WO2019024573A1

WO2019024573A1 - Speed-based segmented braking force control method

Info

Publication number: WO2019024573A1
Application number: PCT/CN2018/088036
Authority: WO
Inventors: 徐红星; 肖飞; 曾要争; 张潜; 鄢艳丽; 朱建安; 刘兵
Original assignee: 中车南京浦镇车辆有限公司
Priority date: 2017-07-31
Filing date: 2018-05-23
Publication date: 2019-02-07
Also published as: CN107472292A; CN107472292B

Abstract

A speed-based segmented braking force control method, the method comprising the steps of: drawing a deceleration and speed curve at a braking level of 100%; drawing deceleration and speed curves at other braking levels; collecting a speed signal; applying a braking level; and determining the deceleration and calculating and applying an electric braking force. In this solution, an electric braking capability curve is used as the basis for segmented braking force control, and by using a speed signal output by a speed sensor and the level of braking applied to a vehicle, a braking system automatically performs braking control according to a corresponding deceleration on the braking curve, such that the problems of sliding at a high speed segment and excessive wear can be effectively solved.

Description

Speed-based segmented braking force control method

Technical field

The invention relates to the field of rail vehicle brake system design, in particular to a speed-based segmented braking force control method.

Background technique

With the continuous improvement of the operation speed of domestic metro vehicles, some cities have opened intercity lines with a speed of 120km/h. However, the current vehicle braking uses the control method imposed by constant braking force. Thus, there will be the following problems:

1. Since the wheel-rail adhesion coefficient decreases with the increase of the speed, the train's wheel-rail adhesion coefficient decreases in the high-speed section. At this time, the control method with constant braking force is prone to slip.

In the domestic 120km/h subway taxi test, it is found that the number of taxis in the speed range of 95km/h to 110km/h is relatively high, and the extension of the braking distance by the high-speed train is very obvious.

3. Due to the constant power characteristics of the motor at high speed, the electric braking capability is reduced, which causes the air brake to be supplemented during high-speed braking, which increases the wear and maintenance cost of the brake pad.

Summary of the invention

The technical problem to be solved by the present invention is to solve the above-mentioned deficiencies of the prior art, and to provide a speed-based segmented braking force control method, which is characterized in that the electric braking capability curve is segmented. The basis of the braking force control, through the speed signal output by the speed sensor and the application level of the vehicle brake, the braking system automatically performs the braking control according to the corresponding deceleration on the braking curve, which can effectively solve the problem of high speed sliding and transient wear.

In order to solve the above technical problems, the technical solution adopted by the present invention is:

A speed-based segmented braking force control method includes the following steps.

Step 1. Draw the equivalent braking curve of the electric brake: firstly, the speed V is the horizontal axis, and the speed is in the range of 0-120 km/h; then the deceleration a is the vertical axis, and the electric braking constant power characteristic is drawn. The electric brake equivalent deceleration curve; the electric brake equivalent deceleration curve is drawn with 100% electric braking force; in the electric brake equivalent deceleration curve after drawing, the speed V is 0-95km/h The interval is low speed section, the train runs at the equivalent deceleration a ₁ , the speed V is in the high speed section in the interval of 95-120km/h, and the train runs at a variable deceleration, wherein the equivalent deceleration corresponding to 120km/h is a ₂ .

Step 2: Equivalent deceleration and speed curve when drawing 100% braking level: Under the same coordinate axis as step 1, use the following formula (1) to draw the equivalent deceleration and speed when 100% braking level Curve; the curve after drawing is stored in the brake system or traction system.

In the formula, a ₁ and a ₀ are constants, and a ₀ is the equivalent deceleration corresponding to 120 km/h in the speed deceleration and velocity curve when the brake is in the 100% braking level, a ₁ >a ₀ , and a ₀ It is 0.9-0.95 times that of a ₂ .

Step 3: Equivalent deceleration and speed curves when drawing other braking levels: Other braking levels include 90% braking level, 70% braking level, 50% braking level and 30% braking level Bit; under the same coordinate axis as step 1, according to the following formula (2), sequentially draw the deceleration and velocity curves corresponding to each of the other braking levels; the curve is stored in the braking system after drawing Or in the traction system;

Where k is the proportional value of the corresponding brake level.

