JP6797319B2 - Brake control device for railway vehicles and brake control method for railway vehicles - Google Patents

Description

The present invention relates to a railroad vehicle brake control device and a railroad vehicle brake control method.

A mechanical braking device mounted on a railroad vehicle generates a braking force by pressing a brake shoe against a wheel or a brake pad against a disc. That is, a braking force is generated by pressing a friction material, which is a brake shoe or a brake pad, against a rotating body, which is a wheel or a disc, which rotates when a railroad vehicle travels.

The brake control device for a railroad vehicle disclosed in Patent Document 1 calculates a required braking force by conventional brake control and outputs a brake control signal to an electropneumatic conversion valve. The brake control device generates a target speed pattern from the vehicle speed and the current position of the railroad vehicle, and performs feedback control for following the speed of the railroad vehicle to the target speed at each time or point indicated by the target speed pattern.

Japanese Unexamined Patent Publication No. 2003-291797

When the brake shoe is pressed against the wheel to generate the braking force, the contact surface is mirrored when the load on the wheel represented by the product of the braking force and the peripheral speed of the wheel is equal to or less than the threshold value. The friction coefficient decreases due to the mirroring of the contact surface. On the other hand, when the load on the wheel is larger than the above threshold value, the contact surface becomes rough and the friction coefficient increases. When the friction coefficient changes, the braking force varies even when a constant pressing force is generated by a constant braking operation. Fluctuations in the coefficient of friction are not taken into account when calculating the required braking force by conventional brake control disclosed in Patent Document 1. Therefore, in the conventional brake control, the braking force varies depending on the load on the wheels.

The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress variations in braking force.

In order to achieve the above object, the brake control device for a railroad vehicle of the present invention is a brake control device that controls a mechanical brake device that generates a braking force by pressing a friction material against a rotating body that rotates when the railroad vehicle is traveling. It is provided with a command acquisition unit, a required braking force calculation unit, a generated pressing force calculation unit, a friction coefficient calculation unit, a brake pressure calculation unit, and an output unit. The command acquisition unit acquires a brake command indicating deceleration. When the command acquisition unit acquires the brake command, the required braking force calculation unit calculates the required braking force, which is the braking force required to obtain the deceleration, from the deceleration and the load of the vehicle or the bogie. The generated pressing force calculation unit calculates the generated pressing force, which is the force that presses the friction material against the rotating body. The friction coefficient calculation unit estimates the state of the contact surface between the friction material and the rotating body based on the generated pressing force, and calculates the friction coefficient according to the estimated contact surface state. The brake pressure calculation unit calculates the brake pressure from the required braking force and the friction coefficient. The output unit adjusts the pressure of the fluid supplied from the fluid source according to the brake pressure, and outputs the fluid whose pressure has been adjusted.

According to the present invention, the friction coefficient is calculated according to the state of the contact surface estimated based on the generated pressing force generated in the mechanical braking device, and the brake pressure is calculated according to the calculated friction coefficient. It is possible to suppress variations in braking force.

A block diagram showing a configuration example of a brake control device for a railway vehicle according to an embodiment of the present invention. Block diagram showing a configuration example of the brake control unit according to the embodiment Block diagram showing a configuration example of the friction coefficient calculation unit according to the embodiment A flowchart showing an example of the operation of the brake control performed by the brake control device for a railway vehicle according to the embodiment. The figure which shows the configuration example of the hardware of the brake control part which concerns on embodiment

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same or equivalent parts are designated by the same reference numerals.

FIG. 1 is a block diagram showing a configuration example of a brake control device for a railway vehicle according to an embodiment of the present invention. The rail vehicle brake control device (hereinafter referred to as a brake control device) 1 acquires a brake command and controls the mechanical brake device 4 operated by the fluid in response to the acquired brake command. In the example of the embodiment, the brake control device 1 acquires a brake command from, for example, a brake setter 2 provided in the driver's cab. The brake control device 1 adjusts the pressure of the fluid supplied by the fluid source 3, and supplies the pressure-adjusted fluid to the brake cylinder of the mechanical brake device 4 to control the brake of the railway vehicle. The fluid is, for example, air, oil, or the like. In the example of the embodiment, air is used as the fluid. The fluid source 3 is, for example, a source air tank filled with air compressed by an air compressor.

