2. PREAMBLE TO THE DESCRIPTION:

The invention relates to prevention of collisions at railway Level crossings. More particularly this invention is a type of level crossing control system (LxCS), mainly working on a microprocessor based system with triple redundancy at a safety integrity level 3 which when mounted at level crossing gates automatically generates signals for converting and adopting into various safety measures such as activating hooters, operation of barriers, and interfacing with the signalling system. Road users are warned and safe guarded, by activating audio/visual signals. It involves automatic detection of train arrival, generating warning signals to road users, closing and opening of barriers based on the input signals.

3) BACKGROUND OF INVENTION :

Train collisions cause damage to life and property and cause mental trauma to the people involved. The collision of trains with other vehicles such as bus, car etc. at manned level crossings occur due to the mistake of road user or railway staff. Such accidents due to human error were not preventable with the available technology. This kind of mishap i.e collision between trains and road users at level crossings, can be prevented using the current available technology i.e. Level Crossing Control System which works automatically within a desired predetermined range of parameters.

In a conventional system, the barriers at level crossings were controlled manually. On receipt of the train arrival information by some means, the operator operates different controls to generate warnings to road users and close the barriers. Similarly the operator opens the barriers and withdraws the road user warnings after the train passes the level crossing.

By the present invention, on electrical signalling lines the above operations are done automatically. In case of mechanical signalling lines all the operations are automatic except for one manual input viz. train departure from the level crossing. Since the application demands for high level of safety, the system is designed with triple redundancy to meet Safety Integrity Level 3.

In this invention the train arrival is detected from 3 KM distance. The necessary time delays for the road user warnings and barrier closing are programmable.

4) OBTECTIVES OF THE INVENTION

The Overall objective of this invention is to prevent accidents i.e. collision of trains with road vehicles at level crossings by using the LXCS installed at railway crossings. The invention shall allow safe passage of trains at its maximum speed and safe passage of the road traffic over the crossing when it is safe to do so.

Another objective of the invention is to provide audio-visual warning to road users when a train is approaching the level crossing.

Next objective of the invention is to provide correct input to the relay interface based on the barrier condition which is then converted to an appropriate signal so that the locomotive driver can e informed about the condition of the approaching gate.

Further objective is to provide the gateman an indication of the approaching train and train departing the level crossing as well as the status of other modules so that he may take manual actions as required

Next priority shall be for maintaining the logs for the important events during the passage of trains through the level crossings for future analysis in case of any eventuality near the level crossing with respect to the trains. For this apart for textual logs, video recordings are also available.

5) BRIEF DESCRIPTION OF INVENTION:

The heart of the level crossing control system is "Electronic control module" (ECM). There are several sub-systems for generating warnings to road users and for generating signals to railway signalling system.

ECM is based on embedded technology. AH the control logics are performed by the software ported in to the embedded hardware. Since the requirements vary with respect to the complexity of level crossing gates, the control system configurations are programmable at the time of installation.

As explained in the objectives the system was designed as Two out of Three configurations to meet SIL requirements.

Here there are three embedded micro controllers concurrently performing control logics based on the inputs received and generating outputs. All these outputs are routed through a voting module to check 2oo3 confirmation, to generate final output. The voting logic module was provided with redundancy to ensure high availability.

A Service and diagnostic module provided in redundant mode to log the important events and failures from all the three embedded micro controllers during logic control. At the same time some of the external sub-system's health is also monitored by this module. The events and faults recorded by Service and Diagnostic modules are retrieved by Hand Held units through wireless data transmission initiated by Hand Held limits.

Using Hand Held unit the maintenance person can interact with the system to find the health status of sub-systems.

6) DETAILED DESCRIPTION (WITH FIGURES)

The system components with respect to the application are shown in the following figures. As explained above there are two different signalling railway systems viz. electrical and mechanical, on which this level crossing control system can be used.

• LXCS ON ELECTRICAL SIGNALLING LINES

Figure 1 below shows the interconnections between the sub-systems on electrical signalling lines. The train arrival and departure are sensed by the track circuits. The complete operating status including the failures of sub-systems is displayed on the control panel. The operator can interact with the system through the control push buttons provided on the control panel.

• LXCS FOR MECHNICAL SIGNALLING LINES

Figure 2 below shows the interconnections between the sub-systems on mechanical signalling lines.

The train arrival is sensed by the wheel sensing system. Train departure is confirmed by the operator by pressing a push button on the control panel. Un like the electrical system in mechanical system operator interactions are more. The Lx and signal levers are to be operated by the operator.. The complete operating status including the failures of sub-systems is displayed on the control panel. The operator can interact with the system through the control push buttons provided on the control panel

• ELECTRONIC CONTROL MODULE (ECM)

Figure 3 below shows the details of Electronic Control Module (ECM).

Figure 3

ECM is the heart of the Lx Control System. Following are the components of ECM. There are Two sub-racks containing different electronic modules in the ECM. First one contains redundant power supply modules and an Auxiliary module. The second sub-rack contains electronic modules to perform logic controls. As the ECM was designed as 2oo3 system, this sub-rack contains three sections performing all the logics concurrently. Each section contains the following:

• Field Input Interface modules (2 per section)

• Logic processor Module

Three sets of the above modules are configured to form 2-out-of-3 redundant configuration to achieve high safety as well as availability. The other modules in the sub-rack are:

• Two VLM Modules in redundant configuration to achieve high availability
• Two Solid State Relay output modules
• Current sensing module
• Control panel interface modules

Two S&D Processors in redundant configuration were provided for event logging and system diagnostics. These modules contain wireless interface and GSM Communication Modem interface. The S&D module loggs the events and failures declared by each section of ECM duly time stamped. This module also monitors the health status of some of the external sub-systems to indicate on the control panel.

When the above ECM was used on mechanical signalling lines, a wheel sensing system is added, for detecting the train arrival. The wheel sensing system is not required in case of electrical signalling lines.

Relay interfaces were provided to connect the ECM with the existing signalling systems and also for power driving where ever required.

The software reading the field inputs, operator commands to generate necessary output commands is same in all the three sections of ECM.

ECM drives a control panel to indicate the Lx status and sub-system failures to the operator, ECM also reads the commands generated by the operator through the push button switches on the control panel..

7) CLAIMS;

A level crossing control system for usage at railway level crossings to prevent collisions between trains and road vehicles on mechanical and electrical signalling lines is designed. The system comprising of microprocessor based command and control unit (ECM), a barrier control unit, inputs from wheel sensing system or track circuits, audio/visual signals for road users. Control panel with indications and push buttons for the operator and system health monitoring unit. It includes a powers supply, preferably consisting of a battery and power converter, all units and systems functionally interconnected as shown in Figure 1 and Figure 2.

A level crossing control system for usage at railway level crossings, substantially as herein described and illustrated in the figures of the accompanying drawings.

This is a special design conceptualized, designed and developed by kernex Microsystems and meant for medium density and low density routes using COTS components.