Multi-principle redundant water depth pressure sensor

Abstract

The invention, which relates to the technical field of the pressure sensor, discloses a multi-principle redundant water depth pressure sensor comprising a pressure sensing probe, a circuit box and a cable. Signal crosslinking is realized between the pressure sensing probe and the circuit box through a cable; the pressure sensing probe is arranged outside the cabin body to sense a water depth pressure signal, and the circuit box is arranged inside the cabin body to complete signal processing and sending; the pressure sensing probe is integrated with three pressure measuring channels including a diaphragm capsule diaphragm pressure switch, a shallow water pressure measuring sensor and a deep water pressure measuring sensor; an MCU, a power module, an acquisition driving module, a bus communication module and embedded software are integrated in the circuit box, and measured water depth pressure signals are transmitted to a thunder operation electronic device in three modes of analog signals, TTL switch signals and serial bus signals. The invention solves the problem that the prior art cannot quickly meet the requirements of the system for improving the precision and reliability of the sensor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure sensors, in particular to a multi-principle redundant water depth pressure sensor. BACKGROUND

[0002] With the continuous improvement of the intelligence degree of weapon equipment, higher precision and reliability requirements are put forward for sensors as the system / device neural sensing unit, and more complex environmental adaptability requirements. However, due to the limitation of the current domestic basic research, the precision and reliability improvement technology of the sensitive element is very difficult to realize, and the realization cycle is very long, which cannot quickly meet the system's demand for improving the precision and reliability of the sensor. Therefore, while continuously researching the basic technology, it is necessary to innovatively use more system components and arrangement schemes to improve the reliability and environmental applicability of the sensor in use, and use rich compensation and correction schemes to improve the overall precision of the sensor in use. SUMMARY

[0003] In view of the above problems in the prior art, the multi-principle redundant water depth pressure sensor provided by the present application solves the problem that the prior art cannot quickly meet the system's demand for improving the precision and reliability of the sensor.

[0004] In order to achieve the above-mentioned application purpose, the technical scheme adopted by the present application is as follows: a multi-principle redundant water depth pressure sensor, comprising a pressure sensing probe, a circuit box and a cable; The pressure sensing probe and the circuit box are connected through the cable to realize signal crosslinking. The pressure sensing probe is arranged outside the cabin body to sense the water depth pressure signal, and the circuit box is arranged inside the cabin body to complete signal processing and transmission. The pressure sensing probe integrates a diaphragm capsule pressure switch, a shallow water pressure measurement sensor and a deep water pressure measurement sensor three pressure measurement channels. The diaphragm capsule pressure switch adopts a diaphragm capsule pressure measurement principle, and the shallow water pressure measurement sensor and the deep water pressure measurement sensor adopt a silicon piezoresistive pressure measurement principle. The circuit box is integrated with an MCU, a power module, an acquisition driving module, a bus communication module and embedded software. The measured water depth pressure signal is transmitted to the radar warning electronic device in the form of analog signal, TTL switch signal and serial bus signal.

[0005] Further, the power module converts the 28V voltage provided by the radar warning electronic device into +13.75V, +5V and +3.3V stabilized power supply, which supplies power to the internal circuit of the pressure sensing probe and the circuit box. The acquisition driving module analyzes and follows the conversion of the water depth analog signal output by the pressure sensing probe, and provides the converted signal to the MCU. The MCU and the solver program solve the collected water depth simulation signals, and then output TTL switch signals required by the radar operating electronic device to the radar operating electronic device through a TTL driving circuit. The bus communication module realizes real-time bus communication between the circuit box and the radar operating electronic device.

[0006] Further, the embedded software adopts a three-layer hierarchical architecture, including a driving layer, an intermediate layer and an application layer; the driving layer completes driving functions of an internal ADC module, a USART module, a CAN control module and a general I / O module of the MCU; the application layer completes logical solving and communication control functions; and the intermediate layer provides an interactive interface for the driving layer and the application layer.

[0007] Further, the driving layer provides driving for the ADC module, the USART module, the CAN control module and the general I / O module of the MCU to realize A / D conversion function, I / O driving function, RS-232 bus communication function and CAN bus communication function. The intermediate layer is designed with an initialization interface program, an A / D interface program, a bus program and global variables; the initialization interface program realizes configuration functions of the application layer initialization to the bottom layer hardware resources; the A / D interface program realizes A / D conversion function by calling the bottom layer A / D hardware driving program through the A / D sampling solving program of the application layer; the bus program realizes bus communication function by calling the USART driving program and the CAN driving program through the communication control program of the application layer; and the global variables realize switch signal output function by calling the general I / O driving program through the 5-way switch solving program of the application layer.