Step 4: Speed signal acquisition: a speed sensor is arranged on the subway train, and the speed sensor is respectively connected with the signal system, the braking system and the traction system; the speed sensor collects the speed signal of the subway train in real time, and collects the speed signal. It is simultaneously transmitted to the signal system, brake system and traction system.

Step 5: Braking level application: The train control unit VCU requests the braking system and the traction system to apply braking according to the braking level according to the braking command and the current analog quantity signal issued by the controller or the signal system.

Step 6. Deceleration determination: Deceleration determination method, including the following steps.

Step 61: Select the braking level deceleration and speed curve: the braking system or the traction system applies the braking level applied according to step 5, and the system stored in steps 2 and 3 according to the principle that the proportional values in the braking level are equal. Select the required brake level deceleration and speed curve in the dynamic stage deceleration and speed curve.

Step 62: Deceleration determination: according to the speed signal acquired in step 4, selecting the deceleration value corresponding to the speed signal from the braking level deceleration and speed curve selected in step 61, that is, the deceleration required to be determined .

Step 7. Calculation and application of electric braking force: The braking system or the traction system determines the real-time deceleration of the train according to step 62, calculates the braking force required by the vehicle according to the load signal, and sends the calculated braking force to the traction system. The electric braking force request value causes the subway train to operate at the deceleration determined in step 62.

In step 7, when calculating the electric braking force: based on the braking stage deceleration and speed curve stored in steps 2 and 3, the slope of the deceleration is fitted in the high speed section of 95-120 km/h. Into a rising step curve, the step width is 0.5-1.5km / h.

In the formula (1), a ₁ = 1.074 and a ₀ = 0.88.

The speed sensor in step 4 is a three-channel sensor.

In step 4, the controller or signal system applies the brake level to the brake system, and the brake system is connected to the traction system through the interface, and the traction system sends the “electric braking force capability value” based on the bogie to the brake system. And an "electric braking state"; the braking system sends an "electric braking force request" based on the effective power bogie to the traction system; after the traction system receives the "electric braking force request" signal, applies the electrical system requested by the braking system At the same time, the traction system needs to feed back the "actual value of electric braking force" to the brake system.

The brake system will send an "electric braking force request" based on the active power bogie to the traction system via the train control network MVB.

The invention has the following beneficial effects:

1. Instead of controlling the vehicle's brake level according to the constant deceleration, the speed signal is added, and different decelerations are applied according to the change of the speed.

2. According to the available adhesion of wheel and rail, the speed is divided into low speed section of 0km/h-95km/h and high speed section of 95km/h-120km/h. The low speed section adopts constant deceleration control, and the high speed section adopts reduction and reduction. Speed control, with a speed of 95km/h as the demarcation point, achieves the efficiency of braking deceleration and the balance of wheel and rail adhesion utilization, providing full utilization of electric braking capability, reducing brake wear and post-maintenance costs.

3. The speed sources used by the signal system, the traction system and the braking system are consistent, avoiding the inconsistency of the vehicle deceleration due to the inconsistent speed of the various systems.

4. Brake deceleration control is adopted for the different braking commands in proportion to the braking level.

5. The deceleration definition in the segment braking force curve is based on the adhesion between the wheel and rail and the electric braking capability curve. The principle is that 100% use electric braking, and the high speed section braking deceleration curve is based on the electric braking constant characteristic curve. In the high speed section, the air brake is not supplemented, and the brake wear is reduced.

6. Segment braking force curve In the high-speed section, while making full use of electric braking, the real-time calculation of air braking lags behind the application and feedback of electric braking. As the speed decreases, the demand for air braking to decelerate gradually In this aspect, the high-speed section segment braking force adopts the undercut electric brake constant power characteristic curve, so that the braking deceleration demand is less than the electric braking capacity by 5-10%, ensuring that the high-speed section completely uses the electric brake for braking. .

