JP3138086B2 - Brake control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
More particularly, the present invention relates to a brake control device that improves the adhesion performance of a wheel by appropriately reducing, holding, and returning a braking force during wheel sliding.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to the drawings.
FIG. 9 is a diagram showing a configuration of a conventional brake control device.
First, rotation speed pulses, which are outputs of a speed sensor attached to the axle, are counted by the speed calculation means 11 to 14 for a certain period of time, thereby calculating the rotation speed of the axle (hereinafter simply referred to as speed). Next, acceleration is calculated from the difference between the current speed calculation value and the speed calculation value a fixed time ago by the acceleration calculation means 21 to 24. The reference speed calculating means 4 sets the maximum value of the speeds of the plurality of axles as the reference speed, and the sliding speed calculating means 51 to 54 calculates the sliding speed which is the difference between the reference speed and the rotation speed. Lastly, the determination command means 61 to 64 determine the sliding speed and the acceleration based on the acceleration and reduce the braking force.
Hold and return.

FIG. 10 is a graph showing changes in speed, acceleration and braking force in an example of normal brake control when a gliding occurs. In FIG. 10, the lowermost row represents the braking force, and the brake control operations of starting, lowering, holding, and returning are linked in order from left to right in the figure. “Start-up” is an operation of gradually increasing the braking force to apply a brake to the vehicle. "Reduction"
When the brakes are applied too much and the wheels start sliding on the rails, the braking force is reduced to stop the sliding. “Holding” is an operation in which the braking force is kept constant in order to suppress an excessive decrease in the braking force, for example, when the sliding starts to stop. “Return” is an operation of increasing the braking force again when there is no danger of gliding.
In this case, the sliding is detected when, for example, the sliding speed reaches a certain value at the point a, and the braking force is reduced. Next, at point b, the braking force is held at a constant value, for example, when the acceleration is greater than or equal to a certain value, and at point c, for example, the braking force is restored when the sliding speed is less than a certain value.

In the prior art, there are the following problems in each phase of brake control. Since the start of the run or the determination of the fear at the time of startup or the like is performed only based on the information on the run speed and the acceleration, a time delay occurs in the determination, and the run speed has to be increased.

[0005] Since the braking force is continuously increased at the time of starting, the braking force is increased until the sliding is detected, which further promotes the sliding. At the same time, the average braking force was reduced because the braking force was reduced by the slippage detection. On the other hand, even if the threshold value of the slide detection is lowered to make it easier to detect the slide, the braking force is similarly reduced. In addition, in the case of a mechanical brake, a hydraulic source or an air source is consumed more than necessary due to the sliding.

[0006] Since the determination of the calmness of the sliding state at the time of lowering is performed only based on the information on the sliding speed and the acceleration, a time delay occurs in the determination, and the braking force is reduced more than necessary, and the average braking force decreases. I was

[0007] If the transition from the holding to the return is delayed, the transition from the sliding to the re-adhesion becomes sharp, so that at the time of the re-adhesion, the rise of the braking force becomes insufficient, and the force between the wheel and the rail (hereinafter, referred to as the force). (Referred to as TER-91- material of the Institute of Electrical Engineers of Japan).
43).

[0008] Since the judgment of the possibility of the end of the sliding state at the time of holding is performed only by the sliding speed and the acceleration, a time delay occurs in the determination, and when the sliding ends (re-adhesion), the rise of the braking force becomes insufficient, There was the same problem as above. In addition, the average braking force was reduced due to insufficient rise of the braking force.

[0009] Since the braking force is returned to the original value at a stretch at the time of returning, it often happens that the vehicle slides again when the braking force almost reaches the value at the time of the previous sliding.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to start, calm down,
Providing a brake control device with improved wheel adhesion performance that can determine the expected end without any time delay, and can start, reduce, hold, and return the braking force at an appropriate timing and without overaction. The purpose is to do.