The mechanical brake device 4 generates a braking force by pressing the brake shoe against the wheel or pressing the brake pad against the disc. That is, a braking force is generated by pressing the friction material of the mechanical braking device 4, such as a brake shoe or a brake pad, against a rotating body such as a wheel or a disc that rotates during traveling of a railway vehicle. The load-bearing detector 5 detects the load of the vehicle or the trolley. The speed sensor 6 detects the peripheral speed of the wheel. The speed sensor 6 is attached to, for example, the axles of the front and rear bogies in each rolling stock of a railroad vehicle. That is, four speed sensors 6 are attached to each vehicle. The speed sensor 6 detects the peripheral speed of the wheel from the rotation speed of the axle.

In FIG. 1, the fluid source 3 and each part of the brake control device 1 and each part of the brake control device 1 and the mechanical brake device 4 are all connected by air pipes, which are connected by a solid line. In FIG. 1, the dotted arrow indicates an electric signal, and all parts of the brake control device 1 and between the brake setter 2 and each part of the brake control device 1 connected by the dotted arrow are connected by an electric circuit. Will be done.

The brake control device 1 adjusts the pressure of the fluid supplied by the fluid source 3 according to the brake control unit 11 that outputs a control signal instructing the brake pressure based on the brake command, and the pressure is adjusted. The output unit 12 for outputting the fluid and the pressure sensor 15 for detecting the pressure of the fluid output by the output unit 12 are provided. The output unit 12 is supplied from the electro-pneumatic conversion valve 13 that adjusts the pressure of the fluid supplied by the fluid source 3 according to the control signal and outputs the output, and is supplied from the fluid source according to the output of the electro-pneumatic conversion valve 13. It has a relay valve 14 that adjusts the pressure of the fluid and outputs it to the mechanical brake device 4.

The brake control unit 11 estimates the state of the contact surface between the friction material and the rotating body based on the generated pressing force generated by the mechanical brake device 4. The brake control unit 11 calculates the friction coefficient according to the estimated state of the contact surface, and calculates the brake pressure based on the calculated friction coefficient. The brake control unit 11 performs feedback control according to the detected value of the pressure sensor 15. By calculating the brake pressure based on the friction coefficient calculated according to the state of the contact surface, it is possible to suppress the variation in the braking force actually generated by the mechanical braking device 4. By providing the electropneumatic conversion valve 13, the control signal, which is an electric signal, can be converted into an pneumatic signal. The relay valve 14 is provided to improve the responsiveness of the mechanical brake device 4. The pressure sensor 15 detects the pressure of the fluid output from the relay valve 14 and sends the detected value as an electric signal to the brake control unit 11. The detected value of the pressure sensor 15 can be regarded as the pressure of the brake cylinder of the mechanical brake device 4.

FIG. 2 is a block diagram showing a configuration example of the brake control unit according to the embodiment. The brake control unit 11 determines the command acquisition unit 21 that acquires the brake command, the required brake force calculation unit 22 that calculates the required braking force that is the braking force required to obtain the deceleration indicated by the brake command, and the peripheral speed of the wheels. The speed acquisition unit 23 to acquire, the generated pressing force calculating unit 24 that calculates the generated pressing force that is the force that presses the friction material against the rotating body, the state of the contact surface is estimated, and the friction coefficient is calculated according to the estimated state of the contact surface. A friction coefficient calculation unit 25 for calculating and a brake pressure calculation unit 26 for calculating a brake pressure are provided.

The command acquisition unit 21 acquires a brake command indicating deceleration from the brake setter 2. The command acquisition unit 21 may acquire a brake command from an ATC (Automatic Train Control: automatic train control device), an ATO (Automatic Train Operation: automatic train operation device), or the like.

The required braking force calculation unit 22 calculates the required braking force, which is the braking force required to obtain the deceleration indicated by the brake command. The required braking force calculation unit 22 sends the calculated required braking force to the brake pressure calculation unit 26. The required braking force calculation unit 22 may calculate the required braking force for each vehicle, or may calculate the required braking force for each trolley. The required braking force calculation unit 22 calculates the required braking force for each vehicle or trolley based on the brake command and the load of the vehicle or trolley. Since the load is the product of mass and gravitational acceleration, when the load is detected in the unit where the load detection value matches the mass in the load-bearing detector 5, the required brake is calculated by the product of the deceleration and the load detection value. The force can be calculated. For example, when the deceleration indicated by the brake command is α and the load of each vehicle detected by the load-bearing detector 5 is W1, W2, ..., Wk, the required braking force of each vehicle is α / W1. , Α ・ W2, ···, α ・ Wk. As the load of the vehicle or trolley not yet provided with the load-bearing detector 5, the load of another vehicle or trolley provided with the load-bearing detector 5 may be used.