[0008] Further, the application layer completes: power-on initialization: the power-on initialization completes CPU initialization, USART initialization, AD initialization, CAN initialization, interrupt initialization, WDT initialization, timer initialization, GPIO initialization and global variable initialization; power-on self-test: the power-on self-test completes internal and external power supply inspection, signal input inspection, output inspection and memory inspection on the board level, and stores all self-test results in a specified memory address; input solving: the input solving collects shallow water pressure and deep water depth pressure sensor voltage signals and performs A / D conversion, receives software version reading instructions, 5-way switch threshold setting and reading instructions of the radar operating electronic device, and receives inquiry start and stop instructions; parameter solving: the parameter solving compares shallow water pressure values and deep water pressure values with 5-way switch setting values, and controls 5-way switch values according to the comparison results; Output solution: the output solution outputs 5-way switch value according to parameter solution result, sends water depth pressure sensor software version, 5-way switch setting value and setting value out-of-range information, sends shallow water voltage value, deep water voltage value and 5-way switch state value.

[0009] Further, the input solution takes the average value of 10 times of sampling in each sampling period when processing A / D conversion data, removes the data with deviation greater than or equal to 20 mV from the average value, and then takes the average value of the remaining data, if the collected data all have deviation greater than or equal to 20 mV from the average value, then the average value of 10 times of sampling data is directly taken, and the final obtained average value is subjected to α filtering, and the α value is 0.125, and the first period is not subjected to α filtering.

[0010] Further, when controlling 5-way switch value, if the value calculated by the A / D conversion formula of the shallow water pressure digital signal in 8 consecutive periods is greater than the super shallow depth setting value, then the I / O port PB5 is set to low level, otherwise it is set to high level. If the value calculated by the A / D conversion formula of the shallow water pressure digital signal in 8 consecutive periods is greater than the upper limit of inflation setting value, then the I / O port PB8 is set to high level, otherwise it is set to low level. If the value calculated by the A / D conversion formula of the shallow water pressure digital signal in 8 consecutive periods is greater than the lower limit of inflation setting value, then the I / O port PB9 is set to high level, otherwise it is set to low level. If the value calculated by the A / D conversion formula of the deep water pressure digital signal in 8 consecutive periods is greater than the lower limit of depth setting value, then the I / O port PB6 is set to high level, otherwise it is set to low level. If the value calculated by the A / D conversion formula of the deep water pressure digital signal in 8 consecutive periods is greater than the super deep depth setting value, then the I / O port PB7 is set to high level, otherwise it is set to low level.

[0011] Further, the embedded software is also designed with an A / D calibration program, which can only be periodically called within 10s of power-on initialization; the A / D calibration program can analyze the host computer control instructions to determine whether to enter calibration mode, collect the set sampling voltage value and correct the ADC conversion coefficient according to the set calibration formula, output the A / D converter conversion value, sampling voltage value and calibration channel number for the host computer to confirm, and call the initialization program soft reset; The embedded software has a factory calibration mode and a normal working mode, within 10s after completing power-on initialization and power-on self-test, the factory calibration mode is entered according to the host computer bus calibration instruction, the software is reset after completing calibration, and the sensor enters the normal working mode.

[0012] Further, the pressure sensing probe shell is made of stainless steel material, and the surface of the pressure sensing probe shell is passivated; the pressure sensing probe is filled with oil medium, and the pressure transmission is realized by pushing the oil medium by air or seawater, and the oil medium is used to isolate the seawater from the pressure sensing probe.

[0013] Further, the circuit box structure is made of aluminum alloy material, and the surface of the circuit box structure is anodized; the circuit box connector and the cover plate are sealed by using conductive rubber pads, so that a sealed structure is formed in the circuit box; the surface of the printed circuit board in the circuit box is sprayed with TS96-11 polyurethane varnish, and the printed circuit board is installed in the sealed structure.

[0014] The beneficial effects of the present application are: Multi-channel integration: The pressure sensing probe integrates the membrane switch of the membrane box, the shallow water pressure measurement sensor, and the deep water pressure measurement sensor into three pressure measurement channels, realizing the integration of the pressure measurement channels.

