A rail transit intrusion detection circuit based on functional safety

Abstract

The present invention discloses a rail transit intrusion detection circuit based on functional safety, which relates to the safety protection design of dangerous areas in rail transit such as subways and light rails. It includes a pressure pad status detection unit and a combinational logic unit of the pressure pad and the threshold switch; the pressure pad status detection unit includes a first pressure pad PM1, a second pressure pad PM2 and a safety relay; the safety relay provides two redundant pressure pad detections, judges the status of the pressure pad by detecting the resistance of the pressure pad, the two pressure pads are detected in parallel, and the detected result statuses are respectively used for alarm and logical operation; the combinational logic unit, on the basis of the pressure pad status detection unit, performs a series processing on the status of the threshold switch and the detection status of the pressure pad; the present invention adopts the way of series processing of the pressure pad and the threshold switch to improve the reliability of the system; adopts the anti-logic design of power-off tripping and the fault detection function to improve the functional safety.

Description

Technical Field

[0001] The present invention relates to a detection circuit design of an anti-intrusion system for dangerous areas of rail transportation such as subways and light rails, and is particularly suitable for preventing people from mistakenly entering dangerous areas in rail transportation. Background Art

[0002] There are some dangerous areas in rail transit such as subways and light rails, such as track areas and distribution rooms. In order to prevent people from mistakenly entering these hazardous areas, it is usually necessary to set up an anti-intrusion detection system. That is, corresponding status detection sensors are set at the entrances leading to the rail transit track area or other dangerous areas. For example, sensors such as threshold switches and pressure pads are set to detect the position of people and the switch status of doors, and these status samples are sent to the intrusion detection system (IDS) for alarm or linkage power-off operations to ensure personnel safety. However, due to the high humidity in the tunnel and the harsh working environment, how to ensure the safe and reliable operation of related sensors is related to the safety and reliability of the entire intrusion detection system. The present invention proposes an intrusion detection system sensor application circuit design based on functional safety to improve the reliability and safety of the intrusion detection system. Summary of the invention

[0003] In order to improve the reliability and safety of the intrusion detection system, the present invention provides pressure pads on both sides of the key entrances and exits. When someone approaches the door and steps on the pressure pads, the corresponding pressure pads will trigger an alarm signal. At the same time, a threshold switch state detection signal is set, and an alarm signal can also be triggered when the door is opened. The triple redundant alarm design can effectively reduce the probability of missed alarms or false alarms in intrusion events. The detailed layout is as follows Figure 1 As shown. Since the pressure pad is set at the place where the door must pass, frequent stepping or heavy objects transported exceeding the bearing capacity of the pressure pad may cause damage to the pressure pad, so it is necessary to detect the health status of the pressure pad in real time, such as Figure 2 As shown, the pressure pads on both sides of the door are connected to the safety relay, which detects the status of people stepping on the pressure pads and can also judge the health status of the pressure pads. If there is a fault, an alarm will be triggered immediately. Finally, the output of the safety relay and the status of the threshold switch are logically combined to generate an alarm or linkage signal to connect to the intrusion alarm system.

[0004] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is: a rail transit intrusion detection circuit based on functional safety, including a pressure pad state detection unit and a combination logic unit of a pressure pad and a threshold switch;

[0005] The pressure pad status detection unit includes a first pressure pad PM1, a second pressure pad PM2, and a safety relay; the safety relay provides two redundant pressure pad detections, determines the status of the pressure pads by detecting the resistance of the pressure pads, the two pressure pads are detected in parallel, and the detected result statuses are respectively used for alarm and logical operation;

[0006] The combination logic unit, based on the pressure pad status detection unit, serially processes the threshold switch status and the detection status of the pressure pads;

[0007] The alarm signal of the pressure pad status detection unit is connected to the logic operation circuit of the combination logic unit;

[0008] The fault signal of the pressure pad status detection unit is connected to the alarm indication circuit of the combination logic unit.

[0009] Further, the combination logic unit includes a power supply, a reset switch S1, a relay K1, a relay K2, a relay K3, a relay K4, a status indicator L1, a status indicator L2, a status indicator L3, and a threshold switch DS1;

[0010] The contact S1(a) of the reset switch S1 is connected to the power supply, the normally closed contact DS1 of the threshold switch, and the normally open contact K1(a) of the relay K1. The coil of the relay K1 is connected to the power supply and the normally closed contact DS1 of the threshold switch. The contact S1(b) of the reset switch S1 is connected to the power supply, the alarm signal PS1 of the safety relay, and the normally open contact K2(a) of the relay K2. The coil of the relay K2 is connected to the power supply and the alarm signal PS1 of the safety relay. The contact S1(c) of the reset switch S1 is connected to the power supply, the alarm signal PS2 of the safety relay, and the normally open contact K3(a) of the relay K3. The coil of the relay K3 is connected to the power supply and the alarm signal PS2 of the safety relay. The normally open contact K1(b) of the relay K1 is connected in parallel with the normally open contact K3(b) of the relay K3 and then connected in series with the normally open contact K2(b) of the relay K2 and the coil of the relay K3 and then connected to the power supply. The normally closed contact K2(c) of the relay K2 is connected in series with the status indicator L1 and then connected to the power supply. The normally closed contact K4(a) of the relay K4 is connected in series with the status indicator L2 and then connected to the power supply. The fault signal AL1 of the safety relay is connected in series with the status indicator L3 and then connected to the power supply. The normally closed contact K2(d) of the relay K2 is connected to the signal acquisition device IDS of the intrusion detection system to achieve alarm. The normally closed contact K4(b) of the relay K4 is connected to the signal acquisition device IDS of the intrusion detection system to achieve linkage.

