A UI indication system for an airborne oxygen generator

Abstract

The present invention discloses a UI indication system for an airborne oxygen generator, which relates to the field of civil aviation airborne equipment. The system includes a main control MCU, an EMC processing circuit, a fault indicator light circuit, a voltage comparator circuit, a voltage emitter follower circuit, and a power indicator light circuit provided on a UI circuit board; the main control MCU is respectively connected to the voltage emitter follower circuit and the EMC processing circuit; the voltage comparator circuit is connected to the main control MCU; the fault indicator light circuit is connected to the main control MCU; the power indicator light circuit is connected to the voltage comparator circuit; a UI indication system is installed in the main control MCU, which is used to read the fault signal of the oxygen generator, judge the fault type, and generate a control instruction for the fault indicator light according to the judgment result. The present invention can provide status or fault light signals for the airborne oxygen generator, has high reliability, and meets the civil aviation RTCA DO-160G airborne equipment environmental test standard.

Description

Technical Field

[0001] The present invention relates to the field of civil aviation airborne equipment, and particularly to a UI indication system for providing status or fault light signals of an airborne oxygen generator. Background Art

[0002] Modern aircraft often fly at high altitudes (7,000 - 15,000 meters is considered high altitude, and above 15,000 meters is considered ultra-high altitude). To ensure the safety and comfort of crew members during high-altitude flights, civil aviation aircraft are equipped with pressurized cabins. The outside air is pressurized by a pressurization device and then sent into the cabin. The increased air pressure meets the human body's need for oxygen content in the air and can adjust ventilation to make the temperature and humidity meet physiological requirements, providing a comfortable and safe living environment for crew members during high-altitude flights. Taking Boeing airliners as an example, it pressurizes the air through the engine and supplies it into the cabin. Even when the aircraft is flying at an altitude of 10,000 meters, the atmospheric environment inside the cabin is similar to that at an altitude of about 1,500 meters.

[0003] Currently, the Civil Aviation Administration of China (hereinafter referred to as CAAC) requires airlines to operate high-altitude and high-elevation flights (airport elevation ≥ 3,000 meters). When the cabin altitude ≥ 3,000 meters, the on-duty pilots need to supplement oxygen. Airlines generally use the method of equipping spare oxygen cylinders in the cockpit to provide oxygen for pilots, but this method has problems such as limited oxygen cylinder capacity, certain risks in oxygen cylinder storage, and high maintenance and operation costs of oxygen cylinders.

[0004] Now, it is planned to develop an airborne oxygen generator that filters and purifies the oxygen in the air using the principle of molecular sieve oxygen generation to provide oxygen for pilots that meets the corresponding regulations. After preliminary market research, it is found that there is currently no airborne oxygen generator suitable for civil aviation large aircraft and corresponding complete machine engineering solutions on the domestic market.

[0005] During the development of the airborne oxygen generator, it is necessary to independently research and develop the UI module in the airborne oxygen generator to enable the equipment to adapt to the complex airborne electrical operating environment of civil aviation aircraft. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a UI indication system for an airborne oxygen generator, which can provide status or fault light signals for the airborne oxygen generator, has high reliability, and meets the RTCA DO-160G airborne equipment environmental test standard.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A UI indication system for an airborne oxygen generator, comprising a main control MCU, an EMC processing circuit, a fault indicator circuit, a voltage comparator circuit, a voltage follower circuit, and a power indicator circuit arranged on a UI circuit board; the main control MCU is respectively connected to the voltage follower circuit and the EMC processing circuit; the voltage comparator circuit is connected to the main control MCU; the fault indicator circuit is connected to the main control MCU; the power indicator circuit is connected to the voltage comparator circuit; a UI indication system is installed in the main control MCU, configured to read the fault signal of the oxygen generator, judge the fault type, and generate a control instruction for the fault indicator according to the judgment result.

[0009] Specifically, the voltage follower circuit includes a voltage follower and a buzzer, the buzzer is connected to the voltage follower; the voltage follower is connected to the main control MCU.

[0010] The voltage comparator circuit includes a voltage comparator and a current signal input interface, the current signal input interface is connected to the voltage comparator; the voltage comparator is respectively connected to the main control MCU and the power indicator circuit.

