The present invention generally pertains to a novel wheel slide protection device to
be applied in the braking system of high speed railway trains; wherein said wheel
slide protection device (hereinafter referred as "WSPD") is particularly provisioned for
monitoring the speed of every individual axle of railway coach(s), preferably in real
time, and also for controlling the brake force on the brake-disc.
Wheel slide protection device (WSPD) is designed to avoid sliding of wheels during
braking actions and during change in wheel adhesion by corresponding reductions of
air pressure in brake cylinders. Due to slide, longer braking distances and higher
longitudinal train forces occur, potentially affecting the train safety and the
passengers comfort.
The field of present invention herein proposes an advanced WSPD to detect wheel
slide using a customized control mechanism involving a new algorithm, mainly to
achieve a higher level of performance than current systems.
Inventiveness involved in the present invention generally characterized in its
following advantageous structural, constructional and functional features:
• It is an anti-skid system which improves the stopping distance on tracks contaminated with leaf, dirt, oil, water, ice and snow.
• Said WSPD of the present invention eliminates flat-spot and blown wheel during aggressive stopping on dry or contaminated tracks.
• Increases Passenger comfort
• Decreases Maintenance cost
• Antiskid system provides a maximum braking efficiency under all track conditions.

BACKGROUND OF THE PRESENT INVENTION AND PRIOR ARTS:
In railroad vehicles, provision of wheel slide protection is generally used to detect and prevent wheel-slide during braking. It is particularly important in slippery rail conditions.
Few prior arts available in public domain, which relate to wheel slide protection in vehicles.
US patent 4456309A relates to a wheel slide protection system for a vehicle, such as a car or motor cycle, has a modulator valve controlling the supply of pressure fluid to a wheel brake sensing device for sensing an incipient wheel slide condition of the braked wheel and providing a signal to cause the valve to apply a slide-corrective modification to the braking force, and a pump supplying the modulator valve and incorporated in an axle assembly adapted to carry the wheel to be braked. A fluid reservoir and the modulator valve may additionally be incorporated in the axle assembly.
Another US patent US4941099A relates to An electronic slip control system for a multiple-truck railway vehicle comprising, a standard slip control logic means responsive to axle speed and rate signals to produce a multi-bit binary number word, a primary slip control word formation means for converting the multi-bit binary number word to a hexadecimal number word which is conveyed to a primary slip control table means, said primary slip control table means conveys the hexadecimal number word to a table output selection means, a synchronous slip control logic means responsive to the axle speed and rate signals to produce a multi-bit binary word, a synchronous slip control word formation means for converting the multi-bit binary number word to a hexadecimal number word which is conveyed to a synchronous slip control table means, said synchronous slip control table means

conveys the hexadecimal number word to said table output selection means which is connected to intermediate circuit means, and said intermediate circuit means causes an appropriate control signal to be conveyed to a brake valve for preventing wheel slip.
Similarly, another US patent no. US6629709B1 relates to an apparatus for enhancing wheel/rail adhesion for a railway vehicle, the apparatus comprising means to determine a value of the adhesion by monitoring operation of the braking system when the brakes are applied, and means for applying adhesion-enhancing particles to the wheel/rail interface, at a rate which is adjusted in accordance with the value of the adhesion so determined in at least one of the following ways:(a) the vehicle incorporates an accelerometer, and the adhesion-determining means comprises means to compare the deceleration measured by the accelerometer to the deceleration demanded by the driver, and to determine a value of the adhesion from any discrepancy between those values of deceleration; and (b) the vehicle incorporates awheel slide protection system that modulates the pressure in a brake cylinder in response to detection of wheel slit, and the adhesion-determining means determines the adhesion from a determination of the pressure supplied to the brake cylinder.
Though the wheel slide protection systems for railway wagons are conventionally known and are in used, none of them is provisioned with same or similar structural and functional aspects towards effectively addressing the issues of monitoring the speed of every individual axle of railway coach(s), preferably in real time, and also for controlling the brake force on the brake-disc. None of the prior arts comprises same/similar the advantageous and characterizing features associated with the said WSPD of the present invention, such as:

