Alarm system of rail transit vehicle-mounted PIS system and control method

Abstract

The invention discloses an alarm system of a rail transit vehicle-mounted PIS system and a control method, belongs to the technical field of rail transit, and solves the problems that a single digital channel of an existing alarm system is prone to failure and cannot meet the SIL3 requirement. The system comprises a main / standby alarm path, a double-isolation redundant power supply, a multi-state indicating lamp, a plurality of external communication interfaces, and a control module for monitoring a key state and automatically switching the standby path when the main path fails. An existing PIS framework does not need to be changed, the safety level of the alarm system is improved to SIL3, operation is visual, and operation and maintenance are convenient.

Description

Technical Field

[0001] This application relates to an alarm system and control method for an onboard PIS system of rail transit vehicles. Background Technology

[0002] In the rail transit sector, the Onboard Passenger Information System (PIS) is a core component ensuring operational services and passenger experience. It integrates media display, broadcast control, and video surveillance functions, using an embedded computer system at its core to provide passengers with diversified information services through onboard terminals. Among these, the alarm system, a key submodule of the PIS, plays a crucial role in passenger emergency assistance, driver-passenger communication, and emergency response. It mainly consists of passenger alarms, a broadcast control box, and an Open Control Center (OCC) terminal. Passenger alarms allow passengers to initiate emergency calls, while the broadcast control box is used for manual broadcasts, driver-passenger intercom, and receiving alarm signals, making it a vital link in ensuring the safety of rail transit operations.

[0003] Currently, the alarm systems of existing rail transit vehicle-mounted PIS systems generally adopt a single network digital path design, meaning that alarm signals initiated by passengers and intercom data between drivers and passengers are transmitted through a single digital network link. This design presents significant safety hazards and technical defects in actual operation: when this single digital communication path is interrupted due to network failure, hardware damage, or signal interference, alarm signals cannot be transmitted normally, and the emergency intercom function between drivers and passengers will also fail, resulting in untimely responses to passengers' emergency requests and directly impacting the safety of rail transit operations.

[0004] From a functional safety level perspective, critical equipment in rail transit must meet the Safety Integrity Level (SIL) standards set by the International Electrotechnical Commission (IEC). Alarm systems, as key functional modules affecting personal safety, must meet SIL3 requirements to ensure that the probability of them performing their safe functions within a specified time and under specific conditions meets operational safety needs. However, existing single-path alarm systems, due to a lack of redundancy design, cannot achieve SIL3 and cannot cope with functional failures caused by a single point of failure. This makes them unsuitable for meeting the high reliability and safety requirements of modern rail transit. Therefore, it is urgent to optimize and improve the architecture and transmission mechanisms of existing alarm systems to enhance their safety redundancy and functional reliability. Summary of the Invention

[0005] This application provides an alarm system and control method for an onboard PIS system in rail transit. The technical solution is as follows: On the one hand, an alarm system for a rail transit vehicle-mounted PIS system is provided, including: A main alarm path and a backup alarm path, wherein the alarm paths are connected to an analog communication path via a digital communication path; It is equipped with redundant power modules to provide independent power to the main path and the backup path respectively; At least two indicator lights are used to indicate the working status of the alarm, including power, communication, and fault status. External communication interfaces include an Ethernet communication interface, a debugging interface, and a dry contact interface for connecting alarm devices; The control module is used to monitor the status of the alarm buttons and automatically switch to the backup channel to trigger an alarm when the main channel fails.

[0006] Optionally, the alarm system adopts a dual-channel design, with the main channel being a digital channel and the backup channel being an analog channel, and is connected in a cascaded manner with two lines in and two lines out.

[0007] The optional redundant power supply module adopts a dual power isolation design, with both the main path and the backup path having dual power supply design.

[0008] The alarm panel may optionally be equipped with indicator lights to display power, fault, and communication status.

[0009] Optionally, the alarm can communicate with the vehicle system via an external handheld microphone and be used to indicate fault status.

[0010] Optionally, the external interfaces of the alarm system include a power connection interface, an Ethernet communication interface, an RS232 debugging interface, and a short-circuit dry contact interface.

[0011] Optionally, the alarm has a main path and a backup path, the backup path being used to take over the alarm function; Both the main and backup power supply circuits of the alarm are designed with dual power supplies. The alarm panel design includes two illuminated alarm buttons for operating the alarm functions of the main and backup circuits.

