A self-detecting circuit and method for a switch quantity transmitting interface

Abstract

This invention provides a self-testing circuit and method for a switch signal transmission interface. The circuit includes: a switch signal transmission interface unit, an optocoupler switch control unit, a voltage sampling unit, and a threshold comparison unit. The switch signal transmission interface unit includes optocoupler switch A and optocoupler switch B. The optocoupler switch control unit includes an optocoupler switch control module, which is connected to optocoupler switch A and optocoupler switch B. The voltage sampling unit includes a sampling point voltage divider module, which is connected to optocoupler switch A and optocoupler switch B respectively, for collecting voltage values ​​at points AS and BS. The threshold comparison unit includes a threshold comparison module, which is connected to the sampling point voltage divider module. The self-testing circuit and method of this invention have advantages such as low cost, high accuracy, and high reliability, and are suitable for self-testing of switch signal transmission interfaces in electromechanical systems in the aerospace field.

Description

Technical Field

[0001] This invention relates to the field of avionics technology, specifically to a self-testing circuit and self-testing method for a switch signal transmission interface. Background Technology

[0002] In the field of avionics, the digital input / output interface (DIOI) is a particularly important control interface in electromechanical systems. It can directly or indirectly control onboard signal indicator lights, landing gear retraction / extension, and solenoid valve retraction / extension, among other electromechanical units. If a malfunction of the DIOI during flight causes the signal indicator lights or related electromechanical units to malfunction, and alarm prompts and remedial measures are not quickly and accurately detected, serious consequences will inevitably result. To ensure the accuracy, reliability, and detectability of the DIOI output, specific detection methods have been developed for different DIOI circuits.

[0003] Existing self-testing methods include two approaches: one compares the output command and output electrical signal states to determine consistency. This method involves a loop from the control command terminal to the switch quantity transmitting terminal, resulting in excessive intermediate circuitry and uncontrollable component failures, leading to inaccurate test results. The other approach compares the relay output electrical signal and its state within the circuit. This method uses the aircraft's 28V power supply to form a loop with the relay, and samples the voltage divider signal to determine the relay state. However, this method only considers the aircraft's 28V power supply and neglects the fact that the corresponding equipment's aircraft power supply can range from 16V to 32V, thus resulting in unreliable test results. This invention proposes a novel, low-cost, highly accurate, and highly reliable self-testing method for switch quantity transmitting interfaces. Summary of the Invention

[0004] In view of this, embodiments of this application provide a self-testing circuit and self-testing method for a switch signal transmission interface. The self-testing circuit and method have advantages such as low cost, high accuracy, and high reliability, and are suitable for self-testing of switch signal transmission interfaces in electromechanical systems in the aerospace field.

[0005] The embodiments of this application provide the following technical solution: a self-detection circuit for a switch quantity transmission interface, comprising: a switch quantity transmission interface unit connected to a power supply, and further comprising an optocoupler switch control unit, a voltage sampling unit, and a threshold comparison unit;

[0006] The switch input interface unit includes optical coupler A and optical coupler B, and the optical coupler control unit includes an optical coupler control module, which is controlled and connected to the optical coupler A and optical coupler B.

[0007] The voltage acquisition unit includes an acquisition point voltage divider module, which is connected to optocoupler switch A and optocoupler switch B respectively, for acquiring voltage values ​​at points AS and BS; the threshold comparison unit includes a threshold comparison module, and the acquisition point voltage divider module is connected to the threshold comparison module.

[0008] The voltage divider module at the sampling point transmits the voltage values ​​of points AS and BS to the threshold comparison module. The threshold comparison module compares the sampled value with a first threshold and outputs a first logic value corresponding to the sampling result. Then, it compares the sampled value with a second threshold and outputs a second logic value corresponding to the sampling result. The first logic value and the second logic value are combined to detect the closed / open state of optocoupler switch A and optocoupler switch B.

[0009] Furthermore, it also includes a threshold selection unit, which includes a threshold conditioning module connected to the threshold comparison module. The threshold conditioning module is used to replace the first threshold in the threshold comparison module with the second threshold after the threshold comparison module outputs the first logic value.

