JPH01197160A - Brake controller of vehicle - Google Patents

Abstract

PURPOSE:To prevent wrong operation of antiskid control in a device provided with an antiskid control means and a traction control means by constituting the device such that traction control is not operated at the time of antiskid control. CONSTITUTION:This device has an antilock control means ABS controlling brake force so as to prevent each wheel from being locked upon brake operation; and a traction control means TRC controlling the drive torque of drive wheels for restraining the drive wheel (front wheels 2a, 2b) from being slipped by the drive torque. ABS has antilock modulator 16 while TRC a traction control actuator 14, and they are controlled by a common controller 6, which does not perform TRC control during ABS control operation. Interference between both control operations is prevented, thereby wrong ABS operation is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a braking control device for a vehicle that includes anti-skid control means and traction control means.

(Prior Art) Anti-skid control means that controls braking force to prevent wheels from locking when braking a vehicle generally detects the speed of each wheel and controls brake fluid pressure to each wheel based on this detection signal. This configuration is configured to maintain each wheel speed near a predetermined target slip ratio, but such a configuration requires a traction control system that controls the drive torque to suppress the drive wheels from slipping due to the drive torque. It has many similarities with the configuration of the control means. For this reason, a brake control device having both an anti-skid control means and a traction control means has been proposed, as disclosed in, for example, Japanese Patent Application Laid-Open No. 58-18947.

(Problems to be Solved by the Invention) However, when such a brake control device is employed, the following disadvantages may occur.

That is, in the anti-skid control means, a certain
When the wheel speed of one wheel becomes smaller than the vehicle speed estimated from the wheel speed of the other wheels and becomes less than a predetermined set value, or when the acceleration of a wheel becomes less than a predetermined negative set value, etc. On the other hand, in the traction control means, anti-skid control is started when the vehicle speed increases relative to the vehicle speed estimated from the driving wheel speed or the driven wheel speed and exceeds a predetermined set value, or when the driving Traction control is started when the acceleration of the wheels exceeds a predetermined set value. Therefore, if the operation parts of these two control means, that is, the brake fluid pressure supply path are shared, even during anti-skid control, when the driving wheel speed exceeds the above set value, or When the drive wheel acceleration exceeds the set value, traction control is started. However, the increase in drive wheel speed or drive wheel acceleration that occurs during anti-skid control is not due to the drive torque of the drive wheels;
Therefore, even if traction control is started, this is not the traction control that should be performed. Furthermore, the start of this traction control disturbs the brake fluid pressure that was properly controlled during anti-skid control, causing the anti-skid control means to malfunction.
This will result in negative effects such as the wheels locking up.

The present invention has been made in view of the above circumstances, and provides a brake control device that is capable of anti-skid control and traction control, and that can perform anti-skid control without being adversely affected by traction control. The purpose is to provide the following.

(Means for Solving the Problems) A vehicle brake control device according to the present invention is configured to perform no traction control during anti-skid control, thereby achieving the above object. That is, anti-skid control means controls the braking force so that the wheels do not lock when braking the vehicle, and traction control means controls the driving torque of the driving wheels so as to suppress the driving wheels from slipping due to the driving torque. A braking control device for a vehicle comprising a control means, wherein the traction control means is configured not to perform control when the anti-skid control means is performing control. It is.

The above-mentioned "trough shock control means" is "configured so as not to perform control when the anti-skid control means is performing control", and its meaning is as follows. In other words, it is configured not to start traction control during anti-skid control, and is configured not to start anti-skid control during traction control, or it is configured not to start anti-skid control during traction control. traction control. Therefore, for example, one controller may be used to perform anti-skid control and traction control, and the areas controlled by this controller may be separated, or both controls may be performed using separate controllers. However, when both controls are performed in a lap manner, the anti-skid control may be given priority. For example, a brake signal (whether or not the brake pedal is being depressed) can be used as a criterion for performing this anti-skid control with priority.

(Function) As shown in the above configuration, the traction control means is configured not to perform control when the anti-skid control means is performing control, so the anti-skid control means and the traction control means are not controlled. Even if a brake control device is configured to perform anti-skid control and traction control, the controls by both control means will not interfere with each other. In other words, a situation in which the traction control means malfunctions during anti-skid control is avoided, and this malfunction disturbs the properly controlled brake fluid pressure, causing the anti-skid control means to malfunction. Such a situation can be avoided.