[0012] Optionally, the alarm system employs a dual redundant power supply design.

[0013] On the other hand, a control method for an alarm device in a rail transit vehicle-mounted PIS system is provided, for the alarm device system of the aforementioned rail transit vehicle-mounted PIS system, comprising: The main alarm button is used to activate the main channel alarm signal, and the main alarm button is connected to the main channel of the alarm. When the main alarm path fails, it automatically switches to the backup alarm path. The backup alarm path is activated by the backup alarm button and is connected to the backup path component of the alarm. The control module is used to detect the status of the alarm buttons. When the main alarm button does not respond, the control module instructs the backup alarm path to start working. The control module indicates the working status of the alarm based on the status of the alarm path, and displays the status of the alarm path, fault status and call status through indicator lights. According to the instructions of the control module, switch the external communication interface and transmit the alarm signal to the external receiving device.

[0014] Optionally, after switching to the backup path, the control module sets the volume of the backup alarm path to ensure that the volume is at an appropriate level and can be clearly received by external receiving devices. The alarm communicates with the vehicle system via an external interface and transmits the alarm signal to the vehicle system in real time. The control module is further used to monitor the power status of the alarm. When a power failure occurs, the indicator light will turn off.

[0015] On the other hand, a computer-readable storage medium is provided, wherein a computer program is stored in the computer program, which is loaded and executed by a processor to implement the alarm system method of the rail transit vehicle-mounted PIS system as described above. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the alarm system of the rail transit vehicle-mounted PIS system provided in the embodiments of this application; Figure 2 This is a schematic diagram of the "dual-line in, dual-line out" cascade connection of the main / backup alarm paths in the embodiments of this application; Figure 3 This is a schematic diagram of the actual structure of the alarm panel in the embodiments of this application; Figure 4 This is a schematic diagram of the alarm receiver structure used in conjunction with the alarm in the embodiments of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0018] In this article, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0019] Example 1 On the one hand, an alarm system for a rail transit vehicle-mounted PIS system is provided, including: A main alarm path and a backup alarm path, wherein the alarm paths are connected to an analog communication path via a digital communication path; It is equipped with redundant power modules to provide independent power to the main path and the backup path respectively; At least two indicator lights are used to indicate the working status of the alarm, including power, communication, and fault status. External communication interfaces include an Ethernet communication interface, a debugging interface, and a dry contact interface for connecting alarm devices; The control module is used to monitor the status of the alarm buttons and automatically switch to the backup channel to trigger an alarm when the main channel fails.

[0020] The main alarm path uses a digital Ethernet path (main path), and the backup alarm path uses a PC bus + short-circuit dry contact path (backup path). Both paths are independently connected to the alarm receiver. The redundant power supply module adopts a dual-power isolation design, using a WAGO-4P (5.08mm pitch) connector, with an input of 110VDC. One path powers the microcontroller system and the main path, and the other powers the backup path. Four external indicator lights are provided (power, call, fault, call fault), indicating status through LED color changes (e.g., a constantly lit power light indicates normal operation, a flashing fault light indicates path failure). External communication interfaces include an Ethernet communication interface (cascaded design, connecting to the PIS system), an RS232 debugging interface (reserved for equipment debugging), and a short-circuit dry contact interface (backup path signal transmission). The control module uses a microcontroller minimum operating system (including JTAG debugging, watchdog monitoring, an 11.0592MHz crystal oscillator, and an RS232 debugging serial port), capable of real-time monitoring of the main / emergency alarm path. The backup alarm button status automatically triggers the switch to the backup path when the main path fails (such as an Ethernet interruption), ensuring normal transmission of alarm signals.

[0021] This application addresses the problem of alarm failure caused by a single digital path failure in existing systems. Through a dual-redundancy design with primary and backup dual paths and redundant power supplies, the system's safety integrity level is raised to SIL3, meeting the safety requirements of critical rail transit equipment. Multiple indicator lights provide intuitive feedback on equipment status, allowing for quick fault location without specialized tools (e.g., a lit fault light directly indicates path failure), reducing maintenance complexity. External interfaces are compatible with existing onboard PIS system architectures (e.g., Ethernet-connected PIS), eliminating the need to modify existing systems and reducing application costs. The control module automatically switches paths, avoiding delays caused by manual operation and ensuring timely emergency alarms.