[0015] Multi-signal redundancy: The circuit box transmits the measured water depth pressure signals in three ways, namely analog signals, TTL switch signals, and serial bus signals, to the radar operating electronic device, wherein the bus signals use RS-232 and CAN bus communication forms. The multi-path redundancy of the signals is realized, ensuring the reliability of the system.

[0016] Lightweight and small size: The water depth pressure sensor integrates all the pressure measurement units in the pressure sensing probe, completes the conversion, correction compensation, analog output, and switch output of the pressure signal, and transmits the analog voltage signal to the circuit box for operation processing and reporting, realizing the small size design of the pressure sensing probe. The circuit box of the water depth pressure sensor is made of aluminum alloy material with surface anodization, realizing lightweight design under the premise of meeting the use requirements.

[0017] High precision: The pressure signal of the water depth pressure sensor is compensated and corrected by a special processing chip, and the full-temperature comprehensive accuracy is ±0.25% FS.

[0018] High reliability: The mature design scheme and process scheme of our factory are used, and after simplified design, derating design, electromagnetic protection design, corrosion protection design, and environmental adaptability design, the product reliability is better than the product demand.

[0019] Resistant to complex environment: After environmental adaptability design, the water depth pressure sensor can withstand high temperature, low temperature, and humid heat in natural environment, and can withstand vibration and impact in mechanical environment.

[0020] Corrosion resistance: The pressure sensing probe shell is made of stainless steel material and is passivated on the surface; the circuit box is made of aluminum alloy material and is anodized on the surface. The product has good corrosion resistance.

[0021] Electromagnetic compatibility: adopt the design of full sealing, high and low frequency signal filtering, and can withstand complex electromagnetic environment.

[0022] National production: the selected components, raw materials and standard parts are 100% domestic. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a system principle block diagram.

[0024] Figure 2 It is a water depth pressure sensor external cross-link diagram.

[0025] Figure 3 It is a water depth pressure sensor function architecture diagram.

[0026] Figure 4 It is a circuit box principle block diagram.

[0027] Figure 5 It is a water depth pressure sensor software overall logic block diagram.

[0028] Figure 6 It is a water depth pressure sensor software layered architecture diagram.

[0029] Figure 7 It is a water depth pressure sensor software external interface diagram.

[0030] Figure 8 It is a water depth pressure sensor software internal interface diagram.

[0031] Figure 9 It is a water depth pressure sensor software function structure diagram. DETAILED DESCRIPTION

[0032] The application will be further described below in combination with the drawings and specific embodiments.

[0033] The traditional sensor is a pressure sensitive unit and a signal correction processing unit integrated together. Its shortcomings are limited by the use conditions of electronic components in the signal processing unit, limiting the environmental adaptability of the sensor, and in addition, because the sensing unit needs to measure the physical signal amount, its environment is relatively harsh, which leads to the reliability of the integrated sensor to be reduced because the signal processing unit works in a relatively harsh environment.

[0034] Therefore, the present application separates the pressure sensing unit and the signal correction processing unit, encloses the sensing unit in the pressure sensing probe to realize the sensing of the physical signal to the electrical signal, and transmits the signal to the signal processing unit through the cable. The signal processing unit is enclosed in the signal processing circuit box to complete the signal correction compensation and calculation, and then transmits the processed signal to the upper system through the cable. The signal processing unit which has poor environmental adaptability is far away from the signal sensing unit in the harsh environment, so that the reliability of the signal processing unit is improved, and the overall reliability of the sensor is improved.

[0035] As shown in Figures 1-3 a multi-principle redundant water depth pressure sensor, comprising a pressure sensing probe, a circuit box and a cable; The pressure sensing probe and the circuit box realize signal crosslinking through the cable; the pressure sensing probe is arranged outside the cabin body to sense the water depth pressure signal, and the circuit box is arranged inside the cabin body to complete signal processing and transmission; The pressure sensing probe integrates a diaphragm capsule pressure switch, a shallow water pressure measurement sensor and a deep water pressure measurement sensor, the diaphragm capsule pressure switch adopts a diaphragm capsule pressure measurement principle, and the shallow water pressure measurement sensor and the deep water pressure measurement sensor adopt a silicon piezoresistive pressure measurement principle; The diaphragm capsule sensor mainly comprises a sensing element combination and a switch seat combination; the diaphragm in the sensing element combination senses the change of pressure, generates displacement, drives the push rod to move up and down, and the top rod drives the spring in the switch seat combination to make the micro switch in the switch seat combination turn on or off; when the pressure rises above the set working pressure point, the micro switch is turned on; when the pressure drops below the set working pressure point, the micro switch is turned off.