1. Unique circuit of the said WSPD;
2. Exhaustive fault diagnostic mechanism for failures detection;
3. Insertion of cards in wrong slots not possible- Polarized cards;
4. Overvoltage and under voltage shutdown beyond ±30% of nominal voltage working zone; and
5. Speed processing through redundant Analog and Digital channels.
OBJECT OF THE PRESENT INVENTION:
Prime object of the present invention is to remove the drawbacks of prior known
similar wheel slide protection devices.
Other prime object of the present invention is to provide a novel Wheel Slide
Protection Device (WSPD) to be applied in the braking system of high speed railway
trains; wherein said WSPD is particularly provisioned for monitoring the speed of
every individual axel of railway wagon as well as for controlling the brake force on the
brake-disc.
Another prime object of the invention is to provide a novel Wheel slide protection
device (WSPD), designed to avoid sliding of wheels during braking actions due to
change in wheel adhesion by corresponding reductions of air pressure in brake
cylinders.
Other object of the invention is to provide an advanced WSPD to detect wheel slide
using a customized control mechanism involving a new algorithm, mainly to achieve
a higher level of performance than current systems.
Another object of the present invention is to provide such a WSPD to be used in the
braking system of high speed railway trains; wherein said WSPD is mainly consisting
of a control unit, four speed sensors, four phonic wheels and four dump valves.

Another object of the present invention is to provide such a WSPD wherein said four speed sensors and phonic wheels are provisioned for monitoring the speed of every individual axle of passenger coach/wagon and said four dump valves are provisioned for controlling the brake force on the disc to prevent the wheel and axle assembly from locking and uncontrolled sliding due to low adhesion.
Another object of the present invention is to provide the most preferred embodiment of the said WSPD, generally characterized in its following advantageous structural, constructional and functional features:
• It is an anti-skid system which improves the stopping distance on tracks contaminated with leaf, dirt, oil, water, ice and snow.
• Said WSPD of the present invention eliminates flat-spot and blown wheel during aggressive stopping on dry or contaminated tracks.
• Increases Passenger comfort
• Decreases Maintenance cost
• Antiskid system provides a maximum braking efficiency under all track conditions.
SUMMARY OF THE PRESENT INVENTION:
The invention pertains generally to a novel Wheel Slide Protection System (hereinafter referred as "protection system"), particularly provisioned for monitoring the speed of every individual axel of railway wagon as well as for controlling the brake force on the brake-disc. Said protection system mainly comprises of a microprocessor based control unit, multiple speed sensors, four phonic wheels and four dump valves. Multiple speed sensors, mainly four in number, of the said protection system are used for monitoring the speed of every individual axle of passenger coach/wagon. Four dump valves of said protection system are used for

controlling the brake force on the disc to prevent the wheel and axle assembly from locking and uncontrolled sliding due to low adhesion.
Major advantages associated with the most preferred embodiment of said WSPD of the present invention (as also depicted in Figures 3 and 4) are as under:
• It is an anti-skid system which improves the stopping distance on tracks contaminated with leaf, dirt, oil, water, ice and snow.
• Wheel Slide Protection System eliminates flat-spot and blown wheel during aggressive stopping on dry or contaminated tracks.
• Increases Passenger comfort
• Decreases Maintenance cost
• Antiskid system provides a maximum braking efficiency under all track conditions.
Short description of the Drawings:
Figure 1: Representation of the subject matter invention of prior patent US4941099,
taken from its complete specification;
Figure 2: Representation of the subject matter invention of prior patent US6629709,
taken from its complete specification;
Figure 3: It is the complete schematic representation of the block diagram of the
circuitry and the components of the Wheel Slide Protection Device (WSPD) of the
present invention.
Figure 4: It is the schematic representation of the Block Diagram of the
Microcontroller and the control unit, as the essential component of the said Wheel
Slide Protection Device (WSPD) of the present invention.

DESCRIPTION OF RELATED ART:
The assembly of said WSPD, as depicted in the block diagram of Figure 3, including the control module (1) of Figure 4 as its essential component therein, continuously monitors the rotational speed of axles on the passenger coach/wagon, and responds whenever it detects a significant difference of speed on any axle.
During the course of brake application, there are possibilities of skidding/sliding/locking of individual axle. These situations are likely to cause damage to the wheels with increased braking distance. WSPD is used to utilize the available adhesion between rail and wheel.
Speed sensors (2) are the integral part of the system which detects the rotational speed of each axle & sends signal to the processor unit as the microprocessor based Control Unit (1). Said processor unit (1) evaluates the received signal from speed sensor (2) of the vehicle & generates signals enabling the dump valve (4) to control the brake cylinder pressure in case of any locking/skidding.
The brake cylinder force is instantaneously and proportionately controlled by the dump valve (4) with respect to the available wheel to rail adhesion by the WSP.
The WSPD of the invention includes following major components in its circuitry towards achieving the wheel side protection and effective control over the whole process therein, particularly in real time:
• Speed Sensor (2).
• Phonic wheel (3).
• Microprocessor based Control unit (1).
• Dump valves (4).
• Pressure switch (5).

Speed Sensor (2):
The speed sensors (2) are fixed on one end of the axle box cover with the help of
two bolts. The sensor probe is fitted with a nominal gap to the phonic wheels and can
be adjusted as required with the help of shims. The sensor is non-contact type for
counting the axle RPM. The main function of speed sensor (2) is to pick up the
signals with the rotation of phonic wheel (3) mounted on axle end & convey to
microprocessor.
Phonic wheel (3):
The phonic wheel (3) is installed on one end of each axle on the axle box cover. The
phonic wheel (3) is a toothed wheel (gear type). The purpose of this toothed wheel is
to alter the internal inductance of the adjacent sensor (2) which generates pulse
signal during axle rotation.
Microprocessor based Control unit (1):
Microprocessor is the heart of the WSP system. The signals generated by the
rotation of phonic wheel (3) are captured by the speed sensor (2) and send to the
microprocessor which evaluates the vehicle speed. During brake application, it
continuously monitors & bridges the sharp drop of speed of a particular axle enabling
the dump valve to control/adjust the brake cylinder pressure. Watch dogging, Fault
diagnostics, Data down loading are the major functions of WSPD Controller (1). Fault
codes are stored in its memory with time stamp.
Main Electronics Boards for WSPD:
The assembly of most preferred embodiment of the said WSPD of present invention,
as also depicted in the block diagram of Figure 4 hereinbelow, comprises following
components in its Main Electronics Boards:
• Power Filter Card (6)
• Power Supply Card (7)

• CPU Card (8)
• Relay Sensor Card (9)
• 10 Card (10) with Keypad and LCD
• Interface card (11)
• COM card (13)
> Filter Card (6)
In Filter Card Surge, transient and reverse voltage protection circuits are implemented. It feeds clean power to power supply card
> Power Supply Card (7)
In Power Supply Card two DC-DC converter modules are used. One module converts 110 VDC to 24 VDC and other convert 110 VDC to 5 VDC with adequate current rating. These two modules give power to all other cards.
> CPU Card (8)
CPU Card is the heart of the system it takes care of controlling the entire system. It checks all the faults and saves faults on its memory.
> Relay Sensor Card (9)
Driving circuit of relay and sensor is placed in Relay Sensor Card. It also has sensor and driver protection circuit
> IO Card (10) with Keypad and LCD
Key-pad, LCD driving circuit and external input and output circuit is placed in IO CARD.
> Interface card (11)
All the external wires for speed sensor and Dump valves are terminated in Interface card with Surge and transient.

> COM card (12)
Third party communication circuit for CAN and RS485 is placed in COM Card
> Dump valve/Anti-skid valve (4):
Dump valve (4) is provided for each axle of the Coach/ Wagon. It consist of a special type of solenoid valve which connects the air pressure line to brake cylinder. The dump valves (4) allow to deplete the air available in brake cylinder line during brake application when slide condition is detected by WSPD microprocessor.
> Pressure switch (5):
Pressure switch (5) is provided on brake control panel. The purpose of pressure switch (5) is to activate the WSPD when the pressure reaches 1.3 to 1.8 bars.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined.