[0022] Example 2 Optionally, the alarm system adopts a dual-channel design, with the main channel being a digital channel and the backup channel being an analog channel, and is connected in a cascaded manner with two lines in and two lines out.

[0023] The main path of the alarm system is a digital Ethernet path (used to transmit alarm signals, volume control commands, and OCC call data), and the backup path is an analog path (composed of a PC bus and short-circuited dry contacts, used only to transmit core alarm signals). Both paths are connected in a cascaded manner with "dual-line input and dual-line output" (as shown in Figure 2). That is, each path has two independent lines at its signal input and output ends. The output end of the previous alarm is directly connected to the input end of the next alarm, forming a cascaded link that covers the entire train car.

[0024] Therefore, the dual-path (digital + analog) design avoids functional failure caused by single-path type failure (such as the overall interruption of the digital network), and the analog path does not rely on complex protocols, resulting in higher stability. The "dual-line input, dual-line output" cascading method ensures that when one line fails, the other line can still transmit signals, avoiding the impact of a single node failure in the cascaded link on the overall alarm function, further improving link reliability, and meeting the SIL3 requirement of "no single point of failure".

[0025] The optional redundant power supply module adopts a dual-power isolation design, with both the main path and the backup path having dual power supplies. The redundant power supply module uses two independent isolated power supply modules (both with 110VDC input), which are symmetrically powered by the interface definition "+, -, +, -" through WAGO-4P connectors. The first isolated power supply only powers the main path system (including the audio codec module and Ethernet circuit) and the microcontroller system, while the second isolated power supply only powers the backup path system (including the short-circuit dry contact circuit and audio operational amplifier). The two power supplies are electromagnetically isolated to avoid mutual interference.

[0026] Therefore, the dual-isolation power supply design ensures that the main and backup power supplies are completely independent. When one power supply fails (such as a short circuit or abnormal voltage), the other power supply is not affected, thus avoiding the problem of "a single power supply failure causing the entire alarm to fail". Isolation design reduces the impact of power ripple and electromagnetic interference on the path signals (such as avoiding interference of main path power noise with backup path analog signals), ensuring the stability of main / backup path signal transmission and indirectly improving the system safety level.

[0027] Optionally, the alarm panel is equipped with indicator lights to display power, fault, and call status. The alarm panel has four external indicator lights: "Power Indicator," "Call Indicator," "Fault Indicator," and "Call Fault Indicator." For the power indicator, a solid green light indicates both power supplies are normal, while a flashing green light indicates a power supply failure. For the call indicator, a solid blue light indicates the current channel (primary / backup) is working normally, while an off blue light indicates a call interruption. For the fault indicator, a solid red light indicates a primary channel fault, while a flashing red light indicates a backup channel fault. For the call fault indicator, a yellow light indicates a malfunction in the echo / sidetone cancellation function of the current channel.

[0028] By accurately distinguishing power, communication, and circuit failure status through different light colors and states, passengers or maintenance personnel can "identify" equipment problems at a glance without connecting debugging tools, greatly improving the efficiency of troubleshooting. The indicator lights are linked to the channel status in real time, providing a clear indication of the "primary and backup channel switching" (e.g., a constantly lit red light indicates that the switch to the backup channel is required), thus avoiding misoperation.

[0029] Optionally, the alarm communicates with the vehicle system via an external handheld microphone and is used to indicate fault status. The alarm receiver (working in conjunction with the alarm system) is an external handheld microphone connected to the receiver host via a dedicated interface. When the main communication channel alarm is triggered, the receiver buzzer sounds. The user can then remove the handheld microphone and press the PTT (transmit button) to communicate with the person triggering the alarm. Simultaneously, the receiver's "main communication indicator light" (blue light) is linked to the microphone; the blue light illuminates when the microphone is removed and turns off when it is hung up. If a communication failure occurs (such as audio signal interruption), the "communication failure indicator light" (yellow light) illuminates, indicating a microphone or communication channel malfunction. Therefore, the external handheld microphone allows for flexible operation by the driver / passenger (e.g., moving around the vehicle to make calls). Compared to a built-in speaker, the microphone provides clearer audio quality and reduces environmental noise interference. The linkage between the microphone and the indicator light allows for quick assessment of the communication status (e.g., the blue light not illuminating indicates the microphone is not properly connected), avoiding the problem of "the call being interrupted without being noticed," and ensuring the effectiveness of driver-passenger coordination after an alarm is triggered.

