to the shift-up and the deterioration of the controllability of the engine due to the decrease in the engine speed.

5] The main routine of the engine traction control of FIG. 2 in the above embodiment is merely an example, and various existing engine traction controls may be applied instead. For example, engine traction control performed only through fuel cut, traction control performed through fuel injection amount control, engine traction control performed through ignition timing retard, and engine traction control that controls intake air amount through a sub-throttle. Similarly, the present invention can be similarly applied, and in the diesel engine, the present invention can also be applied to those that perform traction control via the fuel injection amount amount or the fuel injection amount timing. For traction control when driving with an electric motor instead of the engine,
The present invention can be applied. Further, it goes without saying that various modifications can be added to a part of the embodiment without departing from the spirit of the present invention.

[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 engine 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 diagram showing a map M0 in which a basic value of basic slip amount is set.

FIG. 7 is a diagram showing a map M1 in which a coefficient k1 is set.

FIG. 8 is a diagram showing a map M2 in which a coefficient k2 is set.

FIG. 9 is a diagram showing a map M3 in which a coefficient k3 is set.

FIG. 10 is a chart showing a map M4 in which a coefficient k4 is set.

FIG. 11 is a part of a flowchart of a subroutine of target control amount calculation processing for engine control.

FIG. 12 is a flowchart following FIG. 11.

FIG. 13 is a diagram showing a map M5 in which a target TVO is set.

FIG. 14 is a diagram showing a map M6 in which a target engine torque at the time of executing TCS is set.

FIG. 15 is a diagram showing a map M7 in which engine torque is set when TCS is not executed.

FIG. 16 is a diagram showing a map M8 in which a control level FC is set.

FIG. 17 is a diagram showing a map M9 in which an ignition retard amount is set.

FIG. 18 is a map M in which the maximum value of the ignition retard amount is set.
It is a diagram showing 10.

FIG. 19 is a map M11 in which a fuel cut prohibited area is set.
FIG.

FIG. 20 is a flowchart of shift-up command processing.

FIG. 21 is a diagram showing a map M12.

FIG. 22 is a time chart of wheel speed, engine driving force, flags and the like.

FIG. 23 is a flowchart of shift-up processing according to a modification.

[Explanation of symbols]

 1, 2 front wheels (driven wheels) 3, 4 rear wheels (driving wheels) 5 engine 6 automatic transmission 14 injector 17 distributor 50 traction control unit 60 engine control unit 70 transmission control unit 51-54 wheel speed sensor 58 steering angle sensor 61 engine speed sensor 62 accelerator sensor 63 throttle opening sensor 64 mode switch

Front page continued (72) Inventor Tomoyuki Hirao 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Motor Corporation

Claims (5)

[Claims] 1. A traction control device for a vehicle, comprising a traction control means for performing engine traction control for controlling an engine driving force for suppressing slip of a drive wheel on a road surface, a wheel speed for detecting wheel speeds of four wheels. A detection means, an engine traction control by the traction control means, a shift-up command means for instructing the transmission control means to shift up the automatic transmission to the next gear, and the wheel speed detection means. Receiving the wheel speed of the drive wheels, the engine speed in the case of upshifting is estimated by the upshift command means, and if the engine speed is less than the predetermined speed, to the upshift manual command means, A vehicle up-shifting means for inhibiting up-shifting; Deployment control apparatus. 2. A traction control device for a vehicle, comprising a traction control means for performing engine traction control for controlling a driving force of an engine for suppressing slip of driving wheels on a road surface, a wheel speed for detecting wheel speeds of four wheels. In combination with the detection means and the engine traction control by the traction control means, the automatic transmission is shifted up from the first speed to the second speed when the automatic transmission is in the first speed and is in the predetermined operation range of the shift map. In response to the shift-up command means for instructing the transmission control means and the wheel speed of the driving wheels detected by the wheel speed detection means, the engine speed in the case of up-shifting to the second speed is estimated, and the engine speed is estimated. If the number of rotations is less than the predetermined number of rotations, the shift-up manual command means prohibits shift-up A traction control device for a vehicle, comprising: stop means. 3. The vehicle traction control device according to claim 1, wherein the predetermined rotation speed is an engine stall guard rotation speed that is preset to prevent engine stall. 4. The traction control means is configured to control the driving force of the engine via combustion cut and / or ignition timing retard. Vehicle traction control device. 5. The traction control means is configured to control the driving force of the engine so that the slip amount of the driving wheels reaches a target value. Vehicle traction control device.