Double-cavity underwater wireless data monitoring system for diving respirator

Abstract

The double-cavity underwater wireless data monitoring system for the diving respirator comprises a gas detection device and a gas display device, the gas detection device comprises a hollow first waterproof shell, a waterproof partition plate is fixed in the middle of the first waterproof shell, and an inner cavity of the first waterproof shell is divided into a closed normal pressure cavity and a variable pressure cavity by the waterproof partition plate; a normal-pressure cavity sealing ring and a normal-pressure cavity upper cover are fixed to the top of the first waterproof shell and located over the closed normal-pressure cavity, a control key is embedded in the normal-pressure cavity upper cover, a battery, a control circuit board and an antenna are fixed in the closed normal-pressure cavity, and a transformation cavity sealing ring and a transformation cavity upper cover are fixed to the top of the first waterproof shell and located over the transformation cavity. The front side of an upper cover of the variable-pressure cavity is fixedly connected with an inspiration gas outflow connector of an upper inspiration pipeline of the respirator, the front side of a bottom shell of the first waterproof shell is located under the variable-pressure cavity and fixedly connected with an inspiration gas inflow connector of a lower inspiration pipeline of the respirator, an installation plate is fixed in the variable-pressure cavity, and a differential pressure sensor and a gas concentration sensor are fixed to the installation plate.

Description

Technical Field

[0001] The invention relates to the technical field of submersible breathing apparatus for divers, and in particular to a double-chamber underwater wireless data monitoring system for submersible breathing apparatus. Background Art

[0002] Real-time monitoring technology for breathing gas is a general trend in the development of underwater breathing apparatus safety. In view of the safety of air supply for underwater diving operations, there are no reports or applications of mature products that can be used with diving breathing apparatus in high-pressure underwater environments and monitor gas concentration in breathing apparatuses.

[0003] The inventor of the present invention previously applied for an invention patent with application number: 202410559489X, entitled A closed respirator breathing gas oxygen concentration monitoring system. In this patent, a cylindrical tube is set in the internal cavity of the detection host, and the internal cavity of the detection host is divided into two concentric cavities by the cylindrical tube. The present invention improves this structure by dividing the internal cavity into two cavities separated on the left and right, and based on this, a dual-chamber underwater wireless data monitoring system for a submersible respirator is designed. Summary of the invention

[0004] The present invention aims at the problems and shortcomings of the prior art and provides a double-chamber underwater wireless data monitoring system for a diving breathing apparatus.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The present invention provides a dual-chamber underwater wireless data monitoring system for a diving breathing apparatus, which is characterized in that it includes a gas detection device and a gas display device, the gas detection device includes a first waterproof shell with a hollow inner cavity, a waterproof baffle is fixed in the first waterproof shell, so that the hollow inner cavity of the first waterproof shell is divided by the waterproof baffle into a closed normal pressure chamber without gas exchange and a variable pressure chamber with gas exchange, which are separated and arranged on the left and right, a normal pressure chamber sealing ring and a normal pressure chamber upper cover are fixed in sequence on the top of the first waterproof shell and located directly above the closed normal pressure chamber, a control button is embedded in the normal pressure chamber upper cover, a battery, a control circuit board and an antenna are fixed in the closed normal pressure chamber, and the A transformer chamber sealing ring and a transformer chamber upper cover are fixed in sequence on the top of the first waterproof shell and located directly above the transformer chamber; an air intake gas outflow joint for connecting the upper air intake pipeline of a closed submersible breathing apparatus is fixed on the front side of the transformer chamber upper cover; an air intake gas inflow joint for connecting the lower air intake pipeline of a closed submersible breathing apparatus is fixed on the front side of the bottom shell of the first waterproof shell and located directly below the transformer chamber; a mounting plate is fixed in the transformer chamber near the position where the air intake gas inflow joint is installed; a differential pressure sensor and a gas concentration sensor are fixed on the mounting plate; the control button, differential pressure sensor, gas concentration sensor, antenna and battery are all electrically connected to the control circuit board;

[0007] The gas display device comprises a second waterproof shell with a hollow inner cavity, a display is embedded in the second waterproof shell, a wireless radio frequency receiving module, a power supply, a power management module and a main microcontroller are arranged in the second waterproof shell, the wireless radio frequency receiving module and the display are electrically connected to the main microcontroller, and the power supply is electrically connected to the main microcontroller through the power management module;

[0008] The control circuit board is used to enter a working state upon receiving a start signal from a control button, receive a pressure difference between an inhalation gas inflow joint and an inhalation gas outflow joint detected by a pressure difference sensor, indicate that a diver is inhaling using a closed-circuit submersible breathing apparatus when a pressure difference exists, and indicate that a diver is exhaling using a closed-circuit submersible breathing apparatus when no pressure difference exists, and when the diver is exhaling using a closed-circuit submersible breathing apparatus based on the pressure difference value of the pressure difference sensor, receive a gas concentration value detected by a gas concentration sensor and send it out through an antenna;

[0009] The main microcontroller is used to receive the gas concentration value through the wireless radio frequency receiving module and display it through the display.

[0010] Furthermore, a transformer cavity temperature and humidity sensor and a transformer cavity pressure sensor are also fixed in the transformer cavity, and a power management circuit, a main control circuit, a signal conditioning circuit, an ADC circuit, an IIC interface and a wireless transmission circuit are provided on the control circuit board. The battery is electrically connected to the main control circuit through the power management circuit, the gas concentration sensor is electrically connected to the ADC circuit through the signal conditioning circuit, the differential pressure sensor is electrically connected to the ADC circuit, the transformer cavity temperature and humidity sensor and the transformer cavity pressure sensor are both electrically connected to the main control circuit through the IIC interface, the ADC circuit, the IIC interface, the control button, the indicator light and the wireless transmission circuit are all electrically connected to the main control circuit, and the wireless transmission circuit is electrically connected to the wireless radio frequency receiving module through the antenna;