[0030] Optionally, the external interfaces of the alarm system include a power connection interface, an Ethernet communication interface, an RS232 debugging interface, and a short-circuit dry contact interface.

[0031] In one example, the power connection interface corresponds to a WAGO-4P (5.08mm pitch) connector, with an input of 110VDC and an interface definition of "+, -, +, -", supporting dual power input; the Ethernet communication interface corresponds to an RJ45 interface, using a cascading design, for connecting to the PIS system (transmitting volume control, OCC call data) and other alarms; the RS232 debugging interface corresponds to a DB9 interface, reserved for factory debugging and troubleshooting (such as reading path status logs via serial port); the short-circuit dry contact interface corresponds to a terminal-type interface, used for backup path alarm signal transmission (can still transmit switch signals when there is no power); the PC bus interface corresponds to a terminal-type interface, using a cascading design, for PC bus data transmission of backup paths.

[0032] Optionally, the alarm has a main path and a backup path, the backup path being used to take over the alarm function; Both the main and backup power supply circuits of the alarm are designed with dual power supplies. The alarm panel design includes two illuminated alarm buttons for operating the alarm functions of the main and backup circuits.

[0033] The main path adopts an independent digital circuit design: it includes an audio codec module (to digitize the voice signal), an echo cancellation circuit, and an Ethernet circuit (to transmit digital signals). The circuit relies on a microcontroller system for control. The backup circuit adopts an independent analog circuit design: it only includes a short-circuit dry contact circuit (to trigger the alarm) and an audio operational amplifier (to amplify the analog voice signal), requiring no microcontroller control, and the number of circuit components is 60% less than that of the main circuit; The alarm panel has two illuminated buttons: the main alarm button is located in the center of the panel (20mm×20mm), visible through a transparent window, and its indicator light is green; the backup alarm button is located in the lower right corner of the panel (10mm×10mm), sealed with a lead seal (to prevent accidental activation), and its indicator light is yellow; if the button light does not illuminate when the button is pressed, it indicates that the corresponding circuit is faulty.

[0034] Therefore, both the main and backup circuits are designed with dual power supplies to avoid "one circuit failure affecting the other" (e.g., damage to the Ethernet chip in the main circuit does not affect the audio operational amplifier in the backup circuit), which meets the SIL3 requirement for "functional isolation". The backup circuit is simplified (no microcontroller dependency), reducing the probability of failure and improving reliability in extreme scenarios (e.g., the backup circuit is still usable when the microcontroller crashes). The position, size, and seal design of the dual illuminated buttons guide users to prioritize the use of the main circuit (the large central button is easy to operate), the backup circuit is protected against accidental touches, and the button lights provide intuitive feedback on the circuit status to avoid user misoperation.

[0035] Optionally, the alarm system employs a dual-redundant power supply design. This design utilizes two independent, isolated power supply modules, each with a 110VDC input, supplying power to the main path (including the microcontroller and digital circuitry) and the backup path (including analog circuitry). The power supply modules feature overvoltage and overcurrent protection; when the input voltage exceeds 130VDC or the current exceeds 2A, the output is automatically cut off. Furthermore, the protection circuits for the two power supplies operate independently and do not affect each other.

[0036] Dual redundant power supplies prevent "single point of failure" from the power supply head. Even if one power supply is cut off due to overvoltage / overcurrent protection, the other power supply can still maintain the operation of the corresponding path to ensure that the alarm function is not interrupted. The overvoltage / overcurrent protection function is adapted to the power fluctuation scenarios of rail transit vehicles (such as the instantaneous voltage rise when the train starts), which improves the reliability of the power module itself and indirectly ensures the overall safety level of the alarm.

[0037] Example 3 On the other hand, a control method for an alarm device in a rail transit vehicle-mounted PIS system is provided, for the alarm device system of the aforementioned rail transit vehicle-mounted PIS system, comprising: The main alarm button is used to activate the main channel alarm signal, and the main alarm button is connected to the main channel of the alarm. When the main alarm path fails, it automatically switches to the backup alarm path. The backup alarm path is activated by the backup alarm button and is connected to the backup path component of the alarm. The control module is used to detect the status of the alarm buttons. When the main alarm button does not respond, the control module instructs the backup alarm path to start working. The control module indicates the working status of the alarm based on the status of the alarm path, and displays the status of the alarm path, fault status and call status through indicator lights. According to the instructions of the control module, switch the external communication interface and transmit the alarm signal to the external receiving device.

[0038] In one example, when a passenger triggers an alarm, they first press the main alarm button (center of the panel), activating the main channel (digital Ethernet). The alarm signal is transmitted to the alarm receiver via Ethernet. The control module (microcontroller) monitors the status of the main alarm button in real time. If the button indicator light is off (main channel failure, such as Ethernet interruption), the "fault indicator light" (red light) illuminates, prompting a switch to the backup channel. When the passenger presses the backup alarm button (with a lead seal on the lower right), the backup channel (PC bus + short-circuit dry contact) is activated. The control module automatically switches the external communication interface (from Ethernet to PC bus + dry contact) to transmit the alarm signal to the receiver. The control module provides status feedback through indicator lights: the "talk indicator light" (blue light) illuminates when the main channel is working, the "backup talk indicator light" (yellow light) illuminates when the backup channel is working, and the "fault indicator light" illuminates when there is a fault. During alarm signal transmission, the control module continuously monitors the button status. If the button is released, the corresponding channel signal transmission is automatically terminated.

[0039] Therefore, the "primary first, backup later" control process conforms to user operating habits and can be used without additional training, solving the problem of "complex operation" in existing systems; the control module's real-time detection and automatic switching avoid the risk of "delayed alarm due to manual fault judgment" and ensure alarm response time (≤1s), meeting the SIL3 requirements for "safety function response speed"; the indicator lights are linked with the control logic to realize a closed loop of "operation status feedback", improving the user's control over the equipment status and reducing misoperation.

[0040] Optionally, after switching to the backup path, the control module sets the volume of the backup alarm path to ensure that the volume is at an appropriate level and can be clearly received by the external receiving device; the alarm communicates with the vehicle system through an external interface and transmits the alarm signal to the vehicle system in real time; the control module is further used to monitor the power status of the alarm, and when the power fails, the indicator light will turn off.

[0041] Furthermore, after switching to the backup path, the control module sets the backup path volume to 80dB / 1m by default (clearly audible in a normal carriage environment, and cannot be manually adjusted to avoid accidental adjustment leading to excessively low volume); the alarm communicates with the vehicle-mounted PIS system via an Ethernet interface, transmitting the alarm signal (including alarm time and carriage location) to the PIS host in real time, and simultaneously synchronizing it to the OCC (control center); the control module monitors the status of the dual redundant power supplies through a power detection circuit (series current sensor). If the current of a certain power supply group is 0 (power supply failure), the corresponding "power indicator light" flashes (e.g., if the first power supply group fails, the left half of the green light flashes), and the fault log is output through the RS232 debugging interface. Therefore, the volume of the backup path is fixed at a normal level to avoid "the receiver not being able to recognize the sound due to the low volume" or "the sound being too high and disturbing other passengers," ensuring the effectiveness of alarm signal transmission. The alarm signal is synchronized to the PIS system and OCC in real time, realizing three-level linkage between "passengers, drivers, and OCC" to improve emergency response efficiency (such as the OCC being able to remotely view the alarm location). Power status monitoring and fault log output make it easy for maintenance personnel to quickly locate power failures (such as determining whether the power module is damaged or the line is broken through the log), reducing maintenance costs, and providing early warning of potential power hazards to avoid sudden power outages.

[0042] Example 4 Figure 1 This is a schematic diagram of the overall structure of the rail transit vehicle-mounted PIS system alarm system provided in the embodiments of this application, which is used to intuitively show the composition and connection relationship of each core module of the system.

[0043] like Figure 1 As shown, the core of this alarm system comprises six major components: a main alarm path module, a backup alarm path module, a redundant power supply module, a control module, a multi-state indicator light module, and an external communication interface module.

[0044] 1. Main / Backup Alarm Path Modules. These two modules are designed independently in parallel. The main path module is labeled "Digital Ethernet Path," connecting to the vehicle's PIS system via an Ethernet interface. It integrates an audio codec unit and an echo cancellation unit. The backup path module is labeled "PC Bus + Short-Circuit Dry Contact Path," connecting to the alarm receiver via a terminal interface. Internally, it only retains an analog audio amplification unit and a switch signal transmission unit, reflecting the design logic of "simplifying circuitry to improve reliability."