The speed acquisition unit 23 acquires the peripheral speed of the wheel from, for example, the speed sensor 6 attached to the axle. The speed acquisition unit 23 may acquire the peripheral speed of the wheels from, for example, a train information management system, ATC, or the like.

The generated pressing force calculation unit 24 calculates the generated pressing force, which is a force for pressing the friction material against the rotating body. The generated pressing force calculation unit 24 calculates the generated pressing force by multiplying the BC pressure detected by the pressure sensor 15 by the pipe diameter of the brake cylinder. Alternatively, the generated pressing force calculation unit 24 may calculate the generated pressing force based on the required braking force calculation unit 22.

The friction coefficient calculation unit 25 estimates the state of the contact surface based on the generated pressing force, and calculates the friction coefficient according to the estimated state of the contact surface. The friction coefficient calculation unit 25 is updated based on the generated pressing force, holds a state index indicating the state of the contact surface, and calculates the friction coefficient according to the state index. Alternatively, the friction coefficient calculation unit 25 may calculate the friction coefficient based on a table that associates the generated pressing force with the state of the contact surface and a table that associates the state of the contact surface with the friction coefficient.

The brake pressure calculation unit 26 calculates the brake pressure from the required braking force calculated by the required braking force calculation unit 22 and the friction coefficient calculated by the friction coefficient calculation unit 25. The brake pressure calculation unit 26 calculates the target value B of the brake pressure as represented by the following equation (1). In the following equation (1), F is the required braking force, k is a constant, and μ is the friction coefficient. The brake pressure calculation unit 26 performs feedback control based on the target value B of the brake pressure and the detection value of the pressure sensor 15, and calculates the control amount of the brake pressure. The brake pressure calculation unit 26 outputs an electric signal indicating a control amount to the electropneumatic conversion valve 13.
B = F / (k · μ) ・ ・ ・ (1)

The electropneumatic conversion valve 13 shown in FIG. 1 includes, for example, an AV solenoid valve which is an electromagnetic valve for supplying air and an RV solenoid valve which is an electromagnetic valve for discharging air. The electropneumatic conversion valve 13 adjusts the pressure of the fluid supplied by the fluid source 3 according to an electric signal indicating a control amount of the brake pressure output by the brake control unit 11, and outputs the pressure to the relay valve 14. As described above, the relay valve 14 adjusts the pressure of the fluid supplied from the fluid source 3 according to the output of the electropneumatic conversion valve 13 and outputs the pressure to the mechanical brake device 4. As a result, the mechanical brake device 4 operates.

As expressed by the above equation (1), as the friction coefficient μ increases, the target value B of the brake pressure decreases. On the other hand, as the friction coefficient μ becomes smaller, the target value B of the brake pressure becomes larger. The braking force generated by the mechanical braking device 4 is proportional to the product of the friction coefficient μ and the braking pressure of the brake cylinder. As described above, since the target value B of the brake pressure changes in inverse proportion to the friction coefficient μ, it is possible to suppress the variation in the braking force caused by the mechanical braking device 4 even if the friction coefficient changes. That is, since the brake pressure is calculated based on the friction coefficient calculated according to the state of the contact surface, even if the friction coefficient fluctuates due to the change in the state of the contact surface, the variation in the braking force is suppressed. It is possible.