7. In the case of electric air brake mixing, the air brake system is prevented from replenishing unnecessary air braking force when the electric braking force is sufficient to meet the braking demand.

DRAWINGS

Figure 1 shows the deceleration and velocity curves for the 100% braking level in the present invention.

Figure 2 shows the segmented braking force curves for different braking levels.

Figure 3 shows the relationship between the segment braking force curve and the electric brake constant power characteristic curve.

Fig. 4 is a block diagram showing the data interface of the segment braking force control method of the present invention.

Figure 5 shows a schematic of the rising step fit curve.

Detailed ways

The invention will now be described in further detail with reference to the drawings and specific preferred embodiments.

In the present invention, the speed is divided into a low speed section of 0-95 km/h and a high speed section of 95-120 km/h.

As shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 4, a speed-based segment braking force control method includes the following steps.

Step 1. Draw an electric brake equivalent deceleration curve.

First, the velocity V is the horizontal axis, and the speed ranges from 0 to 120 km/h. Then, with the deceleration a as the vertical axis, the electric brake equivalent of the electric brake constant power characteristic as shown in Fig. 3 is drawn. Deceleration curve.

The electric brake equivalent deceleration curve is drawn with 100% electric braking force, that is, the maximum electric braking force is adopted.

In the electric brake equivalent deceleration curve after the drawing is completed, the speed V is in the low speed section in the range of 0-95km/h, the train runs at the equivalent deceleration a ₁ , and the speed V is in the high speed zone in the interval of 95-120km/h. In the segment, the train runs at a variable deceleration, wherein the equivalent deceleration corresponding to 120 km/h is a ₂ , as shown in Fig. 3, a ₂ = 0.93.

Step 2, draw the equivalent deceleration and speed curve of the brake when the 100% brake level is drawn.

Under the same coordinate axis as in step 1, the equivalent deceleration and speed curves are plotted in the 100% braking level according to the following formula (1); the plotted curve is stored in the braking system or the traction system.

In the present invention, a ₁ is preferably 1.074, and a ₀ is preferably 0.94 times of a ₂ , that is, a ₀ =0.88, and the equivalent deceleration and velocity curves are shown in FIG. 1 when the 100% braking level after drawing is completed. .

It can be seen from Fig. 1 that the low speed section adopts the constant deceleration control, the high speed section adopts the variable deceleration control, and the braking starts from the initial speed of 120 km/h, and the deceleration gradually increases with the decrease of the speed.

The equivalent deceleration and speed curve of the 100% braking level after drawing is completed and the electric braking equivalent deceleration curve drawn in step 1 are placed in a table, as shown in Figure 3, it can be seen that at 95- In the 120km/h high-speed section, the equivalent deceleration and speed curve at the 100% braking level is below the electric vehicle equivalent deceleration curve, that is, the electric braking force retains a margin of about 10%, which embodies sufficient Use the principle of electric braking.

In addition, the deceleration curve at 95km/h is consistent with the electric brake equivalent deceleration curve point, that is, the deceleration requirement of the whole vehicle is 1.074. The curve of the deceleration from 95km/h is a straight line, and the electric system The dynamic equivalent deceleration curve (arc) starts from 95km/h, and the deceleration to 120km/h is 0.88. The guaranteed deceleration curve is below the electric brake equivalent deceleration curve. During the braking process, The braking force of the whole vehicle can be completely applied by the electric brake, avoiding the use of air brake and reducing brake shoe wear.

Step 3: Draw the equivalent braking deceleration and speed curve for other braking levels: Other braking levels include 90% braking level, 70% braking level, 50% braking level and 30% system In the same coordinate axis as in step 1, according to the following formula (2), the deceleration and speed curves corresponding to each of the other brake level positions shown in FIG. 2 are sequentially drawn; The drawn curve is stored in the brake system or traction system.

Where k is the proportional value of the corresponding brake level, and k is 90%, 70%, 50% or 30%, respectively.

As shown in Fig. 2, taking the 50% braking level applied by the train as an example, the braking deceleration in the full speed section is 50% of the deceleration corresponding to the 100% braking level.