[0011]

A brake control device according to a first aspect of the present invention receives an axle rotation pulse as an input signal, processes the signal to determine a sliding state of a wheel with respect to a rail. A brake control device for controlling a rise, a reduction, a hold or a return of a braking force according to a state; a speed calculation means for calculating an axle rotation speed using an axle rotation pulse; and a current axle rotation speed. Acceleration calculating means for calculating the acceleration from the difference between the current value and the previous value; acceleration differential calculating means for calculating the differential acceleration value from the difference between the current value of the acceleration and the previous value; and a reference representing the speed of the vehicle reference speed generating means and for generating a speed; reference speed and the sliding speed calculation means for calculating a sliding speed is the difference between the axle rotation speed; during start-up or start-up the middle holding, sliding speed First determination command means for determining the start of the gliding state by using three conditions where the acceleration is equal to or more than a certain value, the acceleration is equal to or less than a certain value, and the acceleration differential value is equal to or less than a certain value, and issues a command to reduce the braking force. It is characterized by doing.

In this embodiment, the start of the sliding state is determined while considering the acceleration differential value, that is, predicting the acceleration, in order to determine the timing for reducing the braking force, so that the delay in the reduction timing is small. Therefore, the gliding speed can be kept lower .

[0013] A brake control device according to a second aspect of the present invention.
Receives the axle rotation pulse as an input signal and receives the signal.
By processing, the sliding state of the wheel against the rail
Judgment, and according to the state,
A brake control device that controls lowering, holding, or returning.
I; with a rotation pulse of the axle to calculate the axle rotation speed
Speed calculation means; current value and previous value of axle rotation speed
An acceleration calculating means for calculating an acceleration from the difference between; acceleration
Calculate the acceleration differential value from the difference between the current value and the previous value of
Acceleration differential value calculating means; a reference speed representing the speed of the vehicle
Reference speed generating means for generating speed; reference speed and axle rotation speed
A sliding speed calculating means for calculating a sliding speed which is a difference in degrees;
When starting up or returning, the gliding speed must be lower than a certain value.
Above, or the acceleration is below a certain value, or the acceleration differential value is
It is also possible that two or more conditions below a certain value are satisfied at the same time.
To judge the signs of the start of skiing, and reduce the braking force for a certain period of time.
It is characterized by comprising second determination command means for issuing a command to hold the value at a constant value .

[0014] In this aspect, the threshold value is lower than the threshold value for judging the start of gliding, and by detecting the signs of gliding when the braking force is started, the braking force is kept constant, thereby suppressing the progress of gliding. be able to.

In the brake control device according to a third aspect of the present invention, instead of the second determination instructing means, at the time of lowering during skiing, the acceleration is not less than a certain value and the acceleration differential value is not less than a certain value. It is characterized in that it is provided with a third judgment command means for judging the calmness of the sliding state on the basis of the fact, and issuing a command for maintaining the braking force.

In this embodiment, the calmness of the sliding state is determined in consideration of the differential acceleration value, that is, the prediction of the acceleration, in order to determine the timing of holding the braking force. Therefore, a decrease in braking force can be minimized.

The brake control apparatus according to a fourth aspect of the present invention comprises a means for calculating the acceleration differential predicted value from the acceleration differential value and its preceding value in addition to the above various means; Furthermore, the second In place of the determination command means, at the time of lowering during sliding, when the acceleration is equal to or more than a certain value and the predicted acceleration differential value is equal to or more than a certain value, it is determined whether the sliding state is calm and a command to hold a braking force is issued. It is characterized by comprising four determination command means.

In this embodiment, since the calmness of the sliding state is determined in consideration of the acceleration differential prediction value in order to determine the timing of holding the braking force, the delay of the holding timing is reduced, and therefore, the reduction of the braking force is reduced. Can be minimized.

A brake control device according to a fifth aspect of the present invention receives an axle rotation pulse as an input signal, processes the signal to determine a sliding state of a wheel with respect to a rail, and determines a braking force according to the state. A brake control device for a railway vehicle for controlling start-up, pull-down, holding or return of a vehicle; speed calculating means for calculating an axle rotation speed using an axle rotation pulse; Acceleration calculation means for calculating an acceleration from the difference between the vehicle speed and the vehicle speed; reference speed generation means for generating a reference speed representing the speed of the vehicle; and sliding speed calculation means for calculating a sliding speed which is a difference between the reference sequence and the axle rotation speed. And at the time of holding, when the acceleration has become equal to or more than a certain value, the possibility of ending the sliding state is determined, and a command to hold again after returning the braking force for a certain time is issued. Characterized by comprising a; a fifth determination command means.