FIG. 3 is a block diagram showing a configuration example of the friction coefficient calculation unit according to the embodiment. The friction coefficient calculation unit 25 has a storage unit 34 in which the state index is stored. The friction coefficient calculation unit 25 further calculates a load amount represented by a product of the generated pressing force and the peripheral speed, a load calculation unit 31, calculates a state index based on the load amount, and stores the state index in the storage unit 34. It has an index update unit 32 that updates the index, and an index conversion unit 33 that calculates a friction coefficient according to the state index stored in the storage unit 34. The state index W indicates the state of the contact surface. The state index W is associated with the friction coefficient μ, and the friction coefficient calculation unit 25 can calculate the friction coefficient μ from the state index W. The association between the state index W and the friction coefficient μ is arbitrary. In the example of the embodiment, the state index W and the friction coefficient μ are associated with each other in a positive correlation. That is, as the state index W increases, the friction coefficient μ increases. With respect to the initial value W ₀ of the state index W, the initial value μ ₀ of the friction coefficient μ is determined based on the material of the friction material and the rotating body. As will be described later, the friction coefficient calculation unit 25 repeatedly calculates the state index W based on the load amount from the state of the state index W = W ₀ , and associates it with the state index W stored in the storage unit 34. Calculate the obtained μ.

When the peripheral speed acquired by the speed acquisition unit 23 is equal to or higher than the first threshold value, the load calculation unit 31 calculates the load amount Q as represented by the following equation (2). In the following equation (2), F _bi is the generated pressing force, R _i is the radius of the wheel, and ω _i is the angular velocity of the axle. Peripheral speed of the wheel is represented by _{R i} · _{ω i.} The load calculation unit 31 determines whether or not the railway vehicle is traveling based on whether or not the peripheral speed is equal to or higher than the first threshold value. The first threshold is, for example, 2 km / h.
Q = F _bi・ R _i・ ω _i・ ・ ・ (2)

The generated pressing force F _bi is represented by the following equation (3). In the following equation (3), P _bc is the detected value of the pressure sensor 15, and S is the pipe diameter of the brake cylinder. The generated pressing force calculation unit 24 may calculate the generated pressing force F _bi by using the target value B of the brake pressure represented by the above equation (1) as the P _bc of the following equation (3).
F _bi = P _bc · S ... (3)

The index update unit 32 calculates the state index W based on the load amount Q. For example, when the load amount Q is equal to or greater than the second threshold value, the index update unit 32 calculates the value obtained by multiplying the load amount Q by the first coefficient A as the added value ΔW, as represented by the following equation (4). To do. When the load amount Q is less than the second threshold value, the exponential update unit 32 is a value obtained by multiplying the load amount Q by the second coefficient B having a different sign from the first coefficient A, as represented by the following equation (5). Is calculated as the added value ΔW. For example, A> 0 and B <0. As represented by the following equation (6), the index update unit 32 is a value obtained by multiplying the state index W by a third coefficient σ, which is a positive number of 1 or less, and adding an addition value ΔW, and is a state index. Update W. For example, σ is a positive number less than 1. By setting σ to a positive number less than 1, the state index W decreases according to σ when the brake is not applied and Q = 0. Thereby, for example, it is possible to calculate the brake pressure in consideration of the decrease in the friction coefficient μ due to the adhesion of fallen leaves, dust, etc. to the wheels during traveling. The second threshold value, the first coefficient A, the second coefficient B, and the third coefficient σ can be determined according to the material of the friction material and the rotating body.
ΔW = A · Q ・ ・ ・ (4)
ΔW = B · Q ・ ・ ・ (5)
W = σW + ΔW ・ ・ ・ (6)

The index update unit 32 repeats the calculation of the state index W as described above while the command acquisition unit 21 has acquired the brake command, and at the timing when the command acquisition unit 21 no longer acquires the brake command, the above-mentioned index update unit 32 described above. With the state index W calculated as described above, the state index W stored in the storage unit 34 is updated. As a result, it is possible to prevent the control system from becoming unstable due to fluctuations in the friction coefficient μ during the braking period.

The exponential conversion unit 33 calculates the friction coefficient μ according to the state index W stored in the storage unit 34. The friction coefficient μ may be defined as a function with the state index W as an argument, or a table for associating the friction coefficient μ with the state index W may be defined. The association between the friction coefficient μ and the state index W can be determined according to a test run, a simulation, or the like of a railway vehicle. When the index update unit 32 updates the state index W at the end of the braking period, the index conversion unit 33 calculates the friction coefficient μ according to the state index W updated at the end of the immediately preceding braking period. That is, the brake control unit 11 calculates the brake pressure according to the state of the contact surface changed by the brake control during the braking period so far.