Step 4: Speed signal acquisition: a speed sensor is arranged on the subway train, and the speed sensor signal is respectively connected with the signal system, the braking system and the traction system; the speed sensor collects the speed signal of the subway train in real time, and the speed of the acquisition is obtained. The signals are simultaneously transmitted to the signal system, the brake system and the traction system.

Further, the speed sensor described above is preferably a three-channel sensor.

The above controller or signal system preferably applies a brake level to the brake system. As shown in FIG. 4, the brake system is connected to the traction system through an interface, and the traction system sends the "electric braking force" based on the bogie to the brake system. "Capacity value" and "electric braking state"; the braking system preferably transmits an "electric braking force request" based on the effective power bogie to the traction system through the train control network MVB; the traction system receives the "electric braking force request" After the signal, the electric braking force requested by the brake system is applied; at the same time, the traction system needs to feed back the "actual value of the electric braking force" to the braking system.

The above brake system is also an air brake system.

According to the invention, the electric brake is used 100%, and the high-speed section braking deceleration curve is based on the electric brake constant power characteristic curve, and the air brake is not supplemented in the high speed section, thereby reducing the brake wear.

The above-mentioned braking system is arranged to provide protection for electric braking in the traction system to prevent power failure or circuit failure.

Step 5: Braking level application: The train control unit VCU requests the braking system and the traction system according to the braking level (current) according to the braking command issued by the controller or the signal system and the current analog signal (4-20 mA). Analog signal) applies brake.

In the present invention, it is preferable that the braking system determines the real-time deceleration in which the train is located according to step 62, and calculates the braking force required for the entire vehicle according to the load signal, and the braking system transmits the electric braking force request value to the traction system according to FIG. The electric brake will exert the electric braking force according to its own ability, and the traction system will send the actual value of the electric braking force to the braking system in real time. If the actual value of the electric braking can meet the electric braking force request value, the air brake will not be replenished. The vehicle deceleration will be braked according to the deceleration curve; if the actual value of the electric brake cannot meet the electric braking force request value, the air brake will supplement the remaining braking force, and the vehicle deceleration will still be based on the deceleration curve. brake.

In step 7, when calculating the electric braking force: based on the braking stage deceleration and speed curve stored in steps 2 and 3, the slope of the deceleration is fitted in the high speed section of 95-120 km/h. Into a rising step curve, as shown in FIG. 5, the step width is preferably 0.5-1.5 km/h.

In this way, the electric braking force can be sufficiently time-responsive and applied, and the actual deceleration curve is fitted by the rising step curve shown in FIG. In this way, the braking system calculates the braking force of the whole vehicle according to the current speed at the starting point of one step, and sends the electric braking request value and the actual value of the electric braking in sufficient time in the range of the step, and the electric brake is fully applied. At the beginning of a step, the brake system will calculate the braking force of the vehicle again according to the actual vehicle speed. This can reduce the data processing capacity of the traction and braking, because the braking speed is sampled at 32 ms. If the step width is not set, the braking force changes periodically. It will be 32ms, the braking force of the whole vehicle will always be in the state of jitter, the electric brake is not fully established, and the new electric brake demand value has changed, which is not conducive to vehicle shake and smoothness control.

It can be seen that the inventive concept is simple, simple to control, and convenient to implement. On the one hand, it reduces the need for adhesion between the high-speed section and the wheel-rail, which greatly reduces the taxiing of the train and reduces the risk of punching after the train is taxiing. On the other hand, it fully utilizes the electric braking capability to achieve the braking force in the high-speed section. The demand value does not exceed the electric brake constant power characteristic curve, and the high speed section does not supplement the air brake to reduce the wear of the brake pad. The invention can be widely used in an elevated line subway or intercity train with a speed of more than 100 km/h.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments, and various equivalent transformations may be made to the technical solutions of the present invention within the scope of the technical idea of the present invention. All fall within the scope of protection of the present invention.