In this embodiment, if the braking force is raised for a certain period of time and held again before the condition from the holding of the braking force to the return is satisfied, the speed of the transition from the sliding to the re-adhesion can be reduced. As a result, the fluctuation of the tangential force at the time of re-adhesion can be reduced.

In the brake control device according to the sixth aspect of the present invention, instead of the second determination instructing means, the skiing is performed when the acceleration is positive and the acceleration differential value is changed from positive to negative during holding. It is characterized in that it comprises a sixth judgment command means for judging an end possibility of the state and issuing a command to return the braking force.

When the acceleration is positive and the differential acceleration value changes from positive to negative during holding, it can be determined that the transition from sliding to re-adhesion is slight, and the sliding speed is equal to or less than a certain value. Thus, when the brake force is restored, the timing of the brake force return can be more accurately determined. Therefore, it is possible to suppress the variation in the braking force at the time of re-adhesion and to further suppress the variation in the tangential force at this time.

A brake control device according to a seventh aspect of the present invention includes, in addition to the above-described means, means for calculating a predicted sliding speed after a predetermined time from the current sliding speed, acceleration, and differential acceleration value. Further, instead of the second determination instructing means, when holding, when the sliding speed predicted value has become equal to or less than a certain value, it is determined that the sliding state is expected to end,
Eighth determination command means for issuing a command to return the braking force is provided.

The sliding state is predicted in advance based on the predicted sliding speed, and the braking force can be restored without time delay. Therefore, the same operation as in the sixth embodiment is performed.

A brake control device according to an eighth aspect of the present invention, in addition to the above-mentioned various means, means for calculating a secondary acceleration differential value from a difference between a current value and a previous value of the acceleration differential value; current planing speed, acceleration, and means for calculating a sliding speed prediction value after a predetermined time from the acceleration differential value and the acceleration second derivative; comprises a further, in place of the second determination command means, the time of retention In, when the predicted sliding speed is less than or equal to a certain value, the possibility of ending the sliding state is determined,
Eighth determination command means for issuing a command to return the braking force is provided.

Since the second derivative of acceleration is also taken into account in the calculation of the predicted sliding speed, the future sliding speed can be more accurately predicted.

In the brake control device according to a ninth aspect of the present invention, instead of the second determination command means, at the time of return, the brake force is restored for a certain time, and then the brake force is held for a certain time. It is characterized by having a command means for issuing a command to gradually restore the braking force by repeating this.

Since the braking force is gradually increased, it becomes difficult to glide. Even if the glide occurs with the increase in the braking force, the progress of the glide is slowed down because there is little surplus torque exceeding the force between the wheels and the rails. Sliding detection and subsequent response become easier.

A brake control device according to a tenth aspect of the present invention includes, in addition to the above-described various means, means for calculating a predicted sliding speed after a predetermined period of time from the current sliding speed, acceleration, and differential acceleration value; Means for calculating an acceleration predicted value after a predetermined time from the acceleration and the acceleration differential value; and, in place of the second determination command means, at the time of start-up or at the time of holding during start-up, And / or ninth judgment command means for judging the start of the sliding state in consideration of the predicted sliding speed or the predicted acceleration value to the acceleration and issuing a command to reduce the braking force.

The brake control device according to an eleventh aspect of the present invention includes, in addition to the above-mentioned various means, means for calculating a predicted sliding speed after a certain period of time from the current sliding speed, acceleration, and differential acceleration. Further, in place of the second determination command means, when the vehicle is started up or held during the start-up, the predicted sliding speed is equal to or more than a certain value, or additionally, the acceleration is equal to or less than a certain value. A tenth determination command means for determining the start of the sliding state and issuing a command to reduce the braking force is provided.