FIG. 4 is a flowchart showing an example of a brake control operation performed by the railroad vehicle brake control device according to the embodiment. While the command acquisition unit 21 has not acquired the brake command (step S11; N), the process of step S11 is repeated. When the command acquisition unit 21 acquires the brake command (step S11; Y), the index conversion unit 33 of the friction coefficient calculation unit 25 calculates the friction coefficient μ from the state index W held by the storage unit 34. (Step S12). The generated pressing force calculation unit 24 calculates the generated pressing force (step S13). The index updating unit 32 of the friction coefficient calculating unit 25 calculates the state index W based on the load amount Q (step S14). The required braking force calculation unit 22 calculates the required braking force from the deceleration indicated by the brake command and the load of the vehicle or the carriage (step S15). The brake pressure calculation unit 26 calculates the brake pressure from the required braking force calculated by the required braking force calculation unit 22 and the friction coefficient calculated by the friction coefficient calculation unit 25 (step S16). The output unit adjusts the pressure of the fluid supplied by the fluid source 3 according to the brake pressure calculated by the brake pressure calculation unit 26, and outputs the adjusted fluid to the mechanical brake device 4, thereby mechanically braking. The device 4 is controlled (step S17).

While the brake command is continuously acquired (step S18; Y), the process returns to step S13 and the above process is repeated. When the brake command is no longer acquired (step S18; N), the index update unit 32 updates the state index W stored in the storage unit 34 with the state index W calculated by repeating the process of step S14. (Step S19). When the process of step S19 is completed, the brake control process is completed.

As described above, according to the brake control device 1 according to the present embodiment, the friction coefficient is calculated according to the state of the contact surface estimated based on the generated pressing force, and the brake pressure is calculated according to the calculated friction coefficient. By calculating, it is possible to suppress the variation in braking force.

FIG. 5 is a diagram showing a configuration example of the hardware of the brake control unit according to the embodiment. The brake control unit 11 includes a processor 41, a memory 42, and an interface 43 as a hardware configuration for controlling each unit. Each function of these devices is realized by the processor 41 executing a program stored in the memory 42. The interface 43 is for connecting each device and establishing communication, and may be composed of a plurality of types of interfaces as needed. Although FIG. 5 shows an example in which the processor 41 and the memory 42 are each configured by one, the plurality of processors 41 and the plurality of memories 42 may cooperate to execute each function.

In addition, the above-mentioned hardware configuration and flowchart are examples, and can be arbitrarily changed and modified.

The central part of the control process including the processor 41, the memory 42, and the interface 43 can be realized by using a normal computer system without using a dedicated system. For example, a computer program for performing the above operations can be a computer-readable recording medium (flexible disk, CD-ROM (Compact Disc-Read Only Memory), DVD-ROM (Digital Versatile Disc-Read Only Memory), etc. ), And by installing the computer program in the computer, the brake control unit 11 that executes the above-mentioned processing may be configured. Further, the brake control unit 11 may be configured by storing the computer program in a storage device of the server device on the communication network and downloading it by a normal computer system.

Further, when the function of the brake control unit 11 is realized by sharing the OS (Operating System) and the application program, or by coordinating the OS and the application program, only the application program part is stored as a recording medium or storage. It may be stored in the device.

It is also possible to superimpose a computer program on a carrier wave and distribute it via a communication network. For example, the computer program may be posted on a bulletin board system (BBS: Bulletin Board System) on the communication network, and the computer program may be distributed via the communication network. Then, by starting this computer program and executing it in the same manner as other application programs under the control of the OS, the above-mentioned processing may be executed.

The embodiment of the present invention is not limited to the above-described embodiment. The state index W and the coefficient of friction μ may be associated with each other in a negative correlation.

The present invention allows for various embodiments and modifications without departing from the broad spirit and scope of the present invention. Moreover, the above-described embodiment is for explaining the present invention, and does not limit the scope of the present invention. That is, the scope of the present invention is indicated by the scope of claims, not by the embodiment. Then, various modifications made within the scope of the claims and the equivalent meaning of the invention are considered to be within the scope of the present invention.