[0036] The sensitive element of the silicon piezoresistive sensor is a silicon piezoresistive core made of the piezoresistive effect of single crystal silicon material. The silicon piezoresistive pressure sensitive element is a group of pressure sensitive resistors and a Wheatstone bridge connected by a semiconductor planar process method on a specific crystal face of single crystal silicon. When the silicon diaphragm is subjected to a pressure signal, the resistance value of one pair of bridge arms increases, and the resistance value of the other pair of bridge arms decreases accordingly, and the change in resistance value is proportional to the pressure.

[0037] When the bridge is supplied with an excitation current, the size of the resistance value change can be converted into a voltage signal, and the output voltage is proportional to the pressure, thereby realizing the purpose of measuring the pressure.

[0038] The output signal of the silicon piezoresistive core is a weak signal of 0mV-120mV, and with the change of temperature, the zero output signal and the sensitivity output signal will drift with the change of temperature, so that the signal conditioning circuit is required to amplify and correct the temperature error of the output signal of the silicon piezoresistive core to realize the required output range and precision of the voltage signal.

[0039] The circuit box integrates MCU, power module, acquisition driving module, bus communication module and embedded software, and transmits the measured water depth pressure signal to the radar warning electronic device in analog signal, TTL switch signal and serial bus signal.

[0040] The circuit box of the water depth pressure sensor has power conversion, signal acquisition, logic calculation, TTL switch level output and bus communication functions, as shown in Figure 4 The main working principle is as follows: a) The power module converts the 28V voltage provided by the radar warning electronic device into +13.75V, +5V and +3.3V stabilized power supply, which powers the pressure probe and the internal circuit of the circuit box; b) The acquisition driving module analyzes and follows the conversion of the water depth analog signal output by the pressure probe, and provides the converted signal to the MCU; c) The MCU and the calculation program calculate the acquired water depth analog signal, and output the TTL switch signal required by the radar warning electronic device to the radar warning electronic device through the TTL driving circuit; d) The bus communication module realizes real-time bus communication between the circuit box and the radar warning electronic device.

[0041] The water depth pressure sensor uses embedded program, does not use operating system, and does not use database. The overall algorithm logic is that the product software completes power-on initialization, enters power-on self-test, and after passing the self-test, periodically calls the calibration program and the calculation program. The overall logic diagram of the software is shown in Figure 5 .

[0042] The embedded software adopts a three-layer hierarchical architecture, including a driving layer, an intermediate layer and an application layer; the driving layer completes the driving functions of the MCU internal ADC module, USART module, CAN control module and general I / O module; the application layer completes the logic calculation and communication control functions; the intermediate layer can provide an interactive interface for the driving layer and the application layer. The software architecture is shown in Figure 6 .

[0043] The driving layer provides driving for the ADC module, USART module, CAN control module and general I / O module in the MCU chip to realize A / D conversion function, I / O driving function, RS-232 bus communication function and CAN bus communication function. The external interface of the water depth pressure sensor software is shown in Figure 7 .

[0044] Based on the interaction requirements of the driving layer software and the application layer software. The intermediate layer is designed with initialization interface program, A / D interface program, bus program and global variables. The initialization interface program realizes the configuration function of the application layer initialization to the underlying hardware resources. The A / D interface program realizes the A / D sampling solution program calling the underlying A / D hardware driver program to complete the A / D conversion function. The bus program realizes the communication control program calling the underlying USART driver program and CAN driver program to complete the bus communication function. The global variables realize the 5-way switch solution program calling the underlying general I / O driver program to realize the switch signal output function. The software internal interface of the water depth pressure sensor is as shown in Figure 8 .