(Effects of the Invention) Therefore, according to the present invention, anti-skid control and traction control can be performed with one brake control device, and anti-skid control can be performed without being adversely affected by traction control. .

(Examples) Examples of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram showing an embodiment of a vehicle braking control device according to the present invention.

This braking control device includes an anti-skid control means (hereinafter referred to as ABS) that controls the braking force so that the front wheels 2a, 2b and rear wheels 3a, :(b) do not lock when the vehicle is braked, and a Front wheel 2a, 2
The vehicle is equipped with traction control means (hereinafter referred to as TRC) for controlling the drive torque of the front wheels 2a and 2b so as to suppress each wheel b from slipping due to the drive torque.

The TRC includes acceleration slip detection means for detecting acceleration slip of the front wheels 2a, 2b, drive torque reduction means for reducing the drive torque of the front wheels 2a, 2b, and control means for controlling the drive torque reduction means. It has become.

The acceleration slip detection means of this TRC is the front wheel 2
A wheel speed sensor 4a detects the wheel speed of wheels a and 2b.

4b, and a controller 6 that calculates the acceleration/deceleration of the front wheels 2a, 2b based on the signals from these wheel speed sensors 4a, 4b. 2a, 2
brakes 8a, 8b provided in b, solenoid valves 10a, 10b, 12a, 12b,
It consists of a traction control actuator 14 and a hydraulic piping system connecting these. This hydraulic piping system is
It is almost commonly used with the ABS hydraulic piping system mentioned above.

The ABS includes an anti-lock modulator 16, a controller 6, and a hydraulic piping system. This AB
The S anti-lock modulator 16 includes a mask cylinder 18, brakes 8a and 8b for the front wheels 2a and 2b, and brakes 20a and 20 for the rear wheels 3a and 3b which are driven wheels.
This anti-lock modulator 16 is provided in the brake hydraulic pressure path connecting each wheel cylinder of 0b, and the anti-lock modulator 16 is connected to an accumulator 2 from a pump 24 driven by a motor.
Hydraulic pressure is supplied through the anti-lock modulator 6, and return oil from the anti-lock modulator 16 is collected in a reservoir 28. The anti-lock modulator 16 includes wheel speed sensors 4a for the front wheels 2a and 2b.
, 4b and rear wheels 3a, :3b wheel speed sensors 30
The brakes 8a, 8 for each wheel are controlled by the controller 6 based on the wheel speed signals from the wheels 8a, 30b.
Pressurizes, maintains, and depressurizes the hydraulic pressure supplied to the wheel cylinders 2a, 20a, and 20b, thereby maintaining the slip rate of each vehicle width 2a, 2b, 3a, and 3b near a predetermined target slip rate when braking the vehicle. Anti-skid control is provided. The anti-lock modulator 16 is composed of a solenoid valve and the like, but since its construction is generally well known, a detailed explanation will be omitted. The anti-lock modulator 16 is independently defined for each wheel, and between the two modulators for the rear wheels 3a, 3b and the mask cylinder 18, there are two anti-lock modulators 16 for the rear wheels 3a, 3b.
A bloportioning valve 32 is provided to reduce the hydraulic pressure supplied to the front wheels 2a, 2b compared to that to the front wheels 2a, 2b.

On the other hand, the TRC traction control actuator 14 is provided between the ABS anti-lock modulator 16 and the front wheel brakes 8a, 8b, and includes a right wheel actuator 14a and a left wheel actuator 14b. And these, each actuator 14a
, 14b is connected to a hydraulic path branching from the middle of the hydraulic path from the pump 24 to the ABS anti-lock modulator 16, and the solenoid valves 10a, lOb and dampers 34a, provided in this hydraulic path.
Hydraulic pressure from the pump 24 can be supplied to each actuator 14a, 14b via 34b. In addition, this oil pressure is applied to the solenoid valve 12a,
It is possible to escape to the reservoir 28 via 12b.