1 Brake control device, 2 Brake setter, 3 Fluid source, 4 Mechanical brake device, 5 Response load detector, 6 Speed sensor, 11 Brake control unit, 12 Output unit, 13 Electro-pneumatic conversion valve, 14 Relay valve, 15 Pressure Sensor, 21 Command acquisition unit, 22 Required braking force calculation unit, 23 Speed acquisition unit, 24 Generated push pressure calculation unit, 25 Friction coefficient calculation unit, 26 Brake pressure calculation unit, 31 Load calculation unit, 32 Index update unit, 33 Index Converter, 34 storage, 41 processor, 42 memory, 43 interfaces.

Claims (9)

A brake control device that controls a mechanical brake device that generates braking force by pressing a friction material against a rotating body that rotates when a railroad vehicle is running.
A command acquisition unit that acquires a brake command indicating deceleration,
When the command acquisition unit acquires the brake command, the required braking force calculation unit that calculates the required braking force, which is the braking force required to obtain the deceleration, from the deceleration and the load of the vehicle or the trolley. ,
A generated pressing force calculation unit that calculates a generated pressing force that is a force that presses the friction material against the rotating body,
A friction coefficient calculation unit that estimates the state of the contact surface between the friction material and the rotating body based on the generated pressing force and calculates the friction coefficient according to the estimated state of the contact surface.
A brake pressure calculation unit that calculates the brake pressure from the required braking force and the friction coefficient,
An output unit that adjusts the pressure of the fluid supplied from the fluid source according to the brake pressure and outputs the adjusted fluid.
Brake control device for railroad vehicles. The friction coefficient calculation unit is updated based on the generated pressing force, holds a state index indicating the state of the contact surface, and calculates the friction coefficient according to the state index.
The brake control device for a railway vehicle according to claim 1. A speed acquisition unit for acquiring the peripheral speed of the wheels of the railway vehicle is further provided.
The friction coefficient calculation unit
A storage unit in which the state index is stored and
When the peripheral speed is equal to or higher than the first threshold value, a load calculation unit that calculates a load amount represented by a product of the generated pressing force and the peripheral speed,
An index update unit that calculates the state index based on the load amount and updates the state index stored in the storage unit,
It has an exponential conversion unit that calculates the friction coefficient according to the state index stored in the storage unit.
The brake control device for a railway vehicle according to claim 2. When the load amount is equal to or greater than the second threshold value, the index update unit calculates a value obtained by multiplying the load amount by the first coefficient as an additional value, and when the load amount is less than the second threshold value, the index update unit calculates the value. The value obtained by multiplying the load amount by the second coefficient having a sign different from that of the first coefficient is calculated as the added value, and the added value is added to the value obtained by multiplying the state index by the third coefficient which is a positive number of 1 or less. Then, the state index is calculated.
The brake control device for a railway vehicle according to claim 3. The third coefficient is a value less than 1.
The brake control device for a railway vehicle according to claim 4. The index update unit repeats the calculation of the state index based on the load amount while the command acquisition unit acquires the brake command, and at the timing when the command acquisition unit stops acquiring the brake command. Update the state index,
The brake control device for a railway vehicle according to any one of claims 3 to 5. A pressure sensor for detecting a BC pressure indicating the pressure of the brake cylinder included in the mechanical brake device is further provided.
The generated pressing force calculation unit calculates the generated pressing force by multiplying the BC pressure detected by the pressure sensor by the pipe diameter of the brake cylinder.
The brake control device for a railway vehicle according to any one of claims 1 to 6. The generated pressing force calculation unit calculates the generated pressing force based on the required braking force calculated by the required braking force calculation unit.
The brake control device for a railway vehicle according to any one of claims 1 to 6. This is a brake control method for railway vehicles performed by a brake control device that controls a mechanical brake device that generates braking force by pressing a friction material against a rotating body that rotates when the railway vehicle is running.
When a brake command indicating deceleration is obtained, the required braking force, which is the braking force required to obtain the deceleration, is calculated from the deceleration and the load of the vehicle or trolley.
The generated pressing force, which is the force that presses the friction material against the rotating body, is calculated.
Based on the generated pressing force, the state of the contact surface between the friction material and the rotating body is estimated, and the friction coefficient is calculated according to the estimated state of the contact surface.
The brake pressure is calculated from the required braking force and the friction coefficient.
The pressure of the fluid supplied from the fluid source is adjusted according to the brake pressure, and the pressure-adjusted fluid is output.
Brake control method for railway vehicles.

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