WE CLAIM

1.Wheel slide protection device (WSPD), comprises an assembly of major components of said WSPD, namely Microprocessor based Control module (WSP Unit) (1), plurality of Speed Sensors (2); Phonic wheels (3); Dump valves (4) and Pressure switch (5); wherein said WSPD is characterized in its application in the braking system of high speed railway trains and also in monitoring the speed of every individual axel of railway wagon in real time as well as for controlling the brake force on the brake-disc.
2. Wheel Slide Protection Device (WSPD), as claimed in claim 1, wherein the preferred embodiment of said WSPD comprises a Microprocessor based Control module (WSP Unit) (1), four speed sensors (2), four phonic wheels (3), four dump valves (4) and pressure switch (5); wherein the pressure switch (5), provided on brake control panel, activate the WSPD when the pressure reaches 1.3 to 1.8 bars.
3. Wheel slide protection device (WSPD), as claimed in claim 1 or 2, wherein said WSPD is provisioned to detect wheel slide, preferably in real time, using a customized control mechanism involving a new algorithm, wherein said WSPD is characterized in avoiding sliding of wheels during braking actions due to change in wheel adhesion by corresponding reductions of air pressure in brake cylinders.
4. Wheel slide protection device (WSPD), as claimed in any of the claims 1 to 4, wherein said plurality of speed sensors (2) and phonic wheels (3) are provisioned for monitoring the speed of every individual axle of passenger coach/wagon and said four dump valves (4) are provisioned for controlling the brake force on the disc to prevent the wheel and axle assembly from locking and uncontrolled sliding due to low adhesion.

5. Wheel slide protection device (WSPD), as claimed in claim 1, wherein non-contact type speed sensors (2), for counting the axle RPM, are fixed on one end of the axle box cover with the help of two bolts; and the sensor probe is fitted with a nominal gap to the phonic wheels and can be adjusted as required with the help of shims; wherein said speed sensor (2) is characterized in its function towards picking-up the signals with the rotation of phonic wheel (3) mounted on axle end & conveying said signals to microprocessor.
6. Wheel slide protection device (WSPD), as claimed in claim 1, wherein the phonic wheel (3), installed on one end of each axle on the axle box cover, is provisioned to alter the internal inductance of the adjacent speed sensor (2) generating pulse signals during axle rotation.
7. Wheel slide protection device (WSPD), as claimed in claim 1, wherein the Microprocessor based Control module (WSP Unit) (1), is characterized in at least one of the followings:

• the signals generated by the rotation of phonic wheel (3) are captured by the speed sensor (2) and send to the microprocessor which evaluates the vehicle speed;
• During brake application, said microprocessor continuously monitors & bridges the sharp drop of speed of a particular axle enabling the dump valve (4) to control/adjust the brake cylinder pressure;
• conducting Watch dogging;
• conducting Fault diagnostics;
• conducting data down loading; and
• storing Fault codes in its memory with time stamp.

8. Wheel slide protection device (WSPD), as claimed in claiml, wherein Dump valve/Anti-skid valve (4), consisting of a special type of solenoid valve which connects the air pressure line to brake cylinder, is provided for each axle of the Coach/Wagon; wherein said dump valves (4) allow to deplete the air available in brake cylinder line during brake application when slide condition is detected by said Microprocessor based Control module (WSP Unit) (1).
9. Wheel slide protection device (WSPD), as claimed in claiml, wherein said WSPD comprises the Microprocessor based Control module (WSP Unit) (1), wherein the major components in its Main Electronics Boards are:

• Power Filter Card (6):- which is implemented with Surge, transient and reverse voltage protection circuits; towards feeding clean power to power supply card (7);
• Power Supply Card (7):- which comprises two DC-DC converter modules for supplying power to all other cards of the WSP unit, wherein one module converts 110 VDC to 24 VDC and other convert 110 VDC to 5 VDC with adequate current rating;
• CPU Card (8):- which is provisioned for controlling the entire system, checking all the faults and saving faults on its memory;
• Relay Sensor Card (9):- which is driving circuit of relay and sensor is placed in Relay Sensor Card (9); wherein it also has sensor and driver protection circuit;
• IO Card (10) with Keypad and LCD:- wherein Key-pad, LCD driving
circuit and external input and output circuit is placed in IO Card (10);

• Interface card (11):- wherein all the external wires for speed sensor (2) and Dump valves (4) are terminated in Interface card (11) with Surge and transient; and
• COM Card (12):- wherein the third party communication circuit for CAN and RS485 is placed in the COM Card (12).
10. Wheel slide protection device (WSPD), as claimed in any of the claims 1 to 9, wherein the most preferred embodiment of the said WSPD is generally characterized in at least one of its following advantageous structural, constructional and functional features:
• It is an anti-skid system which improves the stopping distance on tracks contaminated with leaf, dirt, oil, water, ice and snow.
• Said WSPD of the present invention eliminates flat-spot and blown wheel during aggressive stopping on dry or contaminated tracks.
• Increases Passenger comfort
• Decreases Maintenance cost
• Antiskid system provides a maximum braking efficiency under all track conditions.