[0010] This invention also provides a self-testing method for the self-testing circuit of the switch signal transmission interface as described above, comprising the following steps:

[0011] Step 1: The optocoupler switch control module controls optocoupler switch A to open / close and optocoupler switch B to open / close;

[0012] Step 2: The voltage divider module collects the voltage value of point AS on one side of optocoupler switch A and the voltage value of point BS on one side of optocoupler switch B, and transmits the collected voltage values ​​of points AS and BS to the threshold comparison module.

[0013] Step 3: The threshold comparison module compares the voltage values ​​of points AS and BS with the first threshold and outputs the first logic value corresponding to the sampling result. Then, it compares the voltage values ​​of points AS and BS with the second threshold and outputs the second logic value corresponding to the sampling result. The first logic value and the second logic value are combined to detect the normal closed / open state of the optocoupler switch A and optocoupler switch B.

[0014] Furthermore, the power-on self-test method of this self-test circuit includes the following steps:

[0015] Step 1: Control optocoupler switch A to open and optocoupler switch B to open; collect the voltage values ​​of points AS and BS through the voltage divider module, and obtain the first logic value after comparing them with threshold COM_A and threshold COM_B respectively; change the values ​​of COM_A and threshold COM_B, and obtain the second logic value after comparison; use the combination logic value of the first logic value and the second logic value to detect whether optocoupler switch A and optocoupler switch B can open normally. During this process, the switch quantity transmission remains in the open circuit state.

[0016] Step 2: Control optocoupler switch A to close and optocoupler switch B to open; collect the voltage values ​​of points AS and BS through the sampling point voltage divider module, and obtain the first logic value after comparing them with threshold COM_A and threshold COM_B respectively; change the values ​​of COM_A and threshold COM_B, and obtain the second logic value after comparison; use the combination logic value of the first logic value and the second logic value to detect whether optocoupler switch A can close normally and whether optocoupler switch B can open normally. During this process, the switch quantity transmission remains in the open circuit state.

[0017] Step 3: Control optocoupler switch A to open and optocoupler switch B to close; collect the voltage values ​​of points AS and BS through the sampling point voltage divider module, and obtain the first logic value after comparing them with threshold COM_A and threshold COM_B respectively; change the values ​​of COM_A and threshold COM_B, and obtain the second logic value after comparison; use the combination logic value of the first logic value and the second logic value to detect whether optocoupler switch A can open normally and whether optocoupler switch B can close normally. During this process, the switch quantity transmission remains in the open circuit state.

[0018] Furthermore, the periodic self-testing method of this self-testing circuit includes the following steps:

[0019] Step 1: Set optocoupler switch A to be always closed under normal operating conditions, and optocoupler switch B to close or open according to control commands to realize the transmission of 28V / open type switching signals;

[0020] Step 2: Collect the voltage values ​​of points AS and BS through the voltage divider module at the sampling point, and compare them with threshold COM_A and threshold COM_B respectively to obtain sampling result A and sampling result B, and simultaneously obtain the first logic value 10 or 11; change the values ​​of threshold COM_A and threshold COM_B, compare them again to obtain sampling result A and sampling result B, and simultaneously obtain the second logic value 10 or 11.

[0021] Step 3: Obtain the logical combination value 1010 or 1111 of the sampling result of the voltage values ​​of periodically sampling points AS and BS under normal working conditions. 1010 is the state of no switch quantity transmission, and 1111 is the state of switch quantity transmission. If it does not match the current channel switch quantity transmission command or the current channel switch quantity transmission result, a warning will be reported and optocoupler switch A or optocoupler switch B will be disconnected as needed.