Claims

A speed-based segment braking force control method, comprising: the following steps:

Step 1. Draw the equivalent deceleration curve of the electric brake: firstly, the speed V is the horizontal axis, and the speed is in the range of 0-120 km/h; then the deceleration a is the vertical axis, and the electric brake equivalent reduction is drawn. Speed curve; 100% electric braking force is used when drawing the electric braking equivalent deceleration curve; in the electric braking equivalent deceleration curve after drawing, the speed V is in the low speed section in the range of 0-95km/h, the train The equivalent deceleration a 1 is running, the speed V is in the high speed section in the interval of 95-120km/h, and the train runs on the variable deceleration curve under the electric braking constant power characteristic, wherein the equivalent deceleration corresponding to 120km/h For a 2 ;

Step 2: Draw the equivalent deceleration and speed curve of the brake when the 100% braking level is set: Under the same coordinate axis as in step 1, draw the equivalent deceleration when the 100% braking level is drawn according to the following formula (1). And the speed curve; the drawn curve is stored in the brake system or the traction system;

In the formula, a 1 and a 0 are constants, and a 0 is the equivalent deceleration corresponding to 120 km/h in the speed deceleration and velocity curve when the brake is in the 100% braking level, a 1 >a 0 , and a 0 0.9 to 0.95 times for a 2 ;

Step 3: Draw the equivalent braking deceleration and speed curve for other braking levels: Other braking levels include 90% braking level, 70% braking level, 50% braking level and 30% system In the same coordinate axis as in step 1, according to the following formula (2), the deceleration and velocity curves corresponding to each of the other braking levels are sequentially drawn; In a moving system or traction system;

Where k is the proportional value of the corresponding brake level;

Step 4: Speed signal acquisition: a speed sensor is arranged on the subway train, and the speed sensor signal is respectively connected with the signal system, the braking system and the traction system; the speed sensor collects the speed signal of the subway train in real time, and the speed of the acquisition is obtained. The signal is simultaneously transmitted to the signal system, the braking system and the traction system;

Step 5: Braking level application: The train control unit VCU requests the braking system and the traction system to apply braking according to the braking level according to the braking command and the current analog quantity signal issued by the controller or the signal system;

Step 6, deceleration determination: deceleration determination method, comprising the following steps:

Step 61: Select the braking level deceleration and speed curve: the braking system or the traction system applies the braking level applied according to step 5, and the system stored in steps 2 and 3 according to the principle that the proportional values in the braking level are equal. Select the desired brake level deceleration and speed curve in the dynamic stage deceleration and speed curve;

Step 62: Deceleration determination: according to the speed signal acquired in step 4, selecting the deceleration value corresponding to the speed signal from the braking level deceleration and speed curve selected in step 61, that is, the deceleration required to be determined ;

Step 7. Calculation and application of electric braking force: The braking system or the traction system determines the real-time deceleration of the train according to step 62, calculates the braking force required by the vehicle according to the load signal, and sends the calculated braking force to the traction system. The electric braking force request value causes the subway train to operate at the deceleration determined in step 62.
The speed-based segment braking force control method according to claim 1, wherein in the step 7, the electric braking force is calculated: based on the braking level deceleration and speed curves stored in steps 2 and 3. At a high speed section of 95120 km/h, the ramp line is fitted to an ascending step curve with a step width of 0.5-1.5 km/h.
The speed-based segment braking force control method according to claim 1, wherein in the formula (1), a 1 = 1.074 and a 0 = 0.88.
The speed-based segment braking force control method according to claim 1, wherein the speed sensor in step 4 is a three-channel sensor.
The speed-based segment braking force control method according to claim 1, wherein in step 4, the controller or the signal system applies a brake level to the brake system, and the brake system passes through the interface and the traction system. Connected, the traction system sends a "electric braking force capability value" based on the bogie and an "electric braking state" to the braking system; the braking system sends an "electric braking force request" based on the effective power bogie to the traction system; After receiving the "electric braking force request" signal, the system applies the electric braking force requested by the braking system; at the same time, the traction system needs to feed back the "electric braking force actual value" to the braking system.
The speed-based segment braking force control method according to claim 5, wherein the brake system transmits an "electric braking force request" based on the effective power bogie to the traction system via the train control network MVB.