[0011] Further, the safety relay is an ESD3 safety relay.

[0012] Further, the two pressure pads and the threshold switch DS1 form a triple redundant configuration.

[0013] Further, the pressure pad status detection unit and the combinational logic unit are designed for functional safety with reverse logic for power-off tripping. After pressing the reset switch S1, the system enters the working state. When the system loses power, the sensor is damaged, or the relay is damaged, an alarm signal is automatically triggered, thus realizing the functional safety design. After the relevant alarm is triggered, only when the alarm signal is eliminated and then the reset switch S1 is manually pressed to reset the corresponding alarm can the system enter the working state again.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. The present invention realizes the redundant configuration and fault detection of the pressure pads, improving the reliability of the system;

[0016] 2. The present invention realizes the series connection of the pressure pads and the threshold switch, improving the reliability of the system;

[0017] 3. The present invention realizes the reverse logic design and fault detection function of power-off tripping, achieving functional safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the installation of the pressure pads and the threshold switch in this embodiment.

[0019] Figure 2 It is a schematic diagram of the pressure pad status detection circuit of the intrusion detection circuit in this embodiment.

[0020] Figure 3 It is a schematic diagram of the combinational logic circuit of the intrusion detection circuit in this embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The technical solutions of the present invention will be described in detail below with reference to the drawings and specific embodiments.

[0022] The present invention provides a design of a sensor application circuit for an intrusion detection system based on functional safety to improve the reliability and security of the intrusion detection system; it includes a pressure pad status detection unit and a combinational logic unit of the pressure pads and the threshold switch;

[0023] The pressure pad status detection unit includes a first pressure pad PM1, a second pressure pad PM2, and a safety relay; the safety relay provides two redundant pressure pad detections, judges the status of the pressure pads by detecting the resistance of the pressure pads, the two pressure pads are detected in parallel, and the detected result statuses are respectively used for alarm and logical operation;

[0024] The combined logic unit, based on the pressure pad status detection unit, processes the threshold switch status and the detection status of the pressure pad in series;

[0025] The alarm signal of the pressure pad status detection unit is connected to the logic operation circuit of the combined logic unit;

[0026] The fault signal of the pressure pad status detection unit is connected to the alarm indication circuit of the combined logic unit.

[0027] As Figure 1 shown, the installation schematic diagram of the pressure pad and the threshold switch in this embodiment. A first pressure pad PM1, a second pressure pad PM2, and a threshold switch DS1 are provided on both sides of the door. When someone opens the door and enters the room, the first pressure pad PM1, the threshold switch DS1, and the second pressure pad PM2 are usually triggered in sequence. When the first pressure pad PM1 is triggered, the relay K2 and the status indicator L1 are triggered, and at this time, no relevant safety facilities are linked. When the threshold switch DS1 or the second pressure pad PM2 is further triggered, the linkage relay K4 and the status indicator L2 are triggered.

[0028] As Figure 2 shown, the schematic diagram of the pressure pad status detection circuit in this embodiment. The first pressure pad PM1 and the second pressure pad PM2 are provided on both sides of the door. Under normal circumstances, the resistance of the pressure pad is about 8.2KΩ. When someone steps on the pressure pad, the corresponding pressure will cause a change in the output resistance of the pressure pad, and the safety relay ESD3 will trigger the alarm signal PS1 or PS2 according to the change in resistance. When the resistance of the pressure pad is too large or too small, that is, when the pressure pad has faults such as open circuit or short circuit, the safety relay ESD3 will trigger the fault alarm signal AL1. The alarm signals PS1, PS2 and the fault signal AL1 generated by the pressure pad status detection unit are connected to the combined logic unit.

[0029] As Figure 3 shown, the schematic diagram of the combined logic circuit in this embodiment. It includes a power supply, a reset switch S1, a relay K1, a relay K2, a relay K3, a relay K4, a status indicator L1, a status indicator L2, a status indicator L3, and a threshold switch DS1;