[0045] The software of the water depth pressure sensor is an important part of the water depth pressure sensor and runs on the hardware platform of the water depth pressure sensor. The application layer software of the water depth pressure sensor completes the functions required by the product. As shown in Figure 9 , according to the product functions, the application layer software needs to complete: a) Power-on initialization: the power-on initialization completes CPU initialization, USART initialization, AD initialization, CAN initialization, interrupt initialization, WDT initialization, timer initialization, GPIO initialization, and global variable initialization; b) Power-on self-test: the power-on self-test completes the board-level internal and external power supply inspection (AD sampling voltage and limit value comparison to determine the power supply state), signal input inspection (inspection of whether the sampling is within the specified range of analog quantity), output inspection (driven output circuit works, and the output signal is sampled to make a judgment), memory inspection (five-way pressure set value reading and inspection), and stores all self-test results in the specified memory address; The specific design is as follows: After completing the initialization, it automatically enters the power-on self-test process, reads the set value stored in the Flash through the internal bus, and performs validity detection; Compare the test point detection data with the stored set value to determine whether the monitoring point is abnormal; To increase reliability, the data stored in each Flash is read three times to determine that the set value is read correctly; To avoid fault misreporting, the data of the acquisition test point is filtered by α, and compared with the set value three times to determine the detection state.

[0046] c) Input solution: the input solution collects the shallow water pressure and deep water depth pressure sensor voltage signals and performs A / D conversion, receives the software version reading instruction of the radar electronic device, 5-way switch threshold setting and reading instruction, and receives inquiry start and stop instructions; For the input RS-232 bus data, CAN bus data, because the data has been MCU on-chip USART module, CAN module according to the corresponding bus standards to complete the processing, so the software does not need to handle. But only complete A / D conversion data need each program cycle on A / D conversion input data smoothing filter processing, processing method as follows: Each sampling period sampling 10 times and take the average, remove the data from the average deviation greater than or equal to 20 mV data after the remaining data take the average, if the data collected from the average deviation greater than or equal to 20 mV, then directly on the 10 sampling data take the average, on the final average α filter, α value of 0.125, and the first cycle does not carry out α filter.

[0047] d) parameter solution: the parameter solution of the water depth pressure sensor compares the shallow water pressure value and the deep water pressure value with the 5-way switch setting value, and controls the 5-way switch value according to the comparison result; The parameter solution software of the water depth pressure sensor completes the communication parameter solution according to the respective bus communication protocol by reading and writing the corresponding on-chip register for RS-232 bus data and CAN bus data, and then calls the interface function to call the underlying driver program to complete the bus communication. According to the following determination logic, the A / D conversion value is used to control the output TTL level signal, and the specific logic is as follows: The shallow water pressure digital signal collected is calculated by the A / D conversion formula, compared with the ultra-shallow depth setting value, the inflation upper limit depth setting value and the inflation lower limit depth setting value, and the ultra-shallow depth (initially set to high level), the inflation upper limit depth (initially set to low level) and the inflation lower limit depth (initially set to low level) TTL switch value control signals are controlled according to the following logic.

[0048] 1) If the value calculated by the A / D conversion formula of the shallow water pressure digital signal of the continuous 8 cycles is greater than the ultra-shallow depth setting value, then the I / O port PB5 is low, otherwise it is high; 2) If the value calculated by the A / D conversion formula of the shallow water pressure digital signal of the continuous 8 cycles is greater than the inflation upper limit setting value, then the I / O port PB8 is high, otherwise it is low; 3) If the value calculated by the A / D conversion formula of the shallow water pressure digital signal of the continuous 8 cycles is greater than the inflation lower limit setting value, then the I / O port PB9 is high, otherwise it is low.

[0049] The deep water pressure digital signal collected by the deep water pressure sensor is calculated by the A / D conversion formula, compared with the lower limit depth setting value and the ultra-deep depth setting value, and the lower limit depth (initially set to low level) and the ultra-deep depth (initially set to low level) TTL switch value control signals are controlled according to the following logic.

[0050] 1) If the value calculated by the A / D conversion formula of the deep water pressure digital signal for 8 continuous periods is greater than the lower limit depth setting value, then the I / O port PB6 is set to high level, otherwise it is set to low level; 2) If the value calculated by the A / D conversion formula of the deep water pressure digital signal for 8 continuous periods is greater than the super deep depth setting value, then the I / O port PB7 is set to high level, otherwise it is set to low level.

[0051] e) Output solution: the output solution outputs 5-way switch quantity according to the parameter solution result, sends the water depth pressure sensor software version, 5-way switch setting value and setting value out-of-range information, sends the shallow water voltage value, deep water voltage value and 5-way switch state value.