[0045] 2. Redundant Power Supply Module. Employs a dual-isolation power supply design, labeled "WAGO-4P connector (110VDC input)". It connects the main path module and the backup path module via two independent lines. The lines are labeled "Power Isolation Zone", indicating the electromagnetic isolation structure between the two power supplies, corresponding to the technical feature in the manual that "prevents power interference from affecting path signals".

[0046] 3. Control Module. Based on a "microcontroller minimum system," the module is labeled with "JTAG debugging interface," "Watchdog monitoring unit," and "11.0592MHz crystal oscillator." Control lines connect the button detection terminal and the channel switching terminal of the main / backup path, respectively, illustrating the function of "real-time monitoring of button status and automatic channel switching," corresponding to the feature of "control module monitoring button status" in claim 1.

[0047] 4. Multi-state indicator light module. Four indicator lights are set up, labeled "Power light (green)", "Talk light (blue)", "Fault light (red)" and "Talk fault light (yellow)". They are connected to the output of the control module via signal lines. "Constant on / Flashing" status descriptions are attached next to the lights, corresponding to the description in the manual that "the device status is fed back through light color and status".

[0048] 5. External Communication Interface Module. These are centrally labeled "Ethernet Interface (RJ45)," "RS232 Debug Interface (DB9)," "Short-Circuit Dry Contact Interface (Terminal Type)," and "Power Interface (WAGO-4P)." Each interface connects to the internal system modules via corresponding lines. The Ethernet interface is labeled "Cascading Design," indicating its cascading relationship with other alarms or PIS systems, reflecting that "external interfaces include Ethernet, RS232, and dry contact interfaces."

[0049] Therefore, Figure 1 The overall design clearly presents the core architecture of "dual-path + dual-redundant power supply", intuitively reflecting how the system achieves the SIL3 safety level through independent module design and linkage, providing a foundation for understanding the system's working principle.

[0050] Figure 2 This is a schematic diagram of the "dual-line in, dual-line out" cascaded connection of the main / backup alarm paths in this application embodiment, used to illustrate the cascaded deployment of multiple alarms in a train carriage, corresponding to the technical feature of "dual paths adopting a dual-line in, dual-line out cascaded method" in claim 2.

[0051] like Figure 2 As shown in the figure, three alarms (labeled "Alarm 1", "Alarm 2", and "Alarm 3") are used as an example to simulate the cascading scenario of the entire train carriage.

[0052] 1. Main Path Cascading. Each alarm's main path (digital Ethernet path) is equipped with two sets of two-wire interfaces: "Input A1 / A2" and "Output B1 / B2". The output B1 / B2 of alarm 1 is connected to the input A1 / A2 of alarm 2 via a network cable, and the output B1 / B2 of alarm 2 is connected to the input A1 / A2 of alarm 3, forming a "two-wire serial" link. The end of the link is marked "Connect to Alarm Receiver", indicating that the main path signals of all alarms are ultimately aggregated to the alarm receiver on the train, and each link segment is marked "Ethernet Signal" to clearly indicate the type of transmitted signal.

[0053] 2. Cascading of Backup Paths. Symmetrical to the main path structure, each alarm's backup path (PC bus + short-circuit dry contact path) is also equipped with two sets of two-wire interfaces: "Input C1 / C2" and "Output D1 / D2". It is cascaded using the same two-wire series connection method as the main path, and the end is also connected to the alarm receiver. The link is labeled "PC bus + dry contact signal" to distinguish it from the signal type difference of the main path.

[0054] 3. Fault Redundancy Diagram. Mark the "Fault Point" next to the main input line A1 of alarm 2, and use a dashed line to indicate "Signal Switched to Line A2" to visually demonstrate the redundancy effect of "Dual Line In"—when a single line fails, the signal can be transmitted through the other line, avoiding interruption of the cascaded link due to a single point of failure; similarly, the dual-line design of the backup path also has the same redundancy capability.

[0055] also, Figure 2 The label "covers the entire train carriage" in the upper right corner indicates that this cascading method can expand the number of alarms according to the number of carriages, and the main / backup paths of all alarms are cascaded independently and do not interfere with each other, reflecting the design concept of "dual-path physical isolation". This further supports the system to meet the SIL3 requirement of "no single point of failure" and provides clear wiring guidance for actual engineering deployment.

