Multi-source heterogeneous pressure sensing system, self-calibration method and aircraft

Abstract

The invention provides a multi-source heterogeneous pressure sensing system, a self-calibration method and an aircraft, the system comprises a silicon resonance unit, one or more silicon piezoresistive units, a gas circuit control module, a temperature control module, an external gas source and an information processing circuit, and the information processing circuit comprises a self-calibration unit. The self-calibration unit is respectively connected with the programmed switch, the information acquisition unit, the temperature control module and an external gas source, and is used for controlling all valves to be opened when a regular maintenance instruction is not received and a preset time is not reached, performing power-on zero-position self-calibration on a measurement signal of the silicon piezoresistive meter core by taking the measurement signal of the silicon resonance meter core as a reference, or else, performing power-on zero-position self-calibration on the measurement signal of the silicon piezoresistive meter core by taking the measurement signal of the silicon resonance meter core as a reference. And adjusting to a plurality of preset temperature points through the temperature control module, adjusting to a plurality of preset pressure points by taking a measurement signal of the silicon resonance meter core as a reference, and obtaining a measurement signal of the silicon piezoresistive meter core so as to carry out calibration parameter self-calibration. According to the technical scheme, the technical problem that in the prior art, a multi-source heterogeneous system cannot be calibrated and maintained online is solved.

Description

Technical Field

[0001] The present invention relates to the field of pressure sensing technology, and in particular to a multi-source heterogeneous pressure sensing system, a self-calibration method and an aircraft. Background Art

[0002] In the field of pressure sensing technology, a multi-source heterogeneous system refers to a system-level device composed of pressure sensing components of different principles, structures, and data types. Through the hybrid integration of heterogeneous pressure sensing structures and multi-source data fusion processing, a cost-effective, multi-pressure channel collaborative measurement function is achieved. Compared with a single-principle pressure sensing system, it has greater advantages in terms of comprehensive performance indicators such as volume, weight, and cost.

[0003] New weapons and equipment have put forward high-performance, low-cost and miniaturized coupling requirements for multi-channel atmospheric sensing systems. At present, in order to achieve high-performance design, atmospheric sensing systems generally use high-performance vibration tubes and silicon resonant pressure sensor integrated designs to ensure pressure measurement accuracy, thereby obtaining high-precision atmospheric parameters. However, although vibration tubes and silicon resonant pressure sensors have high accuracy, they are expensive and bulky, which leads to high cost and large volume of multi-channel atmospheric sensing systems, which cannot meet the needs of new weapons and equipment. To this end, the present invention considers using resonant and piezoresistive pressure sensors to form a multi-source heterogeneous system, using the resonant pressure sensor as the reference source of other piezoresistive pressure sensors to achieve calibration and correction functions, effectively reducing the volume, weight and cost relative to the full resonant system, and effectively improving the performance indicators such as accuracy and stability relative to the full piezoresistive system.

[0004] However, multi-source heterogeneous systems involve multiple types and numbers of pressure sensor devices. During the application of the system, low-precision devices often have problems such as temperature drift, time drift and environmental impact, which will have a great impact on the performance stability of the system in long-term applications, seriously restricting its application scope. In order to improve the performance stability of the system and maintain performance, multi-source heterogeneous systems often undergo regular calibration and maintenance. The routine operation is to remove them from the application scenario and return them to the factory, and place them in a constant temperature environment such as an incubator and connect an external gas source to perform relevant calibration tests, parameter calculations and updates. The more sensors there are, the more complex their operations are and the lower their work efficiency is. Therefore, the problem of how to achieve convenient online calibration and maintenance of multi-source heterogeneous systems and improve work efficiency also needs to be solved. Summary of the invention

[0005] The present invention provides a multi-source heterogeneous pressure sensing system, a self-calibration method and an aircraft, which can solve the technical problem in the prior art that the multi-source heterogeneous system cannot be calibrated and maintained online.

[0006] According to one aspect of the present invention, a multi-source heterogeneous pressure sensing system is provided, the system comprising: A silicon resonance unit, wherein the silicon resonance unit comprises a silicon resonance core, a support structure, a resonance control module and a first gas path shielding integrated structure. The support structure and the resonance control module are designed as an integrated whole. The silicon resonance core is arranged on the support structure and connected to the resonance control module. The first gas path shielding integrated structure is a metal cover. A sealing cover of the first gas path shielding integrated structure is arranged on the silicon resonance core, the support structure and the resonance control module. The first gas path shielding integrated structure has a first gas nozzle for communicating with a first channel to be measured. The first gas path shielding integrated structure is also used for electromagnetic shielding. One or more silicon piezoresistive units, each of which includes more than two silicon piezoresistive cores, a piezoresistive conditioning module and a second gas path shielding integrated structure, the silicon piezoresistive core is connected to the piezoresistive conditioning module, the second gas path shielding integrated structure is a metal cover, a sealing cover of the second gas path shielding integrated structure is provided on the silicon piezoresistive core and the piezