Patent Application
20240177953
The present invention relates to the field of relay driving, in particular to a processing method for preventing electromagnetic induction when a main system and a standby system of a safety drive unit co-drive a relay.
In the railway signal system, the trackside safety drive unit is configured to perform control commands of an interlocking machine, and output a 24 V direct current (DC) to drive a gravitation type relay of the 6502 relay circuit.
To improve the response speed, two safety drive units that are redundant to each other, generally, do not perform delay driving, but externally output driving power once receiving a drive command. Conventional gravitation type relays are subject to cost considerations, and generally, two drive electric coils are partially wound on a same iron core. As a result, when the relay is driven by a main system board of a redundant system, after the armature is energized, the conducted 24 V DC causes the iron core to generate an induced electromotive force. In addition, if the safety drive unit standby system and the main system drive the relay at the same time, the port state of the output port is detected to be abnormal.
An objective of the present invention is to provide a processing method for preventing electromagnetic induction when a main system and a standby system of a safety drive unit co-drive a relay. The safety drive unit first detects a port state of an output port when a drive command changes, and performs the next processing operation according to the port state. The safety drive unit performs external driving operations only after the port state is normal. The safety drive unit is guided to a safety side method after the port state is detected to be abnormal, which further ensures drive safety.
To achieve the foregoing objective, the present invention is implemented by using the following technical solutions.
The processing method for preventing electromagnetic induction when a main system and a standby system of a safety drive unit co-drive a relay includes:
Optionally, step S104 includes:
Optionally, the enabling the safety drive unit to perform external output operations specifically includes that the safety drive unit performs external driving operations or stops driving according to a drive command.
Optionally, the safety drive unit includes a safety drive unit main system and a safety drive unit standby system, where the safety drive unit main system is connected to a first coil via an output switch A1 and an output switch B1 respectively, and the safety drive unit standby system is connected to a second coil via an output switch A2 and an output switch B2 respectively, and a control logic of the safety drive unit main system is the same as a control logic of the safety drive unit standby system.
Optionally, step S104 includes:
Optionally, the method further includes: in the safety drive unit main system, when the port state is detected to be normal within the set forgiveness cycle, closing the output switch B1, and enabling the safety drive unit main system to perform external output operations.
Optionally, step S104 includes:
Optionally, step S104 includes:
Optionally, before the periodically acquiring and detecting a drive command, the method further includes:
S101, Enabling the safety drive unit to load configuration data and to initialize hardware and software resources.
Optionally, the first coil connected to the safety drive unit main system and the second coil connected to the safety drive unit standby system are wound on a same iron core, and the relay can be driven in case that any one of safety drive units performs external output operations.
Compared with the prior art, the present invention has the following advantages.
In the processing method for preventing electromagnetic induction when a main system and a standby system of a safety drive unit co-drive a relay provided by the present invention, the safety drive unit first detects a port state of an output port when a drive command changes, and performs the next processing operation according to the port state. The safety drive unit performs external driving operations only after the port state is normal. The safety drive unit is guided to a safety side method after the port state is detected to be abnormal, which further ensures drive safety. The method can make the redundant systems co-drive the same relay without delay, avoiding that the ports are detected to be abnormal.
To facilitate understanding of the features, content and advantages of the present invention and the effects that can be achieved, the present invention is described below in detail with reference to implementations and accompanying drawings. The accompanying drawings used herein are intended to only illustrate and assist this specification and do not necessarily show the real scales and precise configurations of the present invention after the implementation. Therefore, the scope of the claims in the present invention is not limited by the interpretation of the scale and configuration relationships.
It should be noted that the accompanying drawings are in a simplified form and in inaccurate scales, and are only used to conveniently and clearly describe the embodiments of the present invention.
As shown in
As shown in
In this embodiment, taking the safety drive unit main system as an example, the port state of the output port of the safety drive unit is determined based on the open/closed states of the output switch A1 and the output switch B1. The hardware reads back the electrical levels on the output switch A1 and the output switch B1, and determines whether the switches can be opened/closed normally according to the permutation and combination. For example, when the output switch A1 and the output switch B1 are both closed, there is a high electrical level on each of them. When the output switch A1 is closed and the output switch B1 is open, there is a low electrical level on the output switch A1 and a high electrical level on the output switch B1. Therefore, the external detection loop is affected by another series of induced electromotive force, and a positive/negative level is superimposed in the detection loop, resulting in an error in the readback electrical level.
Step S104 specifically includes:
Specifically, the enabling the safety drive unit to perform external output operations includes that the safety drive unit drives a corresponding relay externally or stops driving it according to a drive command.
When the drive command of the safety communication module changes from “stop” to “drive”, and the safety drive unit main system or safety drive unit standby system first detects the port states, because the relay is not energized, and no induced electromotive force is generated at the iron core, the detection is passed, and external output operation is performed to drive the relay. Because the relay is driven without delay, the safety drive unit reacted later is disturbed by the magnetic core when detecting the port state, resulting an abnormal detection result, which can be avoided by using the processing method of the present invention.
Further, the processing method for preventing electromagnetic induction when a main system and a standby system of a safety drive unit co-drive a relay in the present invention further includes a safety side processing method, that is, step S104 further includes:
Further, the method further includes: in the safety drive unit main system, which is taken as an example, when the port state is detected to be normal within the set forgiveness cycle, closing the output switch B1, and enabling the safety drive unit main system to perform external output operations, where the same goes for the safety drive unit standby system.
In the present invention, the forgiveness cycle is introduced, and its duration is N detection cycles, and a different forgiveness period can be set according to a relay in a different size. The safety drive unit main system is used as an example. When the port state is detected to be abnormal, and the drive command changes from “stop” to “drive”, within a duration (N detection cycles), it is allowed that the output switch A1 is closed and the output switch B1 is open, and the safety drive unit main system does not enter an unavailable state and waits for the next cycle to detect again. The same goes for the safety drive unit standby system.
S203, in the safety drive unit main system, which is used as an example, when the port state is detected to be abnormal, and if the drive command changes from “stop” to “drive”, and the current cycle is out of the forgiveness cycle, opening the output switch A1 and the output switch B1, and enabling the safety drive unit main system to cut off all outputs to enter an unavailable state, where the same goes for the safety drive unit standby system.
It can be known from the above that during the forgiveness cycle, some switches of the safety drive unit are kept closed, which eliminates repeated opening and closing steps, reduces noise, and improves the life of the on-board relay.
S204, In the safety drive unit main system, which is used as an example, when the port state is detected to be abnormal, and if the drive command changes from “drive” to “stop”, opening the output switch A1 and the output switch B1, and enabling the safety drive unit main system to cut off the output thereof to enter an unavailable state, where the same goes for the safety drive unit standby system.
In summary, in the processing method for preventing electromagnetic induction when a main system and a standby system of a safety drive unit co-drive a relay of the present invention, the safety drive unit first detects a port state of an output port when a drive command changes, and performs the next processing operation according to the port state. The safety drive unit performs external driving operations only after the port state is normal. After the port state is detected to be abnormal, the safety drive unit is guided to a safety side method and cuts off the external outputs, to realize the safe outputs of the safety drive unit through further determining.
Further, in the processing method for preventing electromagnetic induction when a main system and a standby system of a safety drive unit co-drive a relay of the present invention, the forgiveness cycle is set. When the drive command changes from “stop” to “drive”, to further ensure the safety, within the forgiveness cycle, if the port state is abnormal, the detection result of the current cycle is ignored, and the external output operation is not performed. Outside the forgiveness cycle, if the port state is abnormal, the board card enters an unavailable state. That is, the method takes effect only when the port is closed, and does not take effect when the swatch at the port is open, without increasing the safety reaction time, to further ensure the driving safety.
Although the content of the present invention is described in detail in the foregoing preferred embodiments, it should be known that the foregoing description should not be construed as a limitation on the present invention. Various modifications and alternatives to the present invention are apparent to those skilled in the art upon reading the foregoing. Therefore, the protection scope of the present invention should be defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202110692230.9 | Jun 2021 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2021/119227 | 9/18/2021 | WO |