Solenoid valves 10a, 10b and 12a,
The valves 12b are normally closed and normally open, respectively, and are controlled to open and close by the controller 6. This opening/closing control is performed independently for the solenoid valves loa, 12a for the right wheel 2a and the solenoid valves 10b, 12b for the left wheel 2b, but since the same control is performed for both, For the right wheel 2a, when the solenoid valve 10a is open and the solenoid valve 12a is closed, it becomes a pressurized state where hydraulic pressure is supplied to the right wheel actuator 14a, and when the solenoid valve 10a is closed in this state, the pressure is applied to the actuator 14a. When the solenoid valve 12a is further opened in this state, the pressure is reduced to release the hydraulic pressure to the reservoir 28.

That is, the state returns to the illustrated state.

2a and 2b are diagrams showing the right wheel actuator 14a of the traction control actuator 14 in detail.

As shown in FIG. 2a, the actuator 14a includes a cylinder 36, a piston 38 housed in the cylinder 36, a rod 40, a seal ball 42, and a recessed plate 4.
4 and springs 46 and 48.

The piston 38 and the recessed plate 44 are connected to the spring 4
6 to both ends of the cylinder 3B. Then, the hydraulic pressure from the solenoid valve 10a is applied to the end of the cylinder 36 on the piston 38 contact side.
A hole 50 for supplying hydraulic pressure from the anti-lock modulator 1G to the recessed plate 44 is formed at the end of the cylinder 36 that contacts the recessed plate 44.
A hole 52 for supplying the hydraulic pressure in the cylinder 36 to the rear of the brake 8a and a hole 54 for supplying the hydraulic pressure in the cylinder 36 to the wheel cylinder of the brake 8a are formed. The rod 40 has large diameter portions at both ends, one end of which is biased leftward in the figure by a spring 48, and the other end of which is locked by a stopper portion 38a formed on the piston 38. 40's movement to the left is restricted. A seal ball 42 is disposed at one end of the rod 40 at a position facing the hole 52 of the cylinder 36. Further, a hole 56 is formed in the concave plate 44 to allow the hole 52 and the hole 54 to communicate with each other.

To explain the action of the actuator 14a, the second
As shown in Fig. a, when no hydraulic pressure is supplied from the solenoid valve 10a, the piston 38 rests in contact with the right end wall of the cylinder 36 due to the spring 46. At this time, the rod 40 is maintained at the illustrated position by the stopper portion 38a of the piston 38 against the spring force of the spring 48. As a result, the seal ball 42
A gap is formed between the anti-lock modulator 16 and the hole 52, and the hydraulic pressure from the anti-lock modulator 16 flows through the holes 52, 58, 5.
4, it can be freely supplied to the brake 8a.

On the other hand, as shown in FIG. 2b, the solenoid valve 10a
When hydraulic pressure is applied behind the piston 38, the piston 38 slides to the left within the cylinder 36.

Along with this, the rod 40 also moves to the left due to the spring force of the spring 48, and when the rod 40 moves a predetermined distance, the rod 40
A seal ball 42 arranged at the left end of the hole 52 closes the hole 52. Even if the piston 8B moves further to the left, the rod 40 maintains the position shown in the figure, so that the hydraulic pressure trapped in the cylinder 36 by the seal ball 42 is applied to the brake 8a through the hole 54 while being pressurized by the piston 38. Supplied. As mentioned above, the hydraulic pressure supplied to the brake 8a is controlled to open and close the solenoid valves lOa and 12a to adjust the hydraulic pressure supplied to the back of the piston 38, so that the pressurizing, holding, and depressurizing states can be controlled. It is possible to select as appropriate.

However, even if the hole 52 is closed by the seal ball 42, if hydraulic pressure higher than a predetermined pressure is supplied from the anti-lock modulator 16 to the hole 52 due to depression of the brake pedal 58 (see FIG. 1), etc. This oil pressure is applied to the seal ball 42 against the spring force of the spring 48.
Push up the brake 8a1. :P- is to be supplied.

The controller 6, which is commonly used by the ABS and TRC, is configured so that once either the ABS or the TRC starts controlling, it does not perform control until the control is completed.

Next, the action of ABS will be explained based on FIGS. 1 and 3.