[0056] Figure 3 This is a schematic diagram of the actual structure of the alarm panel in the embodiment of this application, used to show the external operation and status indication interface of the device, corresponding to the content of "panel setting indicator lights and illuminated alarm buttons".

[0057] like Figure 3 As shown, the panel adopts a rectangular design and marks key dimensional parameters (such as "200±0.5mm" and "225±1mm") to ensure compatibility with the installation space of the vehicle equipment. The panel layout is divided into the following functional areas from left to right and from top to bottom.

[0058] 1. Alarm button area with indicator light. Located on the upper half of the panel, it features two buttons with transparent windows.

[0059] Main alarm button. Labeled "Main Alarm Button," its dimensions are "20mm × 20mm" (a larger size for easy passenger identification and operation). A "green light" is marked inside the button's transparent window to indicate the button's indicator light color, corresponding to the instruction manual's description that "the main button light is green." Backup alarm button. Located to the right of the main button, labeled "Backup Alarm Button", measuring "10mm×10mm" (smaller size). Next to the button is labeled "Lead Seal", indicating that the lead seal is used to prevent accidental activation. Inside the transparent window is labeled "Yellow Light", clearly distinguishing the light color from the main button.

[0060] 2. Multi-status indicator light area. Located in the center of the panel, it consists of 4 horizontally arranged indicator lights, each labeled with "light color + function".

[0061] Power indicator. Labeled "Power (Green)", with a status description next to it: "Steady-on = Dual power supply normal, flashing = Single power supply failure"; Intercom indicator. Labeled "Intercom (blue)," meaning "Still on = call is normal, off = call is interrupted." Fault indicator. Marked "Fault (Red)", indicating "Constantly lit = Main circuit fault, flashing = Backup circuit fault"; Call Fault Indicator. Marked "Call Fault (Yellow)," indicating that "on = echo cancellation / sidetone cancellation abnormal," which perfectly corresponds to the description in the manual that "4 indicator lights indicate different states."

[0062] 3. Interface and Labeling Area. Located on the lower half of the panel, the left side is labeled "Emergency Alarm" and the right side features a small interface area labeled "Power Interface" and "Debugging Interface" to indicate the connection points for external lines. It also labels mounting hole parameters such as "1315" and "15205" for easy installation and securing.

[0063] Figure 3 The physical panel layout clearly demonstrates the human-computer interaction design of "operation-status feedback", which not only reflects the design logic of "guiding the use of the main path first and preventing accidental touch of the backup path", but also reduces the difficulty of operation and maintenance through intuitive light status descriptions, which is in line with the beneficial effect description of "intuitive operation and convenient operation and maintenance" in the manual.

[0064] Figure 4 This is a schematic diagram of the alarm receiver structure used in conjunction with the alarm in this application embodiment. It is used to show the structure of the receiving device for alarm signals, corresponding to the technical content of "the alarm is connected to the alarm receiver through an external interface" in the specification, especially supporting the functional descriptions of "external handheld microphone for communication" and "path status linkage indication".

[0065] like Figure 4As shown, the alarm receiver has a box-like design with key dimensions marked (such as "165±1mm" and "139±1.5mm"). The panel layout is divided into three parts: "indication area", "operation area" and "interface area".

[0066] 1. Indicator Area. Located in the upper half of the panel, it has 4 indicator lights arranged horizontally, labeled "Work Indicator (Green)", "Communication Indicator (Orange)", "Main Line Talk (Blue)" and "Backup Talk (Yellow)".

[0067] Operating indicator light. A solid light indicates that the receiver is powered normally, and it is linked to the power indicator light on the alarm. Communication indicator light. Flashing indicates normal communication with the main / backup communication circuit of the alarm; off indicates communication interruption. Main / backup intercom indicator. These are linked to the main / backup intercom status of the alarm. The blue light illuminates when the main intercom is active, and the yellow light illuminates when the backup intercom is active, corresponding to the description in the instruction manual that "the intercom indicator lights up after the microphone is picked up."