[0011] The main control circuit is used to enter a low power consumption state upon receiving a long press signal of the control button. At this time, the pressure value of the transformer chamber pressure sensor is continuously read through the IIC interface to determine whether the diver has entered the water. When the pressure value reaches the water entry set pressure value, it is determined that the diver has entered the water. At this time, the gas concentration sensor, the differential pressure sensor, the transformer chamber temperature and humidity sensor, and the antenna start to work, and the gas detection device enters a normal working state until it detects that the pressure value of the transformer chamber pressure sensor is at normal pressure, that is, the gas detection device is out of water, then exits the normal working state and enters a low power consumption state; or, the main control circuit is used to enter a low power consumption state upon receiving a long press signal of the control button, and then when a double-click signal of the control button is received, the gas detection device enters a normal working state until it detects that the pressure value of the transformer chamber pressure sensor is at normal pressure, that is, the gas detection device is out of water, then exits the normal working state and enters a low power consumption state;

[0012] The differential pressure sensor is used to detect the differential pressure signal between the inhaled gas inflow joint and the inhaled gas outflow joint, and the ADC circuit is used to convert the differential pressure signal into digital form and transmit it to the main control circuit;

[0013] The gas concentration sensor is used to detect the gas concentration signal in the transformer cavity, the signal conditioning circuit is used to filter, impedance match and amplify the gas concentration signal, and the ADC circuit is used to convert the conditioned gas concentration signal into digital form and transmit it to the main control circuit;

[0014] The transformer cavity temperature and humidity sensor is used to detect the temperature and humidity in the transformer cavity and transmit it to the main control circuit via the IIC interface;

[0015] The main control circuit is used to analyze the diver's exhalation using a closed-circuit diving breathing apparatus based on the pressure difference signal, receive the gas concentration signal and perform temperature, humidity and pressure compensation on the gas concentration signal, perform digital-to-analog conversion on the compensated gas concentration signal and send it through the antenna after amplification by the wireless transmission circuit signal;

[0016] The power management circuit is used to provide supply voltages of +12V, VCC5V and VCC 3.3V.

[0017] The positive and progressive effects of the present invention are:

[0018] The internal cavity of the gas detection device designed by the present invention is divided into two parts separated on the left and right: a closed normal pressure cavity without gas exchange and a variable pressure cavity with gas exchange. The closed normal pressure cavity without gas exchange is equipped with circuit components such as batteries, control circuit boards, antennas, etc. Through a closed assembly method, it is always in a normal pressure environment, and there is no pressure change. The requirements for components will be greatly reduced, and reliability is guaranteed; the variable pressure cavity with gas exchange will be connected to the sampling pipeline to maintain the same air pressure as the closed diving respirator. Gas concentration sensors, differential pressure sensors, temperature and humidity sensors, and absolute pressure sensors are deployed in the cavity. All components in this part will meet the conditions of withstanding 7 bar atmospheric pressure.

[0019] The present invention can analyze that a diver is exhaling using a closed-circuit submersible breathing apparatus based on the pressure difference signal of the pressure difference sensor, at which time a gas concentration signal from a gas concentration sensor is received and temperature, humidity and pressure compensation is performed on the gas concentration signal, and the compensated gas concentration signal is sent to a receiving end via an antenna, and the receiving end displays the gas concentration in the air intake pipeline of the closed-circuit submersible breathing apparatus.

[0020] The components and components of the gas detection device of the present invention have different tolerance to high pressure due to their own principles and physical structural characteristics. The present invention takes into account the difference in the capabilities of components and components, that is, the sensors for gas concentration detection, gas temperature, humidity, and pressure detection must withstand pressure changes as the depth of the diving operation changes. For lithium batteries and electronic components, maintaining constant pressure can reduce the risk of failure caused by pressure changes or pressure overruns. Based on the above prerequisites, a dual-chamber gas detection device structure is designed. Under this structure, the components that must be in contact with the gas are placed in the pressure-changing chamber, and the lithium battery and electronic components are placed in the constant pressure chamber, that is, the chamber is divided into two parts: a sealed chamber and a pressure-changing chamber. These two parts not only realize the separation of gas and electricity, but also break down the problem into parts, and are designed and improved in a targeted manner to protect relatively fragile components and components to the maximum extent. Moreover, placing the components in two chambers according to their pressure-resistant capabilities is conducive to protecting the safety of lithium batteries and electronic components, improving the stability and reliability of the product operation, reducing the ineffective space of the gas circulation chamber, and thus increasing the gas update rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional diagram of an oxygen detection device according to a preferred embodiment of the present invention.

[0022] Figure 2-3Schematic diagram of the internal structure of an oxygen detection device according to a preferred embodiment of the present invention.

[0023] Figure 4 This is a design diagram of the internal cavity of the oxygen detection device according to a preferred embodiment of the present invention.

[0024] Figure 5 1 is a circuit diagram of an oxygen detection device according to a preferred embodiment of the present invention.

[0025] Figure 6 It is a three-dimensional diagram of an oxygen display device according to a preferred embodiment of the present invention.

[0026] Figure 7 FIG. 4 is a circuit diagram of a main control circuit according to a preferred embodiment of the present invention.

[0027] Figure 8 FIG. 4 is a circuit diagram of a wireless transmitting circuit according to a preferred embodiment of the present invention.

[0028] Fig. 9 FIG. 4 is a circuit diagram of a signal conditioning circuit according to a preferred embodiment of the present invention.

[0029] Fig.10 FIG. 4 is a circuit diagram of a power management circuit according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] This embodiment provides a dual-chamber underwater wireless data monitoring system for a submersible breathing apparatus, which includes an oxygen detection device and an oxygen display device, and the two parts communicate via wireless radio frequency. The oxygen detection device is installed on the air intake pipe of the closed-circuit submersible breathing apparatus and can detect the oxygen concentration on the air intake pipe; the oxygen display device is an underwater computer table, which is equipped on the diver's wrist for easy data reading.

