JP3438305B2 - Vehicle traction control device - Google Patents

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 performing engine traction control and brake traction control of a vehicle, and more particularly, to a set vehicle speed for prohibiting operation of brake traction control, a road surface friction coefficient,
About that be changed according to the split road surface.

[0002]

2. Description of the Related Art Conventionally, during acceleration of a vehicle, in order to prevent the driving wheels from slipping due to excessive driving torque and deteriorating the running performance, a slip ratio or slip amount of the driving wheels (this is called a slip value). Traction of the vehicle configured to detect the engine speed and control the engine driving force and the braking force applied to the wheels (reduce the engine driving force or increase the braking force) so that the slip value of the driving wheel becomes the target slip value. Control technology is generally in 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 speed and the road surface friction coefficient (which is abbreviated as μ). The road surface friction coefficient is estimated from the driven wheel speed and its acceleration (see Japanese Patent Laid-Open No. 60-99757). In order to suppress the slip of the driving wheels, a technique for suppressing the engine driving force is retard of ignition timing and / or
Alternatively, fuel cut or adjustment of the intake air amount via the auxiliary throttle valve in the intake passage is applied.

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).

Further, in Japanese Unexamined Patent Publication No. 2-262455, when the brake traction control is operated during high speed traveling, vehicle body vibration is likely to occur and the traveling state is easily destabilized, and the brake mechanism is overloaded. Considering that the fade phenomenon is likely to occur, for example, a traction control technique has been proposed which is configured to prohibit the brake traction control when traveling at a high speed of 125 Km / h or more. However, the set vehicle speed is not limited to an example, and in the normal case, the set vehicle speed is often set to about 60 km / h.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the traction control disclosed in Japanese Patent No. 455, the operation of the brake traction control is prohibited when the vehicle is traveling at a high speed equal to or higher than the set vehicle speed. However, fixing the set vehicle speed that prohibits the brake traction control to a constant value is not preferable in various respects .

When the set vehicle speed for low μ road traveling is set higher than the set vehicle speed for high μ road traveling, the engine is controlled by engine traction control while the brake traction control is prohibited during high μ road traveling. The driving force may be reduced too much, resulting in stall. Further, when traveling on a low μ road, the brake mechanism is overloaded and the fade phenomenon is likely to occur due to frequent brake traction control.
As described above, in order to ensure acceleration and durability of the brake mechanism, it is desirable to set the set vehicle speed when traveling on a low μ road to be lower than the set vehicle speed when traveling on a high μ road.

An object of the present invention is to provide a traction control device for a vehicle capable of changing a set vehicle speed for inhibiting brake traction control according to a road surface friction coefficient, and a vehicle traction capable of changing the set vehicle speed depending on whether or not a split road surface is present. it is to provide a control equipment.

[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. In a traction control device for a vehicle including an engine traction control means for performing engine traction control, a vehicle speed detection means for detecting a vehicle speed and an engine traction control when the vehicle speed detected by the vehicle speed detection means is less than a set vehicle speed. Means and the brake traction control means operation, when the vehicle speed is equal to or higher than the set vehicle speed, the traction regulation means for prohibiting the operation of the brake traction control means, the road surface friction detection means for detecting the road surface friction coefficient, and the set vehicle speed, Detected by road friction detection means And a set vehicle speed changing means for changing in accordance with the road surface friction coefficient, the speed setting change means a high friction
Set the vehicle speed on a rubbing road surface to the setting vehicle speed on a low friction road surface.
It is configured to be set higher than speed .

[0010]

According to a second aspect of the present invention, there is provided a traction control device for a vehicle, which comprises a brake traction control means for performing brake traction control on a braking means and an engine traction control for an engine in order to suppress slippage of driving wheels on a road surface. In a traction control device for a vehicle including an engine traction control means for performing, a vehicle speed detection means for detecting a vehicle speed, and an engine traction control means and a brake traction control means when the vehicle speed detected by the vehicle speed detection means is less than a set vehicle speed. When the vehicle speed is equal to or higher than the set vehicle speed, traction regulation means for prohibiting the operation of the brake traction control means, split road surface determination means for determining whether or not the road surface is a split road surface, and the set vehicle speed for the split road surface determination means At It has been a set vehicle speed changing means for changing in accordance with whether a split road surface, the set vehicle speed variable
The way to change is to set the vehicle speed when split road surface
Set higher than the set vehicle speed when not on a road
It is composed of.