[0052] The RS-232 bus data and CAN bus data output by the water depth pressure sensor do not need to be processed on the software, because the data has been processed by the USART module and CAN module in the MCU according to the corresponding bus standards. The I / O port level signal output has been processed by the general I / O processing module, so it does not need to be processed on the software.

[0053] RS-232 and CAN bus data receiving: compare the A / D sampling value with the five-way switch setting value to judge the correctness of the RS-232 bus input setting value, and periodically output the 5-way switch level signal; respond to the RS-232 and CAN bus input to perform RS-232 and CAN bus output.

[0054] In addition, in order to improve the A / D conversion accuracy, the embedded software also has an A / D calibration program, which can only be called periodically within 10s of power-on initialization. The A / D calibration program can analyze the host computer control command to determine whether to enter the calibration mode, collect the set sampling voltage value and correct the ADC conversion coefficient according to the set calibration formula, output the A / D converter conversion value, sampling voltage value and calibration channel number for the host computer to confirm, and call the initialization program for software reset; In order to avoid calling the factory calibration program, the embedded software has a factory calibration mode and a normal working mode. Within 10s after power-on initialization and power-on self-test, the factory calibration mode is entered according to the host computer bus calibration instruction, the software is reset after calibration, and the sensor enters the normal working mode.

[0055] In an embodiment of the present application, the pressure sensing probe shell is made of stainless steel material, and the surface of the pressure sensing probe shell is passivated; the pressure sensing probe is sealed with oil medium, and the pressure transmission is realized by pushing the oil medium through air or seawater, and the seawater is isolated from the pressure sensing probe by using the oil medium.

[0056] The circuit box structure is made of aluminum alloy material, and the surface of the circuit box structure is subjected to anodic oxidation treatment, so as to realize lightweight design under the premise of meeting the use requirements; the circuit box connector and the cover plate are mounted by using conductive rubber pads for sealing, so as to form a sealed structure inside the circuit box; the surface of the printed circuit board in the circuit box is sprayed with TS96-11 polyurethane varnish, and the printed circuit board is mounted in the sealed structure.

[0057] In order to improve system reliability, the traditional single series model is optimized to a series-parallel combined model by a redundancy scheme. A diaphragm film type pressure sensitive element and two silicon piezoresistive pressure sensitive elements are integrated in a sensing unit (pressure probe) to measure water depth pressure. In a signal processing unit, a deep water pressure mechanical switch signal is provided outside through a mechanical signal relay module, a deep water pressure analog signal is provided outside after signal correction and compensation through an analog signal processing module, and a water pressure signal and a Bit check signal are provided outside through a signal acquisition module, a central processing unit, a dispersion program and an interface circuit.

[0058] In addition, in order to adapt to the demand of system for improving the accuracy of sensor, the performance index of sensitive element is continuously strengthened, such as lower hysteresis, nonlinearity, temperature drift, higher repeatability and stability. However, due to the late start of domestic research on sensitive element compared with foreign countries, and the relatively weak basic research on materials, basic process and high-end equipment, it is difficult to improve the performance index of sensitive element, and it takes a long time and high cost to improve the performance index.

[0059] Based on the current situation, in order to realize the high precision demand to the maximum extent, and combined with the fact that the final accuracy of sensor is determined by the index and accuracy regulation scheme of sensitive element, the single sensitive element characteristic index scheme is changed to a comprehensive regulation scheme to improve the final use accuracy of sensor. In this scheme, the following methods are used to improve the comprehensive accuracy: Multiple principles are used to collect the same pressure source from the sensitive elements of the channels, and the signals of each channel are cross-checked (mainly providing repeatability and stability); signal conditioning circuit is used to compensate and correct the signals of the sensitive elements (mainly compensating temperature drift); central processor is used to combine with calculation program for software fine adjustment (mainly correcting nonlinearity, repeatability, etc.); Bit check module is used to combine with calculation program for signal monitoring and correction.