[0032] like Figure 1-4As shown, the oxygen detection device includes a first waterproof shell 1 with a hollow inner cavity, a waterproof baffle 2 is fixed at the middle position of the first waterproof shell 1, the first waterproof shell 1 and the waterproof baffle 2 are integrally formed, the hollow inner cavity of the first waterproof shell 1 is divided into a closed normal pressure chamber 3 without gas exchange and a variable pressure chamber 4 with gas exchange by the waterproof baffle 2, the top of the first waterproof shell 1 and located directly above the closed normal pressure chamber 3 are fixed with a normal pressure chamber sealing ring 5 and a normal pressure chamber upper cover 6 in sequence, a control button 7, an indicator light 8 and a contact 9 are embedded on the normal pressure chamber upper cover 6, a battery 10, a control circuit board 11 and an antenna 12 are fixed in the closed normal pressure chamber 3, a variable pressure chamber sealing ring 13 and a variable pressure chamber upper cover 6 are fixed in sequence on the top of the first waterproof shell 1 and located directly above the variable pressure chamber 4 The upper cover 14 of the cavity, the front side of the upper cover 14 of the transformer cavity is provided with an intake gas outflow joint 15, the intake gas outflow joint 15 is used to connect the upper intake pipeline of the closed submersible breathing apparatus, the front side of the bottom shell of the first waterproof shell 1 and directly below the transformer cavity 4 is provided with an intake gas inflow joint 16, the intake gas inflow joint 16 is used to connect the lower intake pipeline of the closed submersible breathing apparatus, and a mounting plate 17 is fixed near the position where the intake gas inflow joint 16 is installed in the transformer cavity 4, and a pressure difference sensor 18 and an oxygen concentration sensor 19 are fixed on the mounting plate 17, and the control button 7, indicator light 8, contact 9, antenna 12, pressure difference sensor 18, oxygen concentration sensor 19 and battery 10 are all electrically connected to the control circuit board 11.

[0033] Among them, the normal pressure chamber sealing ring 5 adopts a silicone sealing ring, and the normal pressure chamber sealing ring 5 is composed of a normal pressure chamber upper sealing ring matching the top shell edge of the closed normal pressure chamber 3 and a normal pressure chamber lower sealing ring matching the inner wall of the closed normal pressure chamber 3. The normal pressure chamber upper sealing ring and the normal pressure chamber lower sealing ring are integrally formed, the normal pressure chamber lower sealing ring is placed in the closed normal pressure chamber 3 and fits the inner wall of the closed normal pressure chamber 3, and the normal pressure chamber upper sealing ring is fixed on the top of the closed normal pressure chamber 3 and fits the top shell edge of the closed normal pressure chamber 3.

[0034] The transformer chamber sealing ring 13 adopts a silicone sealing ring. The transformer chamber sealing ring 13 is composed of an upper transformer chamber sealing ring that matches the top shell edge of the transformer chamber 4 and a lower transformer chamber sealing ring that matches the inner wall of the transformer chamber 4. The upper transformer chamber sealing ring and the lower transformer chamber sealing ring are integrally formed. The lower transformer chamber sealing ring is placed in the transformer chamber 4 and fits the inner wall of the transformer chamber 4. The upper transformer chamber sealing ring is fixed to the top of the transformer chamber 4 and fits the top shell edge of the transformer chamber 4.

[0035] The transformer cavity 4 is also fixed with a transformer cavity temperature and humidity sensor and a transformer cavity pressure sensor (not shown in the figure). The transformer cavity pressure sensor is a HP206C pressure sensor. The temperature and humidity detection uses a digital temperature and humidity sensor AHTM10. The temperature and humidity sensor uses CMOS technology and SMD packaging, which is more compact and saves a lot of space for the layout of other devices in the design.

[0036] The oxygen concentration sensor 19 is an electrochemical sensor, and the differential pressure sensor 18 is of the MCP-H20 type.

[0037] The cavity inside the oxygen detection device is mainly composed of two parts: a closed normal pressure cavity 3 without gas exchange and a variable pressure cavity 4 with gas exchange. The closed normal pressure cavity 3 without gas exchange is equipped with circuit components such as a battery 10, a control circuit board 11, and an antenna 12. Through a closed assembly method, it is always in a normal pressure environment without voltage changes, which greatly reduces the requirements for components and ensures reliability. The variable pressure cavity 4 with gas exchange will be connected to the sampling pipeline (the air intake pipeline of the closed-circuit submersible breathing apparatus) to maintain the same air pressure as the closed-circuit submersible breathing apparatus. The oxygen concentration sensor 19, the differential pressure sensor 18, the temperature and humidity sensor, and the absolute pressure sensor are deployed in the cavity. All components in this part will meet the conditions of withstanding 7 bar atmospheric pressure.

[0038] The first waterproof shell 1: The material is PA66, which is corrosion-resistant and has good mechanical strength. There is no large cavity or space inside to withstand high pressure underwater. The interface part is fully sealed using multiple sealing methods such as silicone pads and adhesives.

[0039] The placement of each sensor needs to take into account the influence of fluid mechanics. Since the oxygen detection device is located on the air intake pipe, gas flows inside the oxygen detection device when the human body inhales. The air pressure is unstable at this time, and the reading of the oxygen concentration sensor will fluctuate due to changes in air pressure. This is not an ideal state for detecting oxygen concentration. Therefore, the differential pressure sensor 18 is sampled at the gas inlet and outlet of the oxygen detection device. At this time, the differential pressure sensor 18 can detect the air pressure difference to further reflect whether the gas is flowing through, and can reflect the size of the air flow. In order to enhance the strength of the differential pressure signal, the air inlet sampling tube should face the incoming air direction to increase the intake pressure, and the air outlet sampling tube should face the outlet air direction to reduce the outlet air pressure, which can increase the signal response.

[0040] The oxygen concentration sensor 19, the transformer chamber temperature and humidity sensor, and the transformer chamber pressure sensor should try to avoid fluctuations caused by pressure, so they can be placed perpendicular to the airflow direction to keep the gas stable, which is conducive to obtaining stable values.

[0041] The transmission of antenna 12 needs to consider the influence of electromagnetic shielding. At this time, certain requirements are put forward for the material selection of internal components, and non-metallic materials that have no effect on electromagnetics should be used as much as possible; the control circuit board should be well protected against electromagnetic radiation, and the communication cables should be laid to avoid being close to the antenna and running parallel to the antenna; if necessary, a shielding layer can be added to the cable to prevent mutual interference with the antenna.

[0042] The control button 7 needs to be a dedicated underwater button that can meet the requirements of high pressure and seawater corrosion. The function of the button is to adjust the mode, such as the frequency of sending data, starting on land, etc.

[0043] like Figure 5 As shown, a power management circuit, a main control circuit, a signal conditioning circuit, an ADC circuit, an IIC interface and a wireless transmission circuit are arranged on the control circuit board. The battery (such as a lithium battery) is electrically connected to the main control circuit through the power management circuit, the oxygen concentration sensor is electrically connected to the ADC circuit through the signal conditioning circuit, the differential pressure sensor is electrically connected to the ADC circuit, the transformer cavity temperature and humidity sensor and the transformer cavity pressure sensor are electrically connected to the main control circuit through the IIC interface, the ADC circuit, the IIC interface, the control button, the indicator light and the wireless transmission circuit are electrically connected to the main control circuit, and the wireless transmission circuit is electrically connected to the wireless radio frequency receiving module through the antenna.

[0044] The control button 7 and the indicator light 8 satisfy the simple functions of human-computer interaction. The complex functions need to be set up after the oxygen display device is paired with the oxygen detection device or configured through the charging communication interface. The charging communication interface can satisfy the wired charging function, and can also perform program refresh, data reading, function configuration, etc.

[0045] During onshore calibration, the top of the contact 9 is electrically connected to an external test fixture, and the display of the test fixture communicates bidirectionally with the main control circuit through the contact 9. The test fixture calibrates the oxygen sensor over the entire range in combination with standard gases of multiple concentrations.

[0046] like Figure 6 As shown, the oxygen display device includes a second waterproof shell 20 with a hollow inner cavity, a display 21 is embedded in the second waterproof shell 20, a wireless radio frequency receiving module, a power supply, a power management module and a main microcontroller are arranged in the second waterproof shell 20, the wireless radio frequency receiving module and the display are electrically connected to the main microcontroller, and the power supply is electrically connected to the main microcontroller through the power management module.

[0047] The second waterproof housing 20 is made of a combination of aluminum and non-metallic materials, which can meet the requirements of high strength and achieve wireless communication.

[0048] The following is a detailed introduction to the working principle of the dual-chamber underwater wireless data monitoring system for diving respirators:

[0049] The main control circuit is used to enter a low power consumption state upon receiving a long press signal of the control button 7. At this time, the pressure value of the transformer chamber pressure sensor is continuously read through the IIC interface to determine whether the diver has entered the water. When the pressure value reaches the set water entry pressure value, it is determined that the diver has entered the water. At this time, the oxygen concentration sensor 19, the differential pressure sensor 18, the transformer chamber temperature and humidity sensor, the antenna 12, etc. start to work, and the oxygen detection device enters a normal working state until it detects that the pressure value of the transformer chamber pressure sensor is at normal pressure, that is, the oxygen detection device is out of water, then it exits the normal working state and enters a low power consumption state; or, the main control circuit is used to enter a low power consumption state upon receiving a long press signal of the control button 7, and then when a double-click signal of the control button 7 is received, the oxygen detection device enters a normal working state until it detects that the pressure value of the transformer chamber pressure sensor is at normal pressure, that is, the oxygen detection device is out of water, then it exits the normal working state and enters a low power consumption state.

[0050] The pressure difference sensor 18 is used to detect the pressure difference signal between the intake gas inflow joint 16 and the intake gas outflow joint 15, and the ADC circuit is used to convert the pressure difference signal into digital form and transmit it to the main control circuit.

[0051] The oxygen concentration sensor 19 is used to detect the oxygen concentration signal in the transformer chamber 4, the signal conditioning circuit is used to filter, impedance match and amplify the oxygen concentration signal, and the ADC circuit is used to convert the conditioned oxygen concentration signal into digital form and transmit it to the main control circuit.

[0052] The transformer cavity temperature and humidity sensor is used to detect the temperature and humidity in the transformer cavity 4 and transmit it to the main control circuit through the IIC interface.

[0053] The main control circuit is used to analyze the diver's exhalation using a closed-circuit diving breathing apparatus based on the pressure difference signal (when there is a pressure difference, it indicates that the diver is inhaling using a closed-circuit diving breathing apparatus, and when there is no pressure difference, it indicates that the diver is exhaling using a closed-circuit diving breathing apparatus), receive the oxygen concentration signal and perform temperature, humidity and pressure compensation on the oxygen concentration signal, perform digital-to-analog conversion on the compensated oxygen concentration signal, and send it through the antenna after signal amplification by the wireless transmission circuit.

[0054] The main microcontroller is used to receive the oxygen concentration value through the wireless radio frequency receiving module and display it through the display 21.

[0055] The power management circuit is used to provide supply voltages of +12V, VCC5V and VCC 3.3V.

[0056] The frequency bands of radio frequency communication are similar. When multiple pairs of communication devices coexist at close range (within 2m), the problem of crosstalk will occur. In order to solve the problem of crosstalk, the oxygen detection device sets the wireless transmission time interval through the program, that is, sends communication data at random time intervals to reduce the collision probability of wireless data. The specific implementation method is: the main control circuit is used to set the wireless transmission time interval T = (Tc+1)*N, where N is a random integer from 1 to (1 / f1-1 / f2)*10, Tc is the transmission duration of each data link containing oxygen concentration sent wirelessly, T and Tc are both in ms, f1 Hz~f2 Hz is the update frequency, and the wireless transmission time interval T is updated in a random number manner after each data link is sent.

[0057] For example: the time interval is stored in a variable T. After each data link is sent, the variable T is updated with a random number. In order to meet the update frequency of 0.1Hz to 2Hz, that is, the effective data sending interval is 0.5s to 10s, the random time interval range is set to 500ms to 10000ms, and the variable T is updated every time it is sent. In this way, the sending time of each data link is uncertain.