[0022] Compared with the prior art, the beneficial effects achieved by at least one of the above-mentioned technical solutions adopted in the embodiments of this specification include at least the following: the embodiments of this invention use electronic components such as resistors and comparators to design voltage sampling circuits and threshold comparison circuits, resulting in high stability and low cost; the logic values ​​of the sampling results corresponding to different operating states under the on-board power supply range of 16V to 32V are unique, enhancing the reliability of self-detection. The sampling monitoring point is set at the midpoint of the interface path, and the accuracy of self-detection is enhanced by comparing the three parts: the command sent by the switch, the logic value of the sampling result, and the result sent by the switch. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a block diagram illustrating the implementation principle of the self-detection circuit in an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the self-test principle for the transmission status of switch quantities in an embodiment of the present invention;

[0026] Among them, 1-switching quantity transmission interface unit, 2-optical coupler switch control unit, 3-voltage retrieval unit, 4-threshold selection unit, 5-threshold comparison unit, 11-optical coupler switch A, 12-optical coupler switch B; 21-optical coupler switch control module; 31-retrieval point voltage divider module; 41-threshold conditioning module; 51-threshold comparison module. Detailed Implementation

[0027] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments, providing a clear and complete description of the technical solutions of the present invention. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] like Figure 1As shown, this embodiment of the invention provides a self-testing circuit for a switch signal transmission interface, including: a switch signal transmission interface unit 1 connected to the power supply, and also including an optocoupler switch control unit 2, a voltage sampling unit 3, a threshold selection unit 4, and a threshold comparison unit 5;

[0030] The switch input interface unit 1 includes an optocoupler switch A 11 and an optocoupler switch B 12, and the optocoupler switch control unit 2 includes an optocoupler switch control module 21, which is controlled and connected to the optocoupler switch A 11 and the optocoupler switch B 12.

[0031] The voltage acquisition unit 3 includes an acquisition point voltage divider module 31, which is connected to the optocoupler switch A11 and optocoupler switch B12 respectively, and is used to acquire the voltage values ​​at points AS and BS; the threshold comparison unit 5 includes a threshold comparison module 51, which is connected to the acquisition point voltage divider module 31.

[0032] The voltage divider module 31 at the sampling point transmits the voltage values ​​of points AS and BS to the threshold comparison module 51. The threshold comparison module 51 compares the collected value with a first threshold and outputs a first logic value corresponding to the sampling result. The threshold selection unit 4 includes a threshold conditioning module 41 connected to the threshold comparison module 51. After the threshold comparison module 51 outputs the first logic value, it replaces the first threshold in the threshold comparison module 51 with the second threshold. The threshold comparison module 51 then compares the collected value with the second threshold and outputs a second logic value corresponding to the sampling result. The first logic value and the second logic value are combined to detect the closed / open state of the optocoupler switch A11 and optocoupler switch B12.

[0033] This invention employs electronic components such as resistors and comparators to design voltage sampling circuits and threshold comparison circuits, resulting in high stability and low cost. Under the on-board power supply range of 16V to 32V, the logic values ​​of the sampling results corresponding to different operating states are unique, enhancing the reliability of self-testing. The sampling monitoring point is set at the midpoint of the interface path. By comparing the three parts—the command sent via a switch, the logic value of the sampling result, and the result of the switch signal transmission—the accuracy of self-testing is enhanced.

[0034] like Figure 2 As shown, this embodiment of the invention also provides a self-testing method for the self-testing circuit of the switch quantity transmission interface as described above, including the following steps:

[0035] Step 1: The optocoupler switch control module controls optocoupler switch A to open / close and optocoupler switch B to open / close;

[0036] Step 2: The voltage divider module collects the voltage value of point AS on one side of optocoupler switch A and the voltage value of point BS on one side of optocoupler switch B, and transmits the collected voltage values ​​of points AS and BS to the threshold comparison module.

[0037] Step 3: The threshold comparison module compares the voltage values ​​of points AS and BS with the first threshold and outputs the first logic value corresponding to the sampling result. Then, it compares the voltage values ​​of points AS and BS with the second threshold and outputs the second logic value corresponding to the sampling result. The first logic value and the second logic value are combined to detect the normal closed / open state of the optocoupler switch A and optocoupler switch B.

[0038] In specific testing, the self-testing methods include power-on self-test and periodic self-test.