[0011] The UI indication system specifically includes an interrupt module, a timer module, a judgment module, and an indicator control module. Among them, the interrupt module is configured to trigger an interrupt event according to an interrupt signal and generate a judgment signal corresponding to the interrupt event;

[0012] The judgment module is configured to perform signal analysis on the judgment signal according to a judgment principle to judge the fault type corresponding to the interrupt event;

[0013] The indicator control module is configured to generate an indicator control instruction according to the fault type judged by the judgment module;

[0014] The timer module is configured to set the main loop value for judging the interrupt signal, the timer timeout value, and the judgment time interval.

[0015] Specifically, the judgment principle specifically includes:

[0016] A: The previous fault cannot be judged as a critical fault or an ordinary fault;

[0017] B: When the previous fault is a critical fault, a next critical fault will occur after an interval of 20S; in this case, the fault time interval is less than 29S;

[0018] C: When the previous fault is an ordinary fault, normally, a next ordinary fault will occur after an interval of 30S. If a fault signal occurs again, the level of this signal must be higher than that of an ordinary signal, that is, a critical fault. Therefore, if the first fault is an ordinary fault and a fault occurs within 29S, then this fault can be judged as a critical fault;

[0019] D: If the interval between the previous fault (whether it is a critical fault or a normal fault) and the subsequent fault signal is 30 seconds, it can be determined that the subsequent fault signal is a normal fault signal.

[0020] E: If the interval between the previous fault (whether it is a critical fault or a normal fault) and the subsequent fault signal exceeds 30 seconds, it can be determined that the fault has disappeared.

[0021] In addition, the system also includes a power interface and a key interface. The power interface is used to connect to an external power supply, and the EMC processing circuit is connected to the power interface. The key interface is used to send a power-on signal, and the main control MCU is connected to the key interface.

[0022] Advantages of the present invention:

[0023] 1. The present invention provides status or fault lighting signals for the airborne oxygen generator, forming a complete airborne oxygen generation solution for large civil aviation transport aircraft.

[0024] 2. The equipment designed by the present invention has high reliability, meets the RTCA DO-160G airborne equipment environmental test standard, and fills the domestic gap.

[0025] 3. The development cost and production cost of the present invention are much lower than the average cost of foreign airborne equipment. Description of the Drawings

[0026] Figure 1 is the principle block diagram of the system equipment of the present invention.

[0027] Figure 2 is the block diagram of the EMC processing circuit.

[0028] Figure 3 is the circuit diagram of the voltage follower.

[0029] Figure 4 is the circuit diagram of the fault indicator light.

[0030] Figure 5 is the circuit diagram of the main control MCU.

[0031] Figure 6 is the circuit diagram of the voltage comparator.

[0032] Figure 7 is the operation logic diagram of the software system. Detailed Embodiments

[0033] For a clearer understanding of the technical features, objectives, and effects of the present invention, the detailed embodiments of the present invention are now described with reference to the drawings.

[0034] In the present invention, the main function of the UI circuit board (UI module) is to provide status or fault light signals for the on-board oxygen generator. The UI module is provided with two LED indicators, one of which is a red / yellow dual-color indicator and the other is a green indicator. The signal input is the fault buzzer signal of the core components of the oxygen generator, and by judging the signal, the indicator combination is controlled to indicate the working status.

[0035] The technical problems solved by the present invention are: to provide an operation status and fault indication function for civil aviation on-board oxygen generators, and the equipment meets the usage standards of civil aviation on-board equipment, specifically including:

[0036] Meet the requirements of Section 17 Voltage Spikes in the environmental conditions and test procedures of RTCA DO-160G on-board equipment;

[0037] Meet the requirements of Section 18 Audio Conducted Susceptibility in the environmental conditions and test procedures of RTCA DO-160G on-board equipment;

[0038] Meet the requirements of Section 19 Induced Signal Susceptibility in the environmental conditions and test procedures of RTCA DO-160G on-board equipment;

[0039] Meet the requirements of Section 20 Radio Frequency Susceptibility (Radiated and Conducted) in the environmental conditions and test procedures of RTCA DO-160G on-board equipment;

[0040] Meet the requirements of Section 21 Radio Frequency Energy Emission in the environmental conditions and test procedures of RTCA DO-160G on-board equipment;

[0041] In view of the above RTCA DO-160G requirements, the present invention designs the UI module circuit to meet the usage requirements of the civil aviation on-board environment. The specific design process is shown in the following embodiments.