[0030] The contact S1(a) of the reset switch S1 is connected to the power supply, the normally closed contact DS1 of the threshold switch, and the normally open contact K1(a) of the relay K1. The coil of the relay K1 is connected to the power supply and the normally closed contact DS1 of the threshold switch. The contact S1(b) of the reset switch S1 is connected to the power supply, the alarm signal PS1 of the safety relay, and the normally open contact K2(a) of the relay K2. The coil of the relay K2 is connected to the power supply and the alarm signal PS1 of the safety relay. The contact S1(c) of the reset switch S1 is connected to the power supply, the alarm signal PS2 of the safety relay, and the normally open contact K3(a) of the relay K3. The coil of the relay K3 is connected to the power supply and the alarm signal PS2 of the safety relay. The normally open contact K1(b) of the relay K1 is connected in parallel with the normally open contact K3(b) of the relay K3, and then connected in series with the normally open contact K2(b) of the relay K2 and the coil of the relay K3 and then connected to the power supply. The normally closed contact K2(c) of the relay K2 is connected in series with the status indicator L1 and then connected to the power supply. The normally closed contact K4(a) of the relay K4 is connected in series with the status indicator L2 and then connected to the power supply. The fault signal AL1 of the safety relay is connected in series with the status indicator L3 and then connected to the power supply. The normally closed contact K2(d) of the relay K2 is connected to the signal acquisition device IDS of the intrusion detection system to achieve alarm. The normally closed contact K4(b) of the relay K4 is connected to the signal acquisition device IDS of the intrusion detection system to achieve linkage.

[0031] In this intrusion detection sensor application circuit, the two pressure pads and the threshold switch DS1 form a triple redundant configuration. The pressure pad status detection unit and the combinational logic unit are designed with fail-safe logic for power-off tripping. After pressing S1, the system enters the working state. When the system is powered off, the sensor is damaged, or the relay is damaged, an alarm signal is automatically triggered, thus achieving the fail-safe design. After the relevant alarm is triggered, only when the alarm signal is eliminated and then S1 is manually pressed to reset the corresponding alarm can the system enter the working state again.

[0032] The above embodiments are only used to illustrate the technical idea of the implementation of the present invention, and the protection scope of the present invention cannot be limited thereby. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention fall within the protection scope of the present invention. The technologies not involved in the present invention can be realized by existing technologies.

Claims

1. A rail transit intrusion detection circuit based on functional safety, characterized in that: It includes a pressure pad status detection unit and a combinational logic unit of the pressure pad and the threshold switch; The pressure pad status detection unit includes a first pressure pad PM1, a second pressure pad PM2 and a safety relay; the safety relay provides two redundant pressure pad detections, judges the status of the pressure pad by detecting the resistance of the pressure pad, the two pressure pads are detected in parallel, and the detected result statuses are respectively used for alarm and logical operation; The combinational logic unit, on the basis of the pressure pad status detection unit, performs a series processing on the status of the threshold switch and the detection status of the pressure pad; The alarm signal of the pressure pad status detection unit is connected to the logic operation circuit of the combinational logic unit; The fault signal of the pressure pad status detection unit is connected to the alarm indication circuit of the combinational logic unit; The combinational logic unit includes a power supply, a reset switch S1, a relay K1, a relay K2, a relay K3, a relay K4, a status indicator L1, a status indicator L2, a status indicator L3 and a threshold switch DS1; The contact S1(a) of the reset switch S1 is connected to the power supply, the normally closed contact DS1 of the threshold switch and the normally open contact K1(a) of the relay K1. The coil of the relay K1 is connected to the power supply and the normally closed contact DS1 of the threshold switch. The contact S1(b) of the reset switch S1 is connected to the power supply, the alarm signal PS1 of the safety relay and the normally open contact K2(a) of the relay K2. The coil of the relay K2 is connected to the power supply and the alarm signal PS1 of the safety relay. The contact S1(c) of the reset switch S1 is connected to the power supply, the alarm signal PS2 of the safety relay and the normally open contact K3(a) of the relay K3. The coil of the relay K3 is connected to the power supply and the alarm signal PS2 of the safety relay. The normally open contact K1(b) of the relay K1 is connected in parallel with the normally open contact K3(b) of the relay K3 and then connected in series with the normally open contact K2(b) of the relay K2 and the coil of the relay K3 and then connected to the power supply. The normally closed contact K2(c) of the relay K2 is connected in series with the status indicator L1 and then connected to the power supply. The normally closed contact K4(a) of the relay K4 is connected in series with the status indicator L2 and then connected to the power supply. The fault signal AL1 of the safety relay is connected in series with the status indicator L3 and then connected to the power supply. The normally closed contact K2(d) of the relay K2 is connected to the signal acquisition device IDS of the intrusion detection system to achieve alarm. The normally closed contact K4(b) of the relay K4 is connected to the signal acquisition device IDS of the intrusion detection system to achieve linkage.

2. The rail transit intrusion detection circuit based on functional safety according to claim 1, wherein: The safety relay is an ESD3 safety relay.

3. The intrusion detection circuit for rail transit based on functional safety according to claim 1, wherein: The two pressure pads and the threshold switch DS1 form a triple redundant configuration.

4. The intrusion detection circuit for rail transit based on functional safety according to claim 1, characterized in that: The pressure pad status detection unit and the combinational logic unit are designed for functional safety with reverse logic for power-off tripping. After pressing the reset switch S1, the system enters the working state. When the system loses power, the sensor is damaged, or the relay is damaged, an alarm signal is automatically triggered, thus achieving functional safety design. After the relevant alarm is triggered, only when the alarm signal is eliminated and then the reset switch S1 is manually pressed to reset the corresponding alarm can the system enter the working state again.

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