The advantages of the ninth and tenth aspects of the brake control device are as follows. There are more or less delays in calculating speed and acceleration. Also, there is a delay in starting, lowering, holding, and returning the brake until a command is issued and the braking force changes. By using the predicted value of the sliding speed or the predicted value of the acceleration after an appropriate time (Δt) instead of the sliding speed or the acceleration, it is possible to more accurately determine the sliding state and more accurately match the timing of the braking operation.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the first aspect of the present invention will be described with reference to FIG. Speed calculating means 11 is obtained from the number of axle rotation pulses input within a certain time and the total pulse width thereof.
１４14 is used to calculate the speed. Since the speed calculation accuracy can be remarkably improved by using this speed calculation method as compared with the conventional speed calculation method, it is preferable to use this method in each aspect of the present invention. Next, the acceleration calculation means 21 to 21
Using 24, the acceleration is calculated from the difference between the current speed and the speed a fixed time ago. Further, acceleration differential value calculation means 31 to 3
4 is used to calculate an acceleration differential value from the difference between the current acceleration and the acceleration before a predetermined time. Further, the reference speed is calculated from the maximum value of the speed of each axis by using the reference speed calculating means 4. When all the axes have slid, a deceleration preset by a brake notch and a traveling speed and a new reference speed from the previous reference speed are calculated. Next, the running speed of each axle is calculated from the difference between the reference speed and each axle rotation speed using the running speed calculating means 51 to 54.

Next, using the discrimination command means 61 to 64, the start of the sliding state is determined at the time of start-up or holding during the start-up from the above-mentioned slide speed, acceleration, acceleration differential value, and reference speed, and the braking force is reduced. Determine the timing. The timing for lowering the braking force is, for example, that the sliding speed is equal to or higher than a certain value and the acceleration or acceleration differential value is equal to or lower than a certain value, or that the sliding speed is equal to or higher than a certain value and the acceleration differential value is equal to or lower than a certain value. decide.

FIG. 2 is a graph showing changes in speed, acceleration, and braking force during brake control in the brake control apparatus according to the first embodiment of the present invention. At the uppermost speed, the solid line to the right indicates the reference speed, and indicates a state in which the vehicle is decelerating at a substantially constant rate. The alternate long and short dash line represents the speed (axle rotation) in the case of the conventional technique, and there is a large difference (sliding speed) between the reference speed and the speed in the section b. The reason for this is that, as shown in the lowermost braking force, the timing a for lowering the braking force is delayed. On the other hand, in the present embodiment, a ′
At this point, the value of the acceleration (middle stage) and its differential value are equal to or less than a certain value, that is, since the wheels start to slide and decelerate steadily, the start of the sliding state is determined early to reduce the braking force. As a result, the absolute value of the sliding speed is extremely small even at the point b 'where the sliding speed is maximum.

An embodiment according to the second aspect of the present invention will be described with reference to the drawings. FIG. 3 shows an embodiment in which a slight gliding is detected when the braking force starts up, for example, by detecting that the acceleration is equal to or less than a threshold value (a 'in the figure), and the braking force is kept constant. Any of the sliding speed and the axle acceleration is used as the normal sliding detection, that is, the detection for lowering the braking force. For example, a differential value of the axle acceleration can be used in combination with the axle acceleration. The threshold value for maintaining the braking force at a constant value is set to be higher in sensitivity than the threshold value for normal sliding detection. Then, after maintaining the braking force at a constant value for a certain period of time, the braking force is increased again. By doing so, the running speed is kept at a very small value, and the coefficient of friction between the wheels and the rails is not greatly reduced.

FIG. 3 shows the case where the braking force is raised. However, when the braking force is recovered during the gliding, the braking force is increased with a threshold having a higher sensitivity than the normal sliding detection threshold value as in the case of the rising. Is stopped, and the braking force is maintained, as compared with the case where the braking force is continuously increased, the sliding detection does not increase again, the return detection threshold is reached again, and the possibility that the braking force can be restored is increased.

Embodiments according to the third and fourth aspects of the present invention will be described with reference to the drawings. In FIG. 4B, the calmness of the sliding state is determined, and the reduction of the braking force is stopped and held. The holding timing is determined based on, for example, that the acceleration differential value is equal to or more than a certain value and the acceleration is equal to or more than a certain value. Note that the timing can be determined based on the predicted value of the acceleration differential value. In this embodiment, the braking force is not reduced more than necessary, and the vehicle can be decelerated more quickly by increasing the average value of the braking force.