[0042] Embodiment 1:

[0043] In this embodiment, as Figure 1 shown, a UI indication system for an on-board oxygen generator includes a main control MCU, an EMC processing circuit, a fault indicator circuit, a voltage comparator circuit, a voltage emitter follower circuit, and a power indicator circuit provided on the UI circuit board; the main control MCU is respectively connected to the voltage emitter follower circuit and the EMC processing circuit; the voltage comparator circuit is connected to the main control MCU; the fault indicator circuit is connected to the main control MCU; the power indicator circuit is connected to the voltage comparator circuit; a UI indication system is installed in the main control MCU for reading the fault signal of the oxygen generator, judging the fault type, and generating a control instruction for the fault indicator according to the judgment result.

[0044] Among them, the fault indicator light includes a red LED and a yellow LED. The red LED is used to indicate important faults, and the yellow LED is used to indicate ordinary faults. The power indicator light circuit includes a power LED, and the power LED is used to indicate the working state of the oxygen generator.

[0045] In this embodiment, the voltage follower circuit includes a voltage follower and a buzzer. The buzzer is connected to the voltage follower; the voltage follower is connected to the main control MCU.

[0046] The voltage comparator circuit includes a voltage comparator and a current signal input interface. The current signal input interface is connected to the voltage comparator; the voltage comparator is respectively connected to the main control MCU and the power indicator light circuit.

[0047] In addition, the system also includes a power interface and a key interface. The power interface is used to connect to an external power supply, and the EMC processing circuit is connected to the power interface. The key interface is used to send a power-on signal, and the main control MCU is connected to the key interface.

[0048] Embodiment 2:

[0049] In this embodiment, the device circuit mainly includes an EMC processing circuit, a voltage follower, a fault indicator light circuit, a voltage comparator, a power indicator light circuit, and a main control MCU circuit. This embodiment further conducts a detailed design on the module circuit architecture provided in Embodiment 1. The specific design contents include the following aspects:

[0050] 1. EMC processing circuit

[0051] The EMC processing circuit is used to filter out EMI and ESD interference between the UI module and other device modules, and handle the mutual interference. Its reference circuit is as Figure 2 shown.

[0052] 2. Voltage follower circuit

[0053] The voltage follower circuit is located between the buzzer and the UI module. The buzzer is located on the core circuit of the oxygen generator. To avoid the influence of the UI module on the core circuit of the oxygen generator, the follower circuit uses TL9301 with extremely high input impedance, and the shunt to the core circuit of the oxygen generator is extremely small. TL9301 internally contains an EMI filter, which can filter out the EMI of the core circuit of the oxygen generator from interfering with the UI module. At the same time, it serves as an impedance match between the two modules. The relevant circuit of the voltage follower circuit is as Figure 3 shown.

[0054] 3. Fault indicator light circuit

[0055] The fault indicator light circuit is used to indicate the fault status of the oxygen generator. The ordinary fault is indicated by a yellow light, and the important fault is indicated by a red light. The control signal is provided by the main control MCU. The reference circuit of the fault indicator light circuit is as Figure 4 shown.

[0056] 4. Main control MCU circuit

[0057] The core of the main control MCU circuit is the STC89C52 launched by STC Company. This chip is a single-chip microcomputer of the STC89C52 series, with characteristics such as high speed / low power consumption / strong anti-interference, and the instruction code of the enhanced 8051 single-chip microcomputer is completely compatible with the traditional 8051. The relevant parameters of the main control MCU circuit are as follows: operating voltage: 5.5V~3.8V; operating frequency: 0~35MHZ; 1280 bytes are integrated on the chip; it has EEPROM function; watchdog; operating temperature range: -40°C~+85°C; package: LQFP-44, PDIP-40, PLCC-44, PQFP-44. The main control MCU circuit is as Figure 5 shown.