[0060] In order to adapt to the marine environment requirements of water depth pressure sensor, when designing the product, the ability of the product to resist humidity, heat, mold, salt spray and acidic atmosphere is mainly considered, and the product is designed from the following aspects: The water depth pressure sensor structure is made of 06Cr19Ni10 stainless steel material which is resistant to moisture, heat, mold, salt mist and acidic atmosphere, and the surface is passivated to improve the material's resistance to marine environment. The water depth pressure sensor is connected by laser welding, and the connector is sealed by conductive rubber pad to form a sealed structure inside the sensor, which can effectively prevent the influence of moisture, heat, salt mist and mold on the product. The circuit box is made of aluminum alloy material, and the surface is anodized to improve the material's resistance to moisture, heat, mold, salt mist and acidic atmosphere. The circuit box connector and cover are sealed by conductive rubber pad to form a sealed structure inside the circuit box, which can effectively prevent the influence of moisture, heat, salt mist and mold on the product. The screws used on the product are made of stainless steel (06Cr19Ni10), and the surface treatment is stainless steel passivation, which can meet the requirements of moisture, heat, mold, salt mist and acidic atmosphere. The connector is made of aluminum alloy material, and the surface is nickel plated, which can meet the requirements of moisture, heat, mold, salt mist and acidic atmosphere. The printed circuit board is sprayed with TS96-11 polyurethane varnish, and the circuit board has good moisture, heat, mold, salt mist and acidic atmosphere performance. At the same time, the printed circuit board is installed in a sealed structure, which can meet the requirements of moisture, heat, mold, salt mist and acidic atmosphere performance.

[0061] To make the sensor's measuring medium compatible with air and seawater medium, an oil medium is sealed inside the pressure sensing probe, and air / seawater is used to push the oil medium to realize pressure transmission. At the same time, the oil medium is used to isolate seawater and the pressure sensing probe to avoid the influence of seawater or marine microorganisms on the sensitive probe, thereby realizing the improvement of medium compatibility at the lowest cost.

[0062] Those skilled in the art will appreciate that the embodiments described herein are presented for the purpose of helping the reader understand the principles of the present application, and should be understood as not limiting the scope of protection of the present application to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations according to the technical inspiration disclosed in the present application without departing from the essence of the present application, and these modifications and combinations are still within the scope of protection of the present application.

Claims

1. A multi-principle redundant water depth pressure sensor, characterized in that, The pressure sensor probe, the circuit box and the cable are included. The pressure sensor probe and the circuit box are connected by the cable, the pressure sensor probe is arranged outside the cabin to sense the water depth pressure signal, and the circuit box is arranged inside the cabin to complete signal processing and transmission. The pressure sensor probe integrates a diaphragm pressure switch, a shallow water pressure measuring sensor and a deep water pressure measuring sensor, the diaphragm pressure switch adopts a diaphragm pressure measuring principle, and the shallow water pressure measuring sensor and the deep water pressure measuring sensor adopt a silicon piezoresistance pressure measuring principle. The circuit box integrates an MCU, a power module, an acquisition driving module, a bus communication module and embedded software, and transmits the measured water depth pressure signal to the radar warning electronic device in the form of an analog signal, a TTL switch signal and a serial bus signal.

2. The multi-principle redundant water depth pressure sensor of claim 1, wherein, The power module converts the 28V voltage provided by the radar warning electronic device into +13.75V, +5V and +3.3V stable voltage sources to supply power to the pressure sensor probe and the internal circuit of the circuit box. The acquisition driving module analyzes and follows the conversion of the water depth analog signal output by the pressure sensor probe and provides the converted signal to the MCU. The MCU and the calculation program calculate the acquired water depth analog signal and output the TTL switch signal required by the radar warning electronic device to the radar warning electronic device through a TTL driving circuit. The bus communication module realizes real-time bus communication between the circuit box and the radar warning electronic device.

3. The multi-principle redundant water depth pressure sensor of claim 1, wherein, The embedded software adopts a three-layer hierarchical architecture, including a driving layer, an intermediate layer and an application layer; the driving layer completes the driving functions of the internal ADC module, USART module, CAN control module and general I / O module of the MCU; the application layer completes the logical calculation and communication control functions; and the intermediate layer provides an interactive interface for the driving layer and the application layer.

4. The multi-principle redundant water depth pressure sensor of claim 3, wherein, The driving layer provides driving for the ADC module, USART module, CAN control module and general I / O module of the MCU to realize A / D conversion function, I / O driving function, RS-232 bus communication function and CAN bus communication function. The intermediate layer is designed with an initialization interface program, an A / D interface program, a bus program and global variables; the initialization interface program realizes the configuration function of the application layer initialization to the underlying hardware resources; the A / D interface program realizes the A / D conversion function by calling the A / D hardware driving program of the underlying layer through the A / D sampling calculation program of the application layer; the bus program realizes the bus communication function by calling the USART driving program and CAN driving program of the underlying layer through the communication control program of the application layer; and the global variables realize the switch signal output function by calling the general I / O driving program of the underlying layer through the 5-way switch calculation program of the application layer.