An embodiment according to the fifth aspect of the present invention will be described with reference to the drawings. FIG. 5 shows an embodiment in which the braking force is raised for a certain period of time and held again when the acceleration becomes positive during the holding of the braking force. In this case, in addition to the conventional brake control shown in FIG. 10, the braking force is raised for a certain period of time when, for example, the acceleration is positive at point b '. Note that the threshold value of the acceleration at the point b ′ may be a constant negative or positive value depending on the situation, or the threshold value may be dynamically changed. It can be appropriately selected according to the vehicle speed, the type of the brake, and the like.

Embodiments according to the sixth, seventh and eighth aspects of the present invention will be described with reference to the drawings. FIG. 6 shows an embodiment in which the braking force is restored when the acceleration is positive and the acceleration differential value becomes negative while the braking force is held, and the braking force is restored at the point c ′. In this case, since the acceleration tends to decrease, the frictional force between the wheel and the rail,
That is, since the tangential force is detected to have returned, the speed at which the transition from sliding to re-adhesion is reflected and the braking more accurately than when the brake recovery is detected using only the current value of the sliding speed in the past. Determines the timing of the return of the force.

In the case of the seventh embodiment, the predicted sliding speed Vp after a predetermined time from the current sliding speed V, acceleration α, and acceleration differential value J is calculated in consideration of the time delay of the brake control. The brake recovery is detected based on the fact that the value becomes equal to or less than a predetermined value. Specifically, time △ gliding speed prediction value after t seconds V _p is, for example, _{V p = V + α * △} t + 0.
It is expressed as 5 * J * (Δt) ² . Therefore, it can be said that the detection is intended to be performed more accurately than in the case of the sixth embodiment because the acceleration differential value is used. In practice, this accuracy depends on the accuracy of calculating the acceleration differential value.

In the case of the eighth embodiment, taking into account the time delay of the brake control, the sliding speed after a certain time from the current sliding speed V, acceleration α, acceleration differential value J and secondary acceleration differential value △ J is considered. A predicted value is calculated, and when the value becomes equal to or less than a predetermined value, the brake recovery is detected. Specifically when ignoring the effect of the time △ sliding velocity predicted value V _p of t seconds after the example of the vehicle acceleration _{V p = V + α * △} t + 0.5
* J * (Δt) ² + (ΔJ / 6) * (Δt) ³ Therefore, it can be said that the detection is intended to be performed more accurately than in the case of the seventh embodiment because the second derivative of the acceleration value is used. In practice, this accuracy depends on the accuracy of calculating the acceleration differential value and the acceleration secondary differential value, and the validity of linearly approximating the change in the acceleration differential value.

An embodiment according to the ninth aspect of the present invention will be described with reference to the drawings. FIG. 7 is a diagram showing an embodiment of the brake control according to the aspect. During the holding of the braking force, the return of the braking force is detected, for example, when the sliding speed is equal to or lower than a predetermined value (C). In the conventional method, the braking force is immediately increased at this point, but in the present invention, as shown in the "return" portion on the right side of the lower braking force in the figure, the braking force is held for a certain time after being started for a certain time. And so on.

FIG. 8 is a view showing another embodiment of the present embodiment. In FIG. 7, the braking force return time and the holding time are fixed, but the braking force return time (T ₁ , T _1
3 ) If the holding time (T ₂ , T ₄ ) can be set, an appropriate value of the braking force can be determined according to the type of the brake and the like.

[0044] In the tenth and eleventh aspect, sliding velocity predicted value V _p and the acceleration prediction value alpha _p If ignoring the effect of acceleration of the vehicle is calculated by the following method. V _p = V + α · Δt or V _p = V + α · Δt + 0.5 * J * (Δt) ² α _p = α + J · Δt where V is the current calculated sliding speed, α is the same acceleration, J
Is the acceleration differential value, and Δt is the predicted time.