[0012]

[0013]

[0014]

In the traction control device for a vehicle according to the present invention, the vehicle speed detecting means detects the vehicle speed in the traction control including the engine traction control and the brake traction control for suppressing the slip of the driving wheels on the road surface. However, the traction restricting means permits the operation of the engine traction control means and the brake traction control means when the vehicle speed detected by the vehicle speed detecting means is lower than the set vehicle speed, and the operation of the brake traction control means when the vehicle speed is equal to or higher than the set vehicle speed. Ban. When the road friction coefficient is detected by the road friction detecting means, the set vehicle speed changing means changes the set vehicle speed according to the road friction coefficient detected by the road friction detecting means.

Therefore, by prohibiting the brake traction control when the vehicle speed is higher than the set vehicle speed, it is possible to prevent the occurrence of vehicle vibration and the fade phenomenon of the brake mechanism which are caused by the brake traction control when the vehicle speed is higher than the set vehicle speed. In addition, by changing the set vehicle speed according to the road surface friction coefficient, in view of slip suppression and traveling stability assurance, acceleration performance, durability of the brake mechanism, etc.,
The set vehicle speed can be changed according to the road surface friction coefficient.

Then, the set vehicle speed on a high friction road surface is
Since set higher than the set vehicle speed when the low-friction road surface,
Since the range of application of the brake traction control can be widened when traveling on a high friction road surface, it is possible to prevent the engine traction control from reducing the driving force of the engine too much to reduce the acceleration performance.Also, when traveling on a low friction road surface, the brake mechanism is overloaded. This can prevent the fade phenomenon from occurring.

[0017]

[0018]

[0019] In the traction control apparatus according to claim 2 vehicle, the traction control including an engine traction control and brake traction control for suppressing a slip relative to the road surface of the driving wheels, vehicle speed detection means detects a vehicle speed, traction When the vehicle speed detected by the vehicle speed detection means is less than the set vehicle speed, the regulation means
The operation of the engine traction control means and the brake traction control means is permitted, and the operation of the brake traction control means is prohibited when the vehicle speed is equal to or higher than the set vehicle speed. When the split road surface determination means determines whether or not the road surface is a split road surface, the set vehicle speed changing means determines the set vehicle speed by
It is changed depending on whether or not the split road surface is determined by the split road surface determination means.

Therefore, by prohibiting the brake traction control when the vehicle speed is equal to or higher than the set vehicle speed, it is possible to prevent the occurrence of the vehicle body vibration and the fade phenomenon of the brake mechanism due to the brake traction control when the vehicle speed is equal to or higher than the set vehicle speed. In addition, by changing the set vehicle speed according to whether the road is split or not, it is possible to determine whether the road is split or not in consideration of slip suppression and running stability, acceleration, durability of the brake mechanism, etc. The set vehicle speed can be changed accordingly.

[0021] Then, the set vehicle speed when the split road surface, so set higher than a set vehicle speed when it is not split road surface, to ensure slip suppression performance at the time of frequent split road traveling slip of one of the drive wheels Driving stability can be ensured .

[0022]

[0023]

[0024]

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 driving wheels. The driving torque of the V-type 6 cylinder engine 5 mounted on the front part of the vehicle body is changed by the tokule converter and the planetary gear type speed change. 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 arranged 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 21-24 composed of calipers 21b-24b for braking the rotation of these disks 21a-24a
(These correspond to a brake mechanism, respectively), and a brake control system for operating these brake devices 21 to 24 is provided.

[0026] In the brake control system, the hydraulic braking pressure depression force is pressurized from booster 26 is boosted by the booster 26 of the brake pedal 25 by the driver is supplied to the master cylinder da 27 tandem It The front wheel braking pressure supply pipe 2 extending from the master cylinder da 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 the 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.

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 that detects the amount of depression of the accelerator pedal 15, a throttle sensor 63 that detects the opening of the main throttle valve 16, and a mode switch 6 that sets a running mode (sport mode, normal mode, safety mode).
Sensors such as 4 are provided, and a traction control device 50 that performs 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 is provided. Each of the wheel speed sensors 51 to 54 is configured to detect a plurality of detecting portions formed on the brake discs 21a to 24a or the discs in the vicinity thereof with an electromagnetic pickup. Detection signals from the sensors and switches are supplied to the traction control device 50.
From the traction control device 50, the engine control device 6
0 is supplied with a control signal for engine traction control, and the electromagnetic opening / closing valves 31, 46, 36, 37,
A control signal for brake traction control is supplied to 39 and 40. The engine control device 60 controls the auxiliary throttle valve 17 via the actuator 18 based on a control signal for traction control. The engine control device 60 is supplied with various detection signals such as the vehicle speed, the opening of the main throttle valve, the engine speed, the intake air amount, and the shift position of the shift lever.

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 plurality of timers, and the like. The microcomputer ROM stores in advance a traction control control program, tables, maps, etc., and the RAM stores various work memories. Is provided.

The brake control will be briefly described.
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.

Next, traction control including engine traction control and brake traction control executed by the control device 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 traction control routine will be described with reference to the flowcharts of FIGS. Note that the reference symbol Si (i = 1, 2, 3 ...) In the figure indicates each step, and the main routine shown in FIG. 2 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 of the subroutines S1 to S5 will be described in order. Slip amount detection process ... See FIG. 3. When this slip amount detection process subroutine is started, the wheel speeds V1 to V1 of the left and right front wheels 1 and 2 and the rear wheels 3 and 4 are first 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 surface friction coefficient μ, a timer of 100 ms count and a timer of 500 ms count are used, and the vehicle speed V changes every 100 ms for 100 ms from the start of slip control until 500 ms when the vehicle body acceleration Vg does not become sufficiently large. Then, the vehicle body acceleration Vg is obtained from the following equation (1), and the vehicle body acceleration Vg becomes sufficiently large.
After 0 ms, the vehicle speed V for 500 ms every 100 ms
Then, the vehicle body acceleration Vg is obtained from the following equation (2). Note that V (i) is currently 100 as V (i-100).
ms before, V (i-500) is each vehicle speed before 500 ms, and K1 and K2 are predetermined constants. Note that ms is m
It is sec.

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.

[0040]

[Table 1]

Next, in S21, the map M0 of 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 is set.
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, target slip amount SET for throttle control
Is calculated as SET = basic value SETo × KD, and the target slip amount SBT for brake control is SBT = basic value SBTo ×
It is calculated as KD and these are stored in the work memory.

Slip determination processing: See FIG. 5. When the slip determination processing is started, various signals (slip amounts Se, Sb1, Sb2, target slip amount SET, SBT data, vehicle speed V, road surface μ, brake switch) Signal, etc.) is read (S30), and then, in S31 to S39, a slip flag Fe for identifying the necessity of engine traction control and a slip for identifying the necessity of brake traction control for the brake device 23 of the left rear wheel 3 A flag Fb1 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. If the determination is Yes, the slip flag Fe is set to 1 in S32, and then the process proceeds to S36. When the determination in S31 is No, it is determined in S33 whether the brake switch 59 is ON, and the determination is Yes.
If s, the process proceeds to S34, and the determination in S33 is N.
When it is o, the process proceeds to S35. In S34, the slip flags Fe, Fb1, Fb2 are all reset to 0, and then the process proceeds to S4. Brake switch 59 is O
When it is not N, in S35, the slip flag F
e is reset to 0, and then the road surface becomes a high μ road (for example, μ
≧ 3.0) is determined (S36), and when the road is a high μ road, S is determined.
If it is not a high μ road, the process proceeds to S37b.

Next, it is determined whether or not the vehicle speed V is equal to or higher than the set vehicle speed 60 km / h (S37a), and when the determination is Yes, that is, when the vehicle speed V is 60 km / h or higher, the brake traction control is prohibited. The slip flags Fb1, Fb
b2 is reset to 0 (S38), and then the process proceeds to S4. When the vehicle speed V is less than 60 km / h, S39
When Sb1> SBT, the slip flag Fb1
Is set to 1, and when Sb1 ≦ SBT, the slip flag Fb1 is reset to 0. And Sb2>
When SBT, the slip flag Fb2 is set to 1. When Sb2≤SBT, the slip flag Fb2 is reset to 0, and then the process proceeds to S4.

On the other hand, when the determination in S36 is No, that is, when the road is low μ, it is determined whether or not the vehicle speed V is equal to or higher than the set vehicle speed 40 km / h (S37b). If the determination is Yes, that is, the vehicle speed V is At 40 km / h or more, the slip flags Fb1 and Fb2 are set to 0 in order to prohibit the brake traction control.
Is reset to (S38), and then the process proceeds to S4. When the vehicle speed V is less than 40 km / h, the process proceeds to S39. As described above, on the high μ road, when the vehicle speed V is equal to or higher than the set vehicle speed 60 km / h, the slip flag Fb1,
Brake traction control is prohibited by resetting Fb2 to 0. If brake traction control is executed during high-speed traveling, vehicle vibration resulting from this will cause instability in traveling, and the braking devices 23 and 24 will be overloaded, causing a fade phenomenon. Brake traction control is prohibited when V is 60 km / h or more.

On the low μ road, the brake traction control is prohibited when the vehicle speed V is the set vehicle speed 40 km / h as described above. The reason why the set vehicle speed is changed according to the road surface μ is as follows. That is, high μ
This is because if the range of application of the brake traction control is not set wide on the road, the engine traction control will reduce the engine driving force too much and the acceleration performance will decline, so it will be prevented. 23,
This is because the overload of 24 causes a fade phenomenon and the durability of the brake devices 23, 24 is reduced. The set vehicle speeds of 60 km / h and 40 km / h are merely examples, and these are respectively set to Va (Va = 60 to 100 km / h).
h) and Vb (Vb = 40 to 70 km / h <Va) may be set.

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.

[0050]

[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 according to 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.

[0053]

[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).

[0057]

[Table 5]

The numerical values in Table 5 excluding the positive and negative signs are the duty ratio (%) of the duty solenoids of the solenoid on-off valves 36, 37, 39, 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 calculated by adding the basic control amount basic values Tb1 (i) and Tb2 (i) to the last final target control amounts FTbtg1 (i-1) and FTbtg2 (i-1) as shown in the illustrated arithmetic expression. ) 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 causes the initial closing motion 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 the present embodiment, as described above, when the vehicle speed V is less than the set vehicle speed 60 km / h on the high μ road, the engine traction control is performed. The brake traction control is allowed to suppress the slip of the drive wheels 3 and 4, so that the traveling is stabilized and the acceleration is secured. When the vehicle speed V is in the high-speed running state where the set vehicle speed is 60 km / h or more, the slip flags Fb1 and Fb2 are reset to 0, and the brake traction control is prohibited. If brake traction control is executed during high-speed traveling, vehicle vibrations will occur due to the brake traction control, and the brake devices 23, 2
Since 4 causes an overload and a fade phenomenon occurs and the performance and durability of the braking devices 23 and 24 deteriorate, the brake traction control is prohibited when the vehicle speed V is 60 km / h or more as described above. When the vehicle speed is 40 km / h or more on the low μ road, the brake traction control is prohibited.

That is, on a high μ road, the set vehicle speed can be set high and the applicable range of the brake traction control can be widened, so that it is possible to prevent the acceleration of the engine from being lowered due to the engine driving force being excessively reduced by the engine traction control. Further, by changing the set vehicle speed to a low value on a low μ road, the brake devices 23 and 24 are overloaded due to frequent brake traction control, a fade phenomenon occurs, and the performance and durability of the brake devices 23 and 24 are reduced. It is possible to prevent the deterioration.

Next, another embodiment in which the above embodiment is partially modified will be described .