First, when the brake pedal 58 is depressed to brake the vehicle, the wheel cylinder of the brake 8a (the other brake 8
The same applies to wheel cylinders b, 20a, and 20b. ) is pressurized and the brake fluid pressure applied to (a
- b) The wheel speed decreases. When the difference between the wheel speed and the vehicle body speed increases and the deceleration of the wheel 2a exceeds the set value ('bo) (point A), a holding current is output to the anti-lock modulator 16, and the brake fluid pressure is held in that state. (between b and c).

The difference between the wheel speed and the vehicle body speed increases, and the wheel speed reaches the set value (
B), the controller 6 determines that the wheel 2a is in the direction of locking, and the anti-lock modulator 1
At step 6, a pressure reduction signal is output so that the brake fluid pressure decreases, thereby reducing the pressure in the wheel cylinder (c
- d). By reducing the pressure, when the deceleration of the wheel 2a returns to the set value (-bo) (0 point), a holding signal is output to maintain that hydraulic pressure again, and the brake hydraulic pressure is maintained (between d and e). ). Wheel speed recovers while the hold condition is maintained. When the wheel speed increases and the acceleration of the wheel 2a exceeds the set value (+b2o) (point D), the controller 6 determines that the wheel speed has sufficiently recovered and outputs a signal to increase the pressure in the wheel cylinder again (e - f).

By increasing the pressure, the acceleration of the wheel 2a reaches the set value (+b
2o), it outputs a holding signal (point E) (f-
g). When the acceleration of the wheel 2a falls below the set value (+b+o), the pressure is increased until it exceeds the set deceleration value (bo).
Repeat holding to control brake fluid pressure (g-
h interval). When the deceleration of the wheel 2a exceeds the set value (bo) (point F), the above-described cycle is repeated to control the brake fluid pressure. The set value of the acceleration/deceleration of the wheel 2a (-bOl +blot +b2o) is the wheel 2a
This value is set to maintain the rotational speed of the motor around a predetermined target slip ratio. With the above anti-skid control,
The wheels 2a rotate in a state where a sufficiently large braking force is obtained between the wheels 2a and the road surface.

Next, the action of TRC will be explained.

In Figure 1, when the vehicle starts, etc., the front wheels 2, which are the driving wheels,
Since the front wheels 2a and 2b are driven and acceleration slip occurs in these front wheels 2a and 2b, this acceleration slip is detected as acceleration/deceleration by the acceleration slip detection means. That is, the wheel speeds of the front wheels 2a, 2b are detected by the wheel speed sensors 4a, 4b, and the acceleration/deceleration of the front wheels 2a, 2b is calculated by the controller 6 based on these detection signals. This acceleration/deceleration causes acceleration slip of the front wheels 2a and 2b (that is, the front wheels 2a and 2b).

2b) is detected.

At this time, the deceleration slip (i.e., the front wheel 2
Slips in which the slip rates of a and 2b are negative are also detected. Since the acceleration slip detection described above and the traction control described below are performed independently and similarly for each of the front wheels 2a and 2b, the right wheel 2a will be explained.

When the acceleration of the right wheel 2a is equal to or higher than a predetermined set value, the controller 6 does not control the drive torque reducing means. That is, the solenoid valves 10a, 1
2a is in the closed and open states as shown, no hydraulic pressure is supplied to the actuator 14a, and therefore no hydraulic pressure is supplied from the actuator 14a to the brake 8a. When the acceleration exceeds the set value, the controller 6 starts controlling the drive torque reducing means. That is, when the acceleration of the right wheel 2a exceeds the above set value, the controller 6 energizes the solenoid valves 10a and 12a to switch them to the open and closed states, respectively, and turns the pump 2 on.
4 is supplied to the actuator 14a. As a result, the actuator 14a enters a pressurized state in which the hydraulic pressure in the cylinder 3B is sent to the brake 8a, as shown in FIG. 2b. By maintaining this pressurized state for a predetermined period of time, it becomes possible to suddenly pressurize the brake 8a, thereby rapidly braking the right wheel 2a by the brake 8a, and causing the driving torque of the right wheel 2a to decrease rapidly.

As shown in FIG. 4, the sudden pressurization is expressed as a graph of a linear increase in brake pressure. Further, as shown in this graph, after the sudden pressurization, the following control is performed depending on the acceleration/deceleration of the right wheel 2a.