[0039] The power-on self-test method of this self-test circuit includes the following steps:

[0040] Step 1: Control optocoupler switch A to open, and optocoupler switch B to open; collect the voltage values ​​of points AS and BS through the sampling point voltage divider module, and obtain sampling results A and B after comparing them with threshold COM_A and threshold COM_B respectively, with logic values ​​of 1 and 0; change the values ​​of COM_A and threshold COM_B, compare them again to obtain sampling results A and B, with logic values ​​of 0 and 0; use a combined logic value of 1000 to detect whether optocoupler switch A and optocoupler switch B can open normally. During this process, the switch quantity transmission remains in the open circuit state;

[0041] Step 2: Control optocoupler switch A to close and optocoupler switch B to open; collect the voltage values ​​of points AS and BS through the sampling point voltage divider module, and obtain sampling results A and B after comparing them with threshold COM_A and threshold COM_B respectively, with logic values ​​of 1 and 0; change the values ​​of COM_A and threshold COM_B, compare them again to obtain sampling results A and B, with logic values ​​of 1 and 0; use the combined logic value 1010 to detect whether optocoupler switch A can close normally and whether optocoupler switch B can open normally. During this process, the switch quantity transmission remains in the open circuit state.

[0042] Step 3: Control optocoupler switch A to open and optocoupler switch B to close; collect the voltage values ​​of points AS and BS through the sampling point voltage divider module, and obtain sampling results A and B after comparing them with threshold COM_A and threshold COM_B respectively, with a logic value of 0, 0; change the values ​​of COM_A and threshold COM_B, compare them again to obtain sampling results A and B, with a logic value of 0, 0; use the combined logic value 0000 to detect whether optocoupler switch A can open normally and whether optocoupler switch B can close normally. During this process, the switch quantity transmission remains in the open circuit state.

[0043] The periodic self-test method of this self-test circuit includes the following steps:

[0044] Step 1: Set optocoupler switch A to be always closed under normal operating conditions, and optocoupler switch B to close or open according to control commands to realize the transmission of 28V / open type switching signals;

[0045] Step 2: Collect the voltage values ​​of points AS and BS through the voltage divider module at the sampling point, and compare them with threshold COM_A and threshold COM_B respectively to obtain sampling result A and sampling result B, and simultaneously obtain the first logic value 10 or 11; change the values ​​of threshold COM_A and threshold COM_B, compare them again to obtain sampling result A and sampling result B, and simultaneously obtain the second logic value 10 or 11.

[0046] Step 3: Obtain the logical combination value 1010 or 1111 of the sampling result of the voltage values ​​of periodically sampling points AS and BS under normal working conditions. 1010 is the state of no switch quantity transmission, and 1111 is the state of switch quantity transmission. If it does not match the current channel switch quantity transmission command or the current channel switch quantity transmission result, a warning will be reported and optocoupler switch A or optocoupler switch B will be disconnected as needed.

[0047] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A self-test circuit for a digital transmission interface, characterized by The application relates to a self-detection circuit and a power-on self-test method thereof. The switch quantity sending interface unit comprises a photocoupler switch A and a photocoupler switch B, the photocoupler switch control unit comprises a photocoupler switch control module, and the photocoupler switch control module is in control connection with the photocoupler switch A and the photocoupler switch B. The voltage back acquisition unit comprises a back acquisition point voltage division module, the back acquisition point voltage division module is connected with the photocoupler switch A and the photocoupler switch B respectively, and is used for collecting voltage values of point AS and point BS; the threshold value comparison unit comprises a threshold value comparison module, and the back acquisition point voltage division module is connected with the threshold value comparison module. The back acquisition point voltage division module transmits the collected voltage values of point AS and point BS to the threshold value comparison module, the threshold value comparison module compares the collected values with a first threshold value, outputs a first logic value corresponding to a back acquisition result, compares the collected values with a second threshold value, outputs a second logic value corresponding to the back acquisition result, combines the first logic value and the second logic value, and detects the closing / opening state of the photocoupler switch A and the photocoupler switch B. The threshold value selection unit comprises a threshold value conditioning module, the threshold value conditioning module is connected with the threshold value comparison module, and is used for replacing the first threshold value in the threshold value comparison module with the second threshold value after the threshold value comparison module outputs the first logic value.