[0058] 5. Voltage comparator circuit

[0059] The voltage comparator circuit compares the current signal input from the power supply module to the UI module with the reference signal. The circuit design idea is to compare the voltage signal input from the power supply module with the reference signal. When it is higher than the reference signal, the comparator outputs a high level and lights up the LED lamp. The input voltage of the power supply module is converted from the current signal. The greater the current, the higher the voltage. The reference signal is obtained by voltage division of the power supply voltage. Finally, when the output current of the power supply module is greater than 1A, the LED lamp lights up. Its circuit is as Figure 6 shown.

[0060] The UI circuit board designed in this embodiment can provide status or fault light signals for the airborne oxygen generator, forming a complete airborne oxygen generation solution for large civil aviation transport aircraft. At the same time, the equipment has high reliability, meets the RTCA DO-160G airborne equipment environmental test standard, fills the domestic gap, and the overall development cost and production cost of the equipment are much lower than the average cost of foreign airborne equipment.

[0061] Example three:

[0062] In this embodiment, based on the hardware device provided in Embodiment 2, an embedded UI indication system for processing the data of the hardware device is specifically designed. The main software function to be implemented by the system is to read the fault signal of the oxygen generator, then judge the fault type, and after the judgment is completed, display the fault in the form of an indicator light. It mainly consists of an interrupt module, a timer module, a judgment module, and an indicator light control module. Among them, the interrupt module is used to trigger an interrupt event according to the interrupt signal and generate a judgment signal corresponding to the interrupt event. The judgment module is used to perform signal analysis on the judgment signal according to the judgment principle to judge the fault type corresponding to the interrupt event. The indicator light control module is used to generate an indicator light control instruction according to the fault type judged by the judgment module. The timer module is used to set the main loop value of the interrupt signal judgment, the timer timeout value, and the judgment time interval.

[0063] In this embodiment, the system logic is as Figure 7 shown. Among them, interrupt triggering: The interrupt triggering adopts falling-edge triggering. Since the interrupt signal is normally at a high level, when a triggering event occurs, the level is pulled low, so falling-edge triggering is adopted.

[0064] For the judgment signal, judge again whether the triggering signal is indeed a complete triggering signal, and determine it as a low-level triggering signal. Then proceed to the next step; otherwise, do not process and exit the interrupt.

[0065] The time interval judgment is also the fault type judgment, and its judgment principle is as follows:

[0066] 1: The previous fault cannot be judged as a major fault or an ordinary fault;

[0067] 2: When the previous fault is a major fault, a next major fault will occur after an interval of 20S; in this case, the fault time interval is less than 29S.

[0068] 3: When the previous fault is an ordinary fault, normally, a next ordinary fault will occur after an interval of 30S. If a fault signal occurs again, the level of this signal must be higher than that of an ordinary signal, that is, a major fault. Therefore, if the first fault is an ordinary fault and a fault occurs within 29S, then this fault can be judged as a major fault.

[0069] 4: Whether the previous fault is a major fault or an ordinary fault, if the interval from the previous fault to the next fault signal is 30S, it can be judged that the next fault signal is an ordinary fault signal.

[0070] 5: Whether the previous fault is a major fault or an ordinary fault, if the interval from the previous fault to the next fault signal exceeds 30S, it can be judged that the fault has disappeared.

[0071] In this embodiment, on the basis of the designs of the above-mentioned Embodiment 1 and Embodiment 2, a comprehensive design of the system is also carried out. The design contents include:

[0072] I. Environmental adaptability design

[0073] 1. Temperature and humidity

[0074] In the PCB board layout of the module designed in this embodiment, heat dissipation is fully considered. A large number of vias are used for heat dissipation around the heat source. The devices are distributed relatively evenly, which is conducive to heat dissipation. All devices use devices with a working temperature not lower than the temperature range of -25°C to 85°C. It meets the working temperature range of -15°C to 55°C for this type of attribute module in DO160-G.

[0075] The PCB board uses a circuit board that meets the GB4588 standard to ensure the environmental adaptability of the circuit board. During the production process of the circuit board surface, three-proof treatment is carried out to avoid damage to the circuit board in a humid and hot environment.

[0076] 2. Electromagnetic compatibility

[0077] In the module circuit design of this embodiment, 2-level EMI processing is added before and after. The housing uses plastic parts except for the top, and the rest are all metal parts and are grounded.