[0058] If two devices transmit at the same time, and the duration of each data link transmission is 99msTc, that is, the data adjustable range is 9500ms (10000ms-500ms), if the random transmission time of the two devices is guaranteed not to cross within 100ms (99ms+1), then the random time interval T=100*n=(Tc+1)*n, where n is a random coefficient (an integer between 0 and 95 does not include 0), so the probability of data synchronization of the two devices at one time is (1 / 95)2, which is about 0.01%. Therefore, through this design, the data transmission time of the two devices is unlikely to cause conflict, greatly reducing the problem of data collision of multiple pairs of communication devices at close range.

[0059] Different oxygen detection devices are set with different communication addresses. The oxygen display device performs ID matching before receiving the data sent by the oxygen detection device. The data link with incorrect matching will not process the data, that is, filter out useless information to prevent data information update errors. Wireless communication is susceptible to environmental interference and is not as stable and reliable as wired communication data. In order to ensure the correct transmission of data payload content, some anti-interference measures need to be taken. The wireless communication of this system is transmitted in an open space, so it is impossible to use hardware measures such as adding shielding to carry out anti-interference design. It can only be achieved through software. Specifically, a cyclic redundancy check code (CRC) check is used. All the data content sent is calculated by CRC to obtain a check code, which is sent out as the tail frame of each message. After receiving the information, the oxygen display device uses the same CRC calculation method to calculate the data. If the calculation results are inconsistent, it means that the data link has been interfered with and the data has been damaged, and the processing of the message can be abandoned.

[0060] Specifically, the main control circuit is also used to configure a unique communication address for the oxygen detection device, and each data link sent wirelessly contains a unique communication address and a CRC check code calculated using a set CRC calculation method; the main microcontroller is used to receive a data link containing an oxygen concentration value, match the stored communication address with the communication address in the received data link, and calculate the CRC check code using a set CRC calculation method, and match the newly calculated CRC check code with the CRC check code in the received data link; when the communication address and the CRC check code are successfully matched, the oxygen concentration value in the received data link is displayed on the display.

[0061] like Figure 7As shown, the main control circuit includes a microcontroller chip U5 of the GD32F103 model. The main control circuit mainly realizes functions such as sensor signal acquisition, power switching, indicator light control, concentration signal calculation and compensation processing, and signal output. The VBAT pin (pin 1) of the microcontroller chip U5 is connected to the power supply voltage VCC3.3V of the power management circuit and is also grounded through a capacitor C9. The NRST pin (pin 7) of the microcontroller chip U5 is connected to the power supply voltage VCC3.3V through a pull-up resistor R5 and is also grounded through a capacitor C6. The VDDA pin (pin 13) of the microcontroller chip U5 is connected to the power supply voltage VCC3.3V. The VSS pin (pin 18) of the microcontroller chip U5 is connected to the power supply voltage VCC3.3V through a capacitor C18, and the VDD pin (pin 19) is connected to the power supply. Voltage VCC3.3V, PC0 pin (pin 8) and PC1 pin (pin 9) of microcontroller U5 are connected to control button, PC2 pin (pin 10) and PC3 pin (pin 11) of microcontroller U5 are connected to indicator light, PA1 pin (pin 15) of microcontroller U5 is connected to IIC interface for receiving pressure signal, PA10 pin (pin 43) and PA11 pin (pin 44) of microcontroller U5 are connected to IIC interface for receiving temperature and humidity signal, PA2 (pin 16) of microcontroller U5 is connected to The ADC circuit is used to receive the oxygen concentration signal and the pressure difference signal. The VSS pin (pin 31) of the microcontroller chip U5 is connected to the VDD pin (pin 32) through the capacitor C21. The VSS pin (pin 63) of the microcontroller chip U5 is connected to the power supply voltage VCC3.3V through the capacitor C10. The VDD pin (pin 64) is connected to the power supply voltage VCC3.3V. The BOOT0 pin (pin 60) of the microcontroller chip U5 is grounded through the resistor R8. The VSS pin (pin 47) of the microcontroller chip U5 is connected to the power supply voltage VC through the capacitor C17. C3.3V and VDD pins (pin 48) are connected to the power supply voltage VCC3.3V, the PD0 pin (pin 5) and PD1 pin (pin 6) of the microcontroller U5 are connected to the crystal oscillator circuit, the NRST pin (pin 7), SWDIO pin (pin 46) and SWCLK pin (pin 49) of the microcontroller U5 are connected to the program download interface J1, and the PC5 pin (pin 25), PB0 pin (pin 26), PB1 pin (pin 27) and PB2 pin (pin 28) of the microcontroller U5 are all connected to the wireless transmitting circuit.

[0062] like Figure 8As shown, the wireless transmitting circuit includes: the S1 pin (pin 1) of the MOS tube U3 is grounded, the G1 pin (pin 2) is connected to the PB0 pin (pin 26) of the microcontroller chip U5, the S2 pin (pin 3) is connected to the power supply voltage +12V of the power management circuit, the G2 pin (pin 4) is connected to the PC5 pin (pin 25) of the microcontroller chip U5, the anode of the protection diode D1 is grounded, the cathode of the protection diode D1 is connected to the anode of the protection diode D2, the cathode of the protection diode D2 is connected to the power supply voltage +12V, the two D1 pins (pin 7 and pin 8) and the two D2 pins (pin 5 and pin 6) of the MOS tube U3 are all connected between the cathode of the protection diode D1 and the anode of the protection diode D2, and one end of the resistor R1, the resistor R2, the resistor R3 and the resistor R4 are all connected to the cathode of the protection diode D1 and the anode of the protection diode D2. The anode of the protection diode D3 is connected to the ground, the cathode of the protection diode D3 is connected to the anode of the protection diode D4, and the cathode of the protection diode D4 is connected to the power supply voltage +12V. The two D1 pins (pin 7 and pin 8) and the two D2 pins (pin 5 and pin 6) of the MOS tube U4 are connected between the cathode of the protection diode D3 and the anode of the protection diode D4 and are connected to the RF antenna terminal A2.

[0063] In the wireless transmitting circuit, A2 is the RF antenna terminal, which is convenient for replacing and repairing wires; D1-D4 are Schottky protection diodes to prevent circuit overvoltage and ensure the stability, high quality and high efficiency of the signal transmission process; MOS tube IRF7389 is used as a transmitting dual driver to amplify the power of the RF signal to an appropriate level to ensure that the signal strength is maintained during the transmission process; resistors R1-R4 ensure that the output impedance of the transmitting circuit matches the input impedance of the antenna or transmission medium to maximize the transmission of signal energy.

[0064] like Fig. 9As shown, the signal conditioning circuit includes: the positive input terminal (pin 3) of the operational amplifier U5A is connected to the positive terminal of the oxygen concentration sensor through a resistor R28, the negative input terminal (pin 2) of the operational amplifier is connected to the negative terminal of the oxygen concentration sensor through a resistor R27, the negative input terminal (pin 2) of the operational amplifier is connected to the output terminal (pin 1) of the operational amplifier through a resistor R21, the resistor R21 is connected in parallel with the capacitor C24, the output terminal (pin 1) of the operational amplifier is connected to the ADC circuit through a resistor R33, the negative terminal (pin 4) of the chip power supply of the operational amplifier is connected to the ADC circuit through a capacitor C32, the negative terminal (pin 4) of the chip power supply of the operational amplifier is connected to the negative terminal of the oxygen concentration sensor and is also directly grounded, the positive terminal (pin 8) of the chip power supply of the operational amplifier is connected in parallel with capacitors C22 and C23, one end of the capacitor C22 and the capacitor C23 are connected to the power supply voltage VCC3.3V, and the other end is grounded.

[0065] Since the signal of the oxygen concentration sensor is a relatively weak voltage signal, it needs to be amplified before data acquisition can be performed. The oxygen concentration sensor signal does not involve negative signals, so the operational amplifier AD8522 is powered by a single power supply. The oxygen concentration sensor signal is amplified by about 40 times through the operational amplifier and the amplifier resistor R21 to achieve an oxygen concentration sensor signal voltage output range of 0 to 3.3V, which improves the accuracy of the signal and realizes the full range of signal acquisition. Finally, it is sent to the ADC circuit after RC filtering.

[0066] like Fig.10 As shown, the power management circuit includes: the VIN pin (pin 3) of the voltage regulator chip U1 (AMS1117-5.0) is connected to the positive end of the lithium battery A1 and is also grounded through the capacitor C1. The positive end of the lithium battery A1 outputs a power supply voltage of +12V and the negative end is grounded. The GND pin (pin 1) of the voltage regulator chip U1 is grounded. The VOUT pin (pin 2) of the voltage regulator chip U1 is connected to the VIN pin (pin 3) of the voltage regulator chip U2 (AMS1117-3.3) and is also grounded through the capacitor C2. The VOUT pin (pin 2) of the voltage regulator chip U1 outputs a power supply voltage VCC5V. The VIN pin (pin 3) of the voltage regulator chip U2 is grounded through the capacitor C3. The GND pin (pin 1) of the voltage regulator chip U2 is grounded. The VOUT pin (pin 2) of the voltage regulator chip U2 is grounded through the capacitor C4. The VOUT pin (pin 2) of the voltage regulator chip U23 outputs a power supply voltage VCC3.3V.

[0067] The DC 12V power supply in the power management circuit is provided by a lithium battery, which is used by AMS1117-5.0 to achieve a 5V voltage output, and then provided to AMS1117-3.3 to achieve a 3.3V voltage output after capacitor decoupling and filtering, and then powered the main control circuit, etc.

[0068] The 12V power supply voltage powers the wireless transmission circuit and the 5V voltage regulator chip U1, the 5V power supply voltage mainly powers the 3.3V voltage regulator chip U2, and the 3.3V power supply voltage mainly powers the main control circuit and the sensor.

[0069] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that these are only examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A dual-chamber underwater wireless data monitoring system for a submersible breathing apparatus, characterized in that: It includes a gas detection device and a gas display device, the gas detection device includes a first waterproof shell with a hollow inner cavity, a waterproof baffle is fixed in the first waterproof shell, so that the hollow inner cavity of the first waterproof shell is divided by the waterproof baffle into a closed normal pressure chamber without gas exchange and a variable pressure chamber with gas exchange, which are separated on the left and right, a normal pressure chamber sealing ring and a normal pressure chamber upper cover are fixed in sequence on the top of the first waterproof shell and located directly above the closed normal pressure chamber, a control button is embedded on the normal pressure chamber upper cover, a battery, a control circuit board and an antenna are fixed in the closed normal pressure chamber, and a normal pressure chamber sealing ring and a normal pressure chamber upper cover are fixed on the top of the first waterproof shell and located directly above the closed normal pressure chamber. A transformer chamber sealing ring and a transformer chamber upper cover are fixed on the upper part in sequence; an inhalation gas outflow joint for connecting the upper inhalation pipeline of a closed submersible breathing apparatus is fixedly provided on the front side of the transformer chamber upper cover; an inhalation gas inflow joint for connecting the lower inhalation pipeline of a closed submersible breathing apparatus is fixedly provided on the front side of the bottom shell of the first waterproof shell and located directly below the transformer chamber; a mounting plate is fixedly provided in the transformer chamber near the position where the inhalation gas inflow joint is installed; a differential pressure sensor and a gas concentration sensor are fixedly provided on the mounting plate; and the control button, the differential pressure sensor, the gas concentration sensor, the antenna and the battery are all electrically connected to the control circuit board; The gas display device comprises a second waterproof shell with a hollow inner cavity, a display is embedded in the second waterproof shell, a wireless radio frequency receiving module, a power supply, a power management module and a main microcontroller are arranged in the second waterproof shell, the wireless radio frequency receiving module and the display are electrically connected to the main microcontroller, and the power supply is electrically connected to the main microcontroller through the power management module; The control circuit board is used to enter a working state upon receiving a start signal from a control button, receive a pressure difference between an inhalation gas inflow joint and an inhalation gas outflow joint detected by a pressure difference sensor, indicate that a diver is inhaling using a closed-circuit submersible breathing apparatus when a pressure difference exists, and indicate that a diver is exhaling using a closed-circuit submersible breathing apparatus when no pressure difference exists, and when the diver is exhaling using a closed-circuit submersible breathing apparatus based on the pressure difference value of the pressure difference sensor, receive a gas concentration value detected by a gas concentration sensor and send it out through an antenna; The main microcontroller is used to receive the gas concentration value through the wireless radio frequency receiving module and display it through the display.