[0045]

According to the first, tenth and eleventh aspects of the present invention, the start of gliding can be determined without time delay, and the braking force can be reduced quickly, so that the gliding speed can be suppressed to a low level. Can be provided.

According to the second aspect of the present invention, it is possible to suppress the progress of the sliding at the time of raising the braking force,
Moreover, since there is no reduction in braking force,
It is possible to provide an economical brake control device without wasting the hydraulic pressure source or reducing the air.

According to the third and fourth aspects of the present invention, it is possible to determine and maintain the calmness of the sliding state when the braking force is reduced without time delay, so that it is possible to prevent excessive reduction and increase the average braking force. it can.

According to the fifth aspect of the present invention, in the brake control at the time of sliding, the speed of shifting from sliding to re-adhesion can be reduced, and the return timing can be easily determined. Variations in the tangential force at the time can be reduced.

According to the sixth, seventh and eighth aspects of the present invention, in the brake control at the time of sliding, the timing of the sliding can be more accurately determined, and the brake control at the time of sliding can be more appropriately performed. It is possible to provide a brake control device in which the tangential force at the time of re-adhesion is small and the average braking force during the run is small.

According to the ninth aspect of the present invention, it is possible to prevent the skiing again by gradually returning the braking force to a predetermined value by detecting the braking force return during the skiing.
In addition, even if a slide occurs, there is an advantage that the progress of the slide is slowed and the slide speed is reduced.

As described above, according to the present invention, it is possible to provide a brake control device having a low running speed, a high average braking force, and excellent adhesion performance suitable for a high-performance vehicle. As a result, not only can the traveling speed of the vehicle be improved, but also damage to the vehicle and the traveling road due to gliding can be kept to a minimum, and the economic effect of vehicle maintenance is great.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a brake control device according to an embodiment of the present invention.

FIG. 2 is a graph showing changes in speed, acceleration, and braking force during brake control in the brake control device according to the embodiment of the first aspect of the present invention.

FIG. 3 is a graph showing changes in speed, acceleration, and braking force during brake control in a brake control device according to an example of the second aspect of the present invention.

FIG. 4 is a graph showing changes in speed, acceleration, and braking force during brake control in a brake control device according to an example of the third and fourth aspects of the present invention.

FIG. 5 is a graph showing changes in speed, acceleration, and braking force during brake control in the brake control device according to the example of the fifth aspect of the present invention.

FIG. 6 is a graph showing changes in speed, acceleration, and braking force during brake control in the brake control device according to the sixth, seventh, and eighth aspects of the present invention.

FIG. 7 is a graph showing changes in speed, acceleration, and braking force during brake control in the brake control device according to the ninth embodiment of the present invention.

FIG. 8 is a graph showing changes in speed, acceleration, and braking force during brake control in a brake control device according to another embodiment of the ninth aspect of the present invention.

FIG. 9 is a block diagram showing a configuration of a conventional brake control device.

FIG. 10 is a graph showing changes in speed, acceleration, and braking force during brake control in a conventional brake control device.

[Explanation of symbols]

 4 Reference speed generation means 11 to 14 Speed calculation means 21 to 24 Acceleration calculation means 31 to 34 Acceleration differential value calculation means 51 to 54 Gliding speed calculation means 61 to 64 Judgment command means

Claims (1)

(57) [Claims] 1. An axle rotation pulse is received as an input signal,
A brake control device that determines a sliding state of the wheel with respect to the rail by processing the signal, and controls a rise, a reduction, a holding, or a return of a braking force according to the state; Speed calculation means for calculating the axle rotation speed; acceleration calculation means for calculating the acceleration from the difference between the current value and the previous value of the axle rotation speed; acceleration from the difference between the current value and the previous value of the acceleration an acceleration differential value calculating means for calculating a differential value; and sliding speed calculation means for calculating a sliding speed is the difference between the reference speed and the axle rotation speed; and the reference velocity generating means for generating a reference speed representing the vehicle speed; At the time of start-up or holding during start-up , it is possible to determine the start of the gliding state by using three conditions where the gliding speed is a certain value or more, the acceleration is a certain value or less, and the acceleration differential value is a certain value or less. And a first determination command means for issuing a braking force reduction command.