[0066]

[0067] Another embodiment 1 ... Figure 1 5 References This embodiment is intended to modify the FIG. 5 of the embodiment as shown in FIG. 1 5, the other configurations are the same as in Example, Figure 1 is omitted five steps similar a of FIG 5 in the description are given the same step numbers, and only described step S36B changing. S after S35
In 36B, it is determined whether or not the road surface on which the vehicle is traveling is a split road (a road surface on which one half of the road surface is a low μ road and about half of the other surface is a high μ road), and when the determination is Yes, S37
If the result of S36B is No,
The process moves to S37b. Whether or not this is the split road is determined by the brake oil pressure P detected by the oil pressure sensors 55 and 56.
1 and P2, and when the difference between the brake oil pressures P1 and P2 is a predetermined value or more, it is determined to be a split road.

That is, on a split road, when the set vehicle speed is less than 60 km / h, the engine traction control and the brake traction control are allowed, and the set vehicle speed 60
Brake traction control is prohibited when the speed exceeds Km / h. In the case of a split road, since the slip amount of one of the drive wheels 3 and 4 increases frequently, the set vehicle speed is 6
Brake traction control is allowed up to 0 km / h, slipping of the drive wheels 3 and 4 is suppressed, and running stability can be secured. On the other hand, when the road surface is not a split road, it is a high μ road in the normal case and the need for traction control is not so high, so the set vehicle speed is 40 km / h.
In the above cases, prohibit the brake traction control,
When the speed is less than 40 km / h, the brake traction control is allowed. The set vehicle speed is 60km /
h and 40 Km / h are merely examples, and these are Va (Va = 60 to 100 Km / h) and Vb (Vb =
It may be set to 40 to 70 km / h <Va).

[0069]

[0070]

[0071]

[0072]

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] The steps after S36 in FIG. 5 are changed to provide a map in which a set vehicle speed that increases as the road surface μ increases is set, and the set vehicle speed is calculated based on the map and the road surface μ and set. The slip flags Fb1 and Fb2 may be reset to 0 at a vehicle speed equal to or higher than the vehicle speed.

[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.

FIG. 15 is a view corresponding to FIG. 5 according to another embodiment.

[Explanation of symbols]

1, 2 front wheels 3,4 rear wheels 23,24 Brake device 50 Traction control device 51-54 Wheel speed sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-141337 (JP, A) JP-A-2-262455 (JP, A) JP-A-5-1595 (JP, A) JP-A-5- 294225 (JP, A) JP-A 5-229414 (JP, A) JP-A 1-249557 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60K 41/00-41 / 28 B60T 8/58 F02D 29/00-45/00

Claims (2)

(57) [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. In a traction control device for a vehicle, a vehicle speed detecting means for detecting a vehicle speed, and when the vehicle speed detected by the vehicle speed detecting means is less than a set vehicle speed, the engine traction control means and the brake traction control means are allowed to operate, and the vehicle speed is equal to or higher than the set vehicle speed. In the case of, the traction regulating means for prohibiting the operation of the brake traction control means, the road surface friction detecting means for detecting the friction coefficient of the road surface, and the set vehicle speed are changed according to the road surface friction coefficient detected by the road surface friction detecting means. and a speed setting change means for, the Constant vehicle speed change means, set vehicle speed when the high-friction road surface
Is set higher than the set vehicle speed for low friction road surfaces.
A traction control device for vehicles, which is configured as described above . 2. A brake traction control means for performing brake traction control on the braking means and an engine traction control means for performing engine traction control on the engine in order to suppress slip of the drive wheels on the road surface. In a traction control device for a vehicle, a vehicle speed detecting means for detecting a vehicle speed, and when the vehicle speed detected by the vehicle speed detecting means is less than a set vehicle speed, the engine traction control means and the brake traction control means are allowed to operate, and the vehicle speed is equal to or higher than the set vehicle speed. In the case of, the traction control means for prohibiting the operation of the brake traction control means, the split road surface determination means for determining whether or not the road surface is a split road surface, and the set vehicle speed whether the split road surface is determined by the split road surface determination means or not. Change according to And a constant vehicle speed changing means, the speed setting change means setting when the split road surface
Set the vehicle speed higher than the set vehicle speed when the road surface is not split.
A traction control device for a vehicle, which is configured to be set quickly.