2. The self-test circuit for a switch-mode transceiver interface according to claim 1, characterized in that The application further discloses a power-on self-test method of the self-detection circuit.

3. A self-test method of a self-test circuit of a switch quantity transmission interface according to claim 1, characterized by, Step 1: the photocoupler switch control module controls the opening / closing of the photocoupler switch A and the photocoupler switch B; Step 2: the back acquisition point voltage division module collects voltage values of point AS on one side of the photocoupler switch A and voltage values of point BS on one side of the photocoupler switch B, and transmits the collected voltage values of point AS and point BS to the threshold value comparison module; Step 3: the threshold value comparison module compares the voltage values of point AS and point BS with a first threshold value, outputs a first logic value corresponding to a back acquisition result, compares the voltage values of point AS and point BS with a second threshold value, outputs a second logic value corresponding to the back acquisition result, combines the first logic value and the second logic value, and detects the normal closing / opening state of the photocoupler switch A and the photocoupler switch B. The power-on self-test method of the self-detection circuit comprises the following steps:

4. The self-test method of a self-test circuit of a switched-mode transmission interface according to claim 3, characterized in that, Step 1: the photocoupler switch A is controlled to be opened, and the photocoupler switch B is controlled to be opened; voltage values of point AS and point BS are collected through the back acquisition point voltage division module, and first logic values are obtained after comparison through threshold value COM_A and threshold value COM_B; the values of COM_A and threshold value COM_B are replaced, second logic values are obtained again after comparison; and the combination logic value of the first logic value and the second logic value is used to detect whether the photocoupler switch A and the photocoupler switch B can be normally opened, and in the process, the switch quantity sending remains in an open circuit state. ​ Step 2: control the photo-coupler switch A to be closed and the photo-coupler switch B to be opened; collect the voltage values of the points AS and BS through the back sampling point voltage dividing module, and obtain the first logic values after comparison through the threshold COM_A and the threshold COM_B respectively; replace the values of the threshold COM_A and the threshold COM_B, and obtain the second logic values after comparison again; use the combined logic values of the first logic values and the second logic values to detect whether the photo-coupler switch A can be normally closed and whether the photo-coupler switch B can be normally opened, and the switch value transmission remains in the open circuit state in the process; Step 3: control the photo-coupler switch A to be opened and the photo-coupler switch B to be closed; collect the voltage values of the points AS and BS through the back sampling point voltage dividing module, and obtain the first logic values after comparison through the threshold COM_A and the threshold COM_B respectively; replace the values of the threshold COM_A and the threshold COM_B, and obtain the second logic values after comparison again; use the combined logic values of the first logic values and the second logic values to detect whether the photo-coupler switch A can be normally opened and whether the photo-coupler switch B can be normally closed, and the switch value transmission remains in the open circuit state in the process.

5. The self-test method of a self-test circuit of a switched-mode transmission interface according to claim 3, characterized in that, The periodic self-checking method of the self-checking circuit comprises the following steps: Step 1: set the photo-coupler switch A to be closed in the normal working state, and set the photo-coupler switch B to be closed or opened according to the control command, so as to realize the transmission of the 28V / open type switch value; Step 2: collect the voltage values of the points AS and BS through the back sampling point voltage dividing module, and obtain the back sampling results A and B after comparison through the threshold COM_A and the threshold COM_B respectively, and obtain the first logic values 10 or 11 synchronously; replace the values of the threshold COM_A and the threshold COM_B, and obtain the back sampling results A and B after comparison again, and obtain the second logic values 10 or 11 synchronously; Step 3: obtain the back sampling result logic combined values 1010 or 1111 of the periodically collected voltage values of the points AS and BS in the normal working state, 1010 is the switch value non-transmission state, 1111 is the switch value transmission state, if it is inconsistent with the current channel switch value transmission command or the current channel switch value transmission result, an alarm is given and the photo-coupler switch A or the photo-coupler switch B is opened according to the need.

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