[0078] 3. Shock resistance

[0079] The devices used on the module in this embodiment are all surface-mounted devices, avoiding tall and straight plug-in devices that are not conducive to shock. The PCB board uses a circuit board that meets the GB4588 standard to ensure the shock resistance of the circuit board. The production place of the module is a patch factory that produces high-reliability military circuit boards. The devices used themselves have high-strength shock resistance.

[0080] II. Manufacturability design

[0081] All devices in this embodiment use currently mass-produced devices. When large-scale production is carried out later, the situation of large-area out-of-stock or device production suspension during the batch production process can be avoided.

[0082] The circuit board design is processed according to the conventional design. There are no special packaging devices, no special manual operation devices, and no special process requirements, which is convenient for large-scale production.

[0083] III. Safety design

[0084] In the design process of the module in this embodiment, safety is fully considered: There are no sharp edges on the circuit board to avoid scratching. The selected devices are not flammable, explosive, and in extreme cases, no open fire or toxic gas will be generated. The surface of the module is sprayed with flame retardant to prevent internal and external combustion.

[0085] IV. Compliance design

[0086] In the design process of the modules in this embodiment, it is strictly carried out in accordance with the design requirements specification, following RTCA / DO-16-G, RTCA / DO-313 and relevant standards of AVIC.

[0087] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. An UI indication system for an airborne oxygen generator, characterized in that, It includes a main control MCU, an EMC processing circuit, a fault indicator circuit, a voltage comparator circuit, a voltage emitter follower circuit, and a power indicator circuit provided on the UI circuit board; the main control MCU is respectively connected to the voltage emitter follower circuit and the EMC processing circuit; the voltage comparator circuit is connected to the main control MCU; the fault indicator circuit is connected to the main control MCU; the power indicator circuit is connected to the voltage comparator circuit; a UI indication device is installed in the main control MCU, which is used to read the fault signal of the oxygen generator, judge the fault type, and generate a control instruction for the fault indicator according to the judgment result; The voltage emitter follower circuit includes a voltage emitter follower and a buzzer, and the buzzer is connected to the voltage emitter follower; the voltage emitter follower is connected to the main control MCU; The voltage comparator circuit includes a voltage comparator and a current signal input interface, and the current signal input interface is connected to the voltage comparator; the voltage comparator is respectively connected to the main control MCU and the power indicator circuit; The UI indication device specifically includes an interrupt module, a timer module, a judgment module, and an indicator control module. Among them, the interrupt module is used to trigger an interrupt event according to an interrupt signal and generate a judgment signal corresponding to the interrupt event; The judgment module is used to perform signal analysis on the judgment signal according to the judgment principle to judge the fault type corresponding to the interrupt event; The indicator control module is used to generate an indicator control instruction according to the fault type judged by the judgment module; The timer module is used to set the main loop value of the interrupt signal judgment, the timer timeout value, and the judgment time interval; The judgment principle specifically includes: A: The previous fault cannot be judged as a major fault or an ordinary fault; B: When the previous fault is a major fault, a next major fault will occur after an interval of 20S; in this case, the fault time interval is less than 29S; C: When the previous fault is an ordinary fault, normally, a next ordinary fault will occur after an interval of 30S. If a fault signal occurs again, the level of this signal must be higher than that of an ordinary signal, that is, a major fault. Therefore, if the first fault is an ordinary fault and a fault occurs within 29S, this fault is judged as a major fault; D: Whether the previous fault is a major fault or an ordinary fault, if the interval from the previous fault to the next fault signal is 30S, then the next fault signal is judged as an ordinary fault signal; E: Whether the previous fault is a major fault or an ordinary fault, if the interval from the previous fault to the next fault signal exceeds 30S, then it is judged that the fault has disappeared.

2. The UI indication system for an airborne oxygen generator according to claim 1, characterized in that, It further includes a power interface for accessing an external power supply, and the EMC processing circuit is connected to the power interface.

3. The UI indication system for an airborne oxygen generator according to claim 1, characterized in that, It further includes a key interface for sending a power-on signal, and the main control MCU is connected to the key interface.

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