[0068] 2. Operation Area. Located in the center of the panel, it features a "Clear Alarm" button (labeled "Clear Alarm," the red button is for easy emergency operation) and an external handheld microphone interface (labeled "Microphone Interface"). The microphone is connected to the interface via a cable, and next to it is labeled "PTT Transmit Button," indicating the operation procedure of "removing the microphone and pressing the PTT button to make a call," which completely corresponds to the feature of "external handheld microphone communicating with the vehicle system" in claim 5. At the same time, next to the microphone is labeled "Fault Indicator Linkage," indicating that when the microphone malfunctions, the receiver's "Call Fault Light" will illuminate simultaneously.

[0069] 3. Interface Area. Located in the lower half of the panel, this area includes a "Power Interface (110VDC)," a "Main Path Signal Interface (Ethernet)," and a "Backup Path Signal Interface (Dry Contact)." These interfaces are connected to the train power supply and the alarm cascade link via cables. The interface is labeled "Cascaded with Alarm," clearly indicating the connection to the alarm. Additionally, the "CCE" label indicates the communication link between the receiver and the Train Control Center (OCC), supporting the "alarm signal synchronization to OCC" function described in the manual.

[0070] Figure 4 The system demonstrates the complete interactive link between the alarm system's "sender (alarm device) and receiver (receiver)," with a particular emphasis on the design of "linked handheld microphone operation and status indication." This visually reflects how drivers and passengers respond to passenger alarms through the receiver, further refining the overall technical solution of the system and providing a key reference for understanding "driver-passenger coordinated emergency response."

[0071] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0072] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware, or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk. The above descriptions are merely optional embodiments of this application and are not intended to limit the application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An alarm system for a rail transit vehicle-mounted PIS system, characterized in that, include: A main alarm path and a backup alarm path, wherein the alarm paths are connected to an analog communication path via a digital communication path; It is equipped with redundant power modules to provide independent power to the main path and the backup path respectively; At least two indicator lights are used to indicate the working status of the alarm, including power, communication, and fault status. External communication interfaces include an Ethernet communication interface, a debugging interface, and a dry contact interface for connecting alarm devices; The control module is used to monitor the status of the alarm buttons and automatically switch to the backup channel to trigger an alarm when the main channel fails.

2. The alarm system according to claim 1, characterized in that, The alarm system adopts a dual-channel design, with the main channel being a digital channel and the backup channel being an analog channel, and is connected in a cascaded manner with two lines in and two lines out.

3. The alarm system according to claim 1, characterized in that, The redundant power supply module adopts a dual power isolation design, with both the main path and the backup path having dual power supplies.

4. The alarm system according to claim 1, characterized in that, The alarm panel is equipped with indicator lights to display power, fault, and call status.

5. The alarm system according to claim 1, characterized in that, The alarm communicates with the vehicle system via an external handheld microphone and is used to indicate fault status.

6. The alarm system according to claim 1, characterized in that, The external interfaces of the alarm system include a power connection interface, an Ethernet communication interface, an RS232 debugging interface, and a short-circuit dry contact interface.

7. The alarm system according to claim 1, characterized in that, The alarm has a main path and a backup path, and the backup path is used to take over the alarm function. Both the main and backup power supply circuits of the alarm are designed with dual power supplies. The alarm panel design includes two illuminated alarm buttons for operating the alarm functions of the main and backup circuits.

8. The alarm system according to claim 1, characterized in that, The alarm system is designed with dual redundant power supplies.

9. A control method for an alarm device in a rail transit vehicle-mounted PIS system, characterized in that, An alarm system for the rail transit vehicle-mounted PIS system according to any one of claims 1 to 8 includes: The main alarm button is used to activate the main channel alarm signal, and the main alarm button is connected to the main channel of the alarm. When the main alarm path fails, it automatically switches to the backup alarm path. The backup alarm path is activated by the backup alarm button and is connected to the backup path component of the alarm. The control module is used to detect the status of the alarm buttons. When the main alarm button does not respond, the control module instructs the backup alarm path to start working. The control module indicates the working status of the alarm based on the status of the alarm path, and displays the status of the alarm path, fault status and call status through indicator lights. According to the instructions of the control module, switch the external communication interface and transmit the alarm signal to the external receiving device.

10. The control method according to claim 9, characterized in that, After switching to the backup path, the control module sets the volume of the backup alarm path to ensure that the volume is at an appropriate level and can be clearly received by external receiving devices. The alarm communicates with the vehicle system via an external interface and transmits the alarm signal to the vehicle system in real time. The control module is further used to monitor the power status of the alarm. When a power failure occurs, the indicator light will turn off.

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