That is, when the acceleration exceeds the set value (tx), the hydraulic pressure supplied to the brake 8a is increased, and the set value (tl) is increased.
When the deceleration exceeds the set value (tl), the pressure is reduced, and when the acceleration/deceleration is between the set values (tl) and (tl), the supplied hydraulic pressure is maintained. The pressurization and depressurization operations after the first sudden pressurization operation are performed gradually in order to prevent unpleasant vehicle body vibrations due to hunting.

That is, the pressure is applied in stages by holding the pressure between the pressurizations (or by holding the pressure between the depressurizations).

Next, the operation of this embodiment will be explained.

As shown in Figure 3, the ABS starts anti-skid control at point A, where the wheel deceleration reaches the set value (bo), and thereafter controls the brake fluid pressure to obtain the acceleration/deceleration curve shown. As already mentioned, during this anti-skid control, the acceleration of the wheels may exceed the set value (tl) that is the starting condition for traction control (point G). If such a situation occurs while anti-skid control is being applied to the front wheels 2a and 2b, which are the driving wheels, the brake fluid pressure will increase as shown by the two-dot chain line in the figure due to the start of traction control. Then, the acceleration of the wheels suddenly decreases as shown by the two-dot chain line in the figure, and the wheels may become locked.

However, in this embodiment, ABS and TR
A controller 6 commonly used for ABS and T
Since the configuration is such that when one of the RCs starts controlling the other, it does not control the other until the control is completed, so interference between these two controls is avoided, and even in the above case, anti-control is prevented. Skid control will continue to be carried out sympathetically.

As a condition for the controller 6 to start anti-skid control or traction control, in addition to the wheel acceleration/deceleration setting value as described above, a wheel slip rate setting value can be adopted.

FIG. 5 is a graph showing an example in which the set value of the wheel slip rate is used as the starting condition for anti-skid control and traction control. That is, when the slip ratio becomes smaller than a predetermined set value (So) (point P), anti-skid control is started, and when the slip ratio becomes larger than the set value (+Ss), traction control is started (point Q). It is something that can be done. Also in this case, according to this embodiment, mutual interference between the two controls is avoided by the controller 6.

FIG. 6 is a flowchart showing the control by the controller 6 when the wheel acceleration/deceleration setting value and the slip rate setting value are used together as the starting conditions for anti-skid control and traction control.

As shown in the figure, when the wheel acceleration/deceleration or slip rate exceeds a set value (bo) or (So), traction control is prohibited and anti-skid control is started. After this anti-skid control is completed, when the acceleration/deceleration or slip rate of the wheels exceeds the set value (+b2o), (181), traction control is started. Then, when this traction control ends, the vehicle returns to the initial state again.

Therefore, when either anti-skid control or traction control is started, the other control is not performed until that control is completed.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram showing one embodiment of a vehicle braking control device according to the present invention, Figs. 2a and 2b are enlarged views of main parts of Fig. 1, and Figs. 3, 4, and 5 show the operation of the device. The graph shown in FIG. 6 is a flowchart showing the operation of the device. 2a, 2b...Front wheel (driving wheel) 3a, 3b...Rear wheel (driven wheel) 4a, 4b, 8.1B, 24.2B, 28.30a, 3
0b, 32...Anti-skid control means (ABS) 4
a, 4b, 8.8a, 8b, 10a, 10b, 12a,
12b, 14.24.28°28.34a, 34b-)
- traction control means (TRC) 4a, 4b, 30a,
30b--Wheel speed sensor 6...Controller 8a, 8b, 20a, 20b--Brake 10a, l
Ob, 12a, 12b--Solenoid valve 14...
・Traction control actuator 1B...Anti-lock modulator 24...Pump 26...Accumulator 28...Reservoir 32...Provisioning valves 34a, 34b--Danha Fig. 2a Fig. 4 Figure 5: Figure 6

Claims (1)

[Scope of Claims] Anti-skid control means for controlling braking force so that the wheels do not lock when the vehicle is braked; and anti-skid control means for controlling the driving torque of the driving wheels so as to suppress the driving wheels among the wheels from slipping due to the driving torque. In the braking control device for a vehicle, the traction control means is configured not to perform control when the anti-skid control means is performing control. Features of vehicle braking control device.