2. The dual-chamber underwater wireless data monitoring system for a scuba diving apparatus as claimed in claim 1, characterized in that: A transformer cavity temperature and humidity sensor and a transformer cavity pressure sensor are also fixed in the transformer cavity. A power management circuit, a main control circuit, a signal conditioning circuit, an ADC circuit, an IIC interface and a wireless transmission circuit are arranged on the control circuit board. The battery is electrically connected to the main control circuit through the power management circuit, the gas concentration sensor is electrically connected to the ADC circuit through the signal conditioning circuit, the differential pressure sensor is electrically connected to the ADC circuit, the transformer cavity temperature and humidity sensor and the transformer cavity pressure sensor are both electrically connected to the main control circuit through the IIC interface, the ADC circuit, the IIC interface, the control button, the indicator light and the wireless transmission circuit are all electrically connected to the main control circuit, and the wireless transmission circuit is electrically connected to the wireless radio frequency receiving module through the antenna; The main control circuit is used to enter a low power consumption state upon receiving a long press signal of the control button. At this time, the pressure value of the transformer chamber pressure sensor is continuously read through the IIC interface to determine whether the diver has entered the water. When the pressure value reaches the water entry set pressure value, it is determined that the diver has entered the water. At this time, the gas concentration sensor, the differential pressure sensor, the transformer chamber temperature and humidity sensor, and the antenna start to work, and the gas detection device enters a normal working state until it detects that the pressure value of the transformer chamber pressure sensor is at normal pressure, that is, the gas detection device is out of water, then exits the normal working state and enters a low power consumption state; or, the main control circuit is used to enter a low power consumption state upon receiving a long press signal of the control button, and then when a double-click signal of the control button is received, the gas detection device enters a normal working state until it detects that the pressure value of the transformer chamber pressure sensor is at normal pressure, that is, the gas detection device is out of water, then exits the normal working state and enters a low power consumption state; The differential pressure sensor is used to detect the differential pressure signal between the inhaled gas inflow joint and the inhaled gas outflow joint, and the ADC circuit is used to convert the differential pressure signal into digital form and transmit it to the main control circuit; The gas concentration sensor is used to detect the gas concentration signal in the transformer cavity, the signal conditioning circuit is used to filter, impedance match and amplify the gas concentration signal, and the ADC circuit is used to convert the conditioned gas concentration signal into digital form and transmit it to the main control circuit; The transformer cavity temperature and humidity sensor is used to detect the temperature and humidity in the transformer cavity and transmit it to the main control circuit via the IIC interface; The main control circuit is used to analyze the diver's exhalation using a closed-circuit diving breathing apparatus based on the pressure difference signal, receive the gas concentration signal and perform temperature, humidity and pressure compensation on the gas concentration signal, perform digital-to-analog conversion on the compensated gas concentration signal and send it through the antenna after amplification by the wireless transmission circuit signal; The power management circuit is used to provide supply voltages of +12V, VCC5V and VCC 3.3V.

3. The dual-chamber underwater wireless data monitoring system for a scuba diving apparatus as claimed in claim 2, characterized in that: The main control circuit is used to set the wireless transmission time interval T=(Tc+1)*N, where N is a random integer from 1 to (1 / f1-1 / f2)*10, Tc is the transmission duration of each data link containing gas concentration transmitted wirelessly, T and Tc are both in ms, f1 Hz~f2 Hz is the update frequency, and the wireless transmission time interval T is updated in a random number manner after each data link is sent; The main control circuit is also used to configure a unique communication address for the gas detection device, and each data link sent wirelessly includes a unique communication address and a CRC check code calculated using a set CRC calculation method; The main microcontroller is used to receive a data link containing a gas concentration value, match the stored communication address with the communication address in the received data link, calculate a CRC check code using a set CRC calculation method, and match the newly calculated CRC check code with the CRC check code in the received data link; when the communication address and the CRC check code are successfully matched, the gas concentration value in the received data link is displayed on a display.

4. The dual-chamber underwater wireless data monitoring system for a scuba diving apparatus as claimed in claim 2, characterized in that: The main control circuit includes a microcontroller chip U5 of model GD32F103, wherein the VBAT pin of the microcontroller chip U5 is connected to the power supply voltage VCC3.3V of the power management circuit and is also grounded through a capacitor C9, the NRST pin of the microcontroller chip U5 is connected to the power supply voltage VCC3.3V through a pull-up resistor R5 and is also grounded through a capacitor C6, the VDDA pin of the microcontroller chip U5 is connected to the power supply voltage VCC3.3V, the VSS pin of the microcontroller chip U5, i.e. the 18th pin, is connected to the power supply voltage VCC3.3V through a capacitor C18, and the VDD pin, i.e. the 19th pin, is connected to the power supply voltage VCC3.3V, the PC0 pin and the PC1 pin of the microcontroller chip U5 are connected to a control button, the PC2 pin and the PC3 pin of the microcontroller chip U5 are connected to an indicator light, the PA1 pin of the microcontroller chip U5 is connected to an IIC interface for receiving a pressure signal, and the PA10 pin and the PA11 pin of the microcontroller chip U5 are connected to an IIC interface for receiving a temperature and humidity signal. degree signal, the PA2 pin of the microcontroller U5 is connected to the ADC circuit, the VSS pin of the microcontroller U5, i.e. the 31st pin, is connected to the VDD pin, i.e. the 32nd pin, through the capacitor C21, the VSS pin of the microcontroller U5, i.e. the 63rd pin, is connected to the power supply voltage VCC3.3V through the capacitor C10, and the VDD pin, i.e. the 64th pin, is connected to the power supply voltage VCC3.3V, the BOOT0 pin of the microcontroller U5 is grounded through the resistor R8, the VSS pin of the microcontroller U5, i.e. the 47th pin, is connected to the power supply voltage VCC3.3V through the capacitor C17, and the VDD pin, i.e. the 48th pin, is connected to the power supply voltage VCC3.3V, the PD0 pin and PD1 pin of the microcontroller U5 are connected to the crystal oscillator circuit, the NRST pin, SWDIO pin and SWCLK pin of the microcontroller U5 are connected to the program download interface J1, and the PC5 pin, PB0 pin, PB1 pin and PB2 pin of the microcontroller U5 are all connected to the wireless transmitting circuit.