5. The multi-principle redundant water depth pressure sensor of claim 3, wherein, The application layer completes: power-on initialization, CPU initialization, USART initialization, AD initialization, CAN initialization, interrupt initialization, WDT initialization, timer initialization, GPIO initialization and global variable initialization. Power-on self-test: the power-on self-test completes the internal and external power supply inspection, signal input inspection, output inspection, memory inspection in the board level, and stores all self-test results in the specified memory address; Input solution: the input solution collects the shallow water pressure and deep water depth pressure sensor voltage signals and performs A / D conversion, receives the software version reading instruction of the anti-radar electronic device, 5-way switch threshold setting and reading instruction, and receives the inquiry start and stop instructions; Parameter solution: the parameter solution compares the shallow water pressure value and the deep water pressure value with the 5-way switch setting value, and controls the 5-way switch value according to the comparison result; Output solution: the output solution outputs the 5-way switch value according to the parameter solution result, sends the water depth pressure sensor software version, 5-way switch setting value and setting value out-of-range information, and sends the shallow water voltage value, deep water voltage value and 5-way switch state value.

6. The multi-principle redundant water depth pressure sensor of claim 5, wherein, When processing the A / D conversion data, the input solution samples 10 times per sampling period and takes the average value, removes the data with a deviation of greater than or equal to 20 mV from the average value, and then takes the average value of the remaining data. If the collected data all have a deviation of greater than or equal to 20 mV from the average value, the average value of the 10 sampling data is directly taken, and the final obtained average value is subjected to α filtering, with the α value being 0.125, and the first period not being subjected to α filtering.

7. The multi-principle redundant water depth pressure sensor of claim 5, wherein, When controlling the 5-way switch value, if the value calculated by the A / D conversion formula of the shallow water pressure digital signal in 8 consecutive periods is greater than the shallow depth setting value, the I / O port PB5 is set to low level, otherwise it is set to high level; If the value calculated by the A / D conversion formula of the shallow water pressure digital signal in 8 consecutive periods is greater than the inflation upper limit setting value, the I / O port PB8 is set to high level, otherwise it is set to low level; If the value calculated by the A / D conversion formula of the shallow water pressure digital signal in 8 consecutive periods is greater than the inflation lower limit setting value, the I / O port PB9 is set to high level, otherwise it is set to low level; If the value calculated by the A / D conversion formula of the deep water pressure digital signal in 8 consecutive periods is greater than the lower limit depth setting value, the I / O port PB6 is set to high level, otherwise it is set to low level; If the value calculated by the A / D conversion formula of the deep water pressure digital signal in 8 consecutive periods is greater than the super deep depth setting value, the I / O port PB7 is set to high level, otherwise it is set to low level.

8. The multi-principle redundant water depth pressure sensor of claim 5, wherein, The embedded software is also designed with an A / D calibration program, which can only be periodically called within 10s of power-on initialization; the A / D calibration program can analyze the host computer control instructions to determine whether to enter the calibration mode, collect the set sampling voltage value and correct the ADC conversion coefficient according to the set calibration formula, output the A / D converter conversion value, sampling voltage value and calibration channel number for the host computer to confirm, and call the initialization program for software reset; The embedded software has a factory calibration mode and a normal working mode. Within 10s after completing power-on initialization and power-on self-test, the factory calibration mode is entered according to the host computer bus calibration instruction, the software is reset after completing the calibration, and the sensor enters the normal working mode.

9. The multi-principle redundant water depth pressure sensor of claim 1, wherein, The pressure sensing probe shell is made of stainless steel material, and the surface of the pressure sensing probe shell is passivated; the pressure sensing probe is sealed with oil medium, and the pressure transmission is realized by pushing the oil medium through air or seawater, and the oil medium is used to isolate the seawater and the pressure sensing probe.

10. The multi-principle redundant water depth pressure sensor of claim 1, wherein, The circuit box structure is made of aluminum alloy material, and the surface of the circuit box structure is anodized; the circuit box connector and the cover plate are sealed by using conductive rubber pads, so that a sealed structure is formed in the circuit box; the surface of the printed circuit board in the circuit box is sprayed with TS96-11 polyurethane varnish, and the printed circuit board is installed in the sealed structure.

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