5. The dual-chamber underwater wireless data monitoring system for a scuba diving apparatus as claimed in claim 4, characterized in that: The wireless transmitting circuit comprises: the S1 pin of the MOS tube U3 is grounded, the G1 pin is connected to the PB0 pin of the microcontroller chip U5, the S2 pin is connected to the power supply voltage +12V of the power management circuit, the G2 pin is connected to the PC5 pin of the microcontroller chip U5, the anode of the protection diode D1 is grounded, the cathode is connected to the anode of the protection diode D2, the cathode of the protection diode D2 is connected to the power supply voltage +12V, the two D1 pins and the two D2 pins of the MOS tube U3 are connected between the cathode of the protection diode D1 and the anode of the protection diode D2, and one end of the resistor R1, the resistor R2, the resistor R3 and the resistor R4 are connected to the cathode of the protection diode D1 and the anode of the protection diode D2. The other ends of the resistors R1, R2, R3 and R4 are connected to the RF antenna terminal A2; the S1 pin of the MOS tube U4 is grounded, the G1 pin is connected to the PB2 pin of the microcontroller chip U5, the S2 pin is connected to the power supply voltage +12V, the G2 pin is connected to the PB1 pin of the microcontroller chip U5, the anode of the protection diode D3 is grounded, the cathode is connected to the anode of the protection diode D4, the cathode of the protection diode D4 is connected to the power supply voltage +12V, the two D1 pins and the two D2 pins of the MOS tube U4 are connected between the cathode of the protection diode D3 and the anode of the protection diode D4 and are connected to the RF antenna terminal A2.

6. The dual-chamber underwater wireless data monitoring system for a scuba diving apparatus as claimed in claim 2, characterized in that: The signal conditioning circuit includes: the positive input terminal of the operational amplifier is connected to the positive terminal of the gas concentration sensor through a resistor R28, the negative input terminal of the operational amplifier is connected to the negative terminal of the gas concentration sensor through a resistor R27, the negative input terminal of the operational amplifier is connected to the output terminal of the operational amplifier through a resistor R21, the resistor R21 is connected in parallel with the capacitor C24, the output terminal of the operational amplifier is connected to the ADC circuit through a resistor R33, the negative terminal of the chip power supply of the operational amplifier is connected to the ADC circuit through a capacitor C32, the negative terminal of the chip power supply of the operational amplifier is connected to the negative terminal of the gas concentration sensor and is also directly grounded, the positive terminal of the chip power supply of the operational amplifier is connected in parallel with capacitors C22 and C23, one end of the capacitor C22 and the capacitor C23 is connected to a power supply voltage VCC3.3V, and the other end is grounded.

7. The dual-chamber underwater wireless data monitoring system for a scuba diving apparatus as claimed in claim 2, characterized in that: The power management circuit includes: the VIN pin of the voltage regulator chip U1 is connected to the positive end of the lithium battery A1 and is also grounded through the capacitor C1, the positive end of the lithium battery A1 outputs a power supply voltage of +12V, and the negative end is grounded, the GND pin of the voltage regulator chip U1 is grounded, the VOUT pin of the voltage regulator chip U1 is connected to the VIN pin of the voltage regulator chip U2 and is also grounded through the capacitor C2, the VOUT pin of the voltage regulator chip U1 outputs a power supply voltage VCC5V, the VIN pin of the voltage regulator chip U2 is grounded through the capacitor C3, the GND pin of the voltage regulator chip U2 is grounded, the VOUT pin of the voltage regulator chip U2 is grounded through the capacitor C4, and the VOUT pin of the voltage regulator chip U23 outputs a power supply voltage VCC3.3V.

8. The dual-chamber underwater wireless data monitoring system for a scuba diving apparatus as claimed in claim 2, characterized in that: An indicator light is embedded on the upper cover of the normal pressure chamber, and the indicator light is electrically connected to the main control circuit.

9. The dual-chamber underwater wireless data monitoring system for a scuba diving apparatus as claimed in claim 2, characterized in that: A contact is embedded on the upper cover of the normal pressure chamber, and the bottom end of the contact is electrically connected to the main control circuit; During onshore calibration, the top of the contact is electrically connected to an external test fixture, the display of the test fixture communicates bidirectionally with the main control circuit via the contact, and the test fixture calibrates the gas sensor over the entire range in combination with standard gases of multiple concentrations.

10. The dual-chamber underwater wireless data monitoring system for a scuba diving apparatus as claimed in claim 1, characterized in that: The normal pressure chamber sealing ring adopts a silicone sealing ring, and the normal pressure chamber sealing ring is composed of a normal pressure chamber upper sealing ring matching the edge of the top shell of the closed normal pressure chamber and a normal pressure chamber lower sealing ring matching the inner wall of the closed normal pressure chamber. The normal pressure chamber upper sealing ring and the normal pressure chamber lower sealing ring are integrally formed, the normal pressure chamber lower sealing ring is placed in the closed normal pressure chamber and fits the inner wall of the closed normal pressure chamber, and the normal pressure chamber upper sealing ring is fixed on the top of the closed normal pressure chamber and fits the edge of the top shell of the closed normal pressure chamber; The transformer chamber sealing ring adopts a silicone sealing ring, and the transformer chamber sealing ring is composed of an upper transformer chamber sealing ring matching the top shell edge of the transformer chamber and a lower transformer chamber sealing ring matching the inner wall of the transformer chamber. The upper transformer chamber sealing ring and the lower transformer chamber sealing ring are integrally formed, the lower transformer chamber sealing ring is placed in the transformer chamber and fits the inner wall of the transformer chamber, and the upper transformer chamber sealing ring is fixed on the top of the transformer chamber and fits the top shell edge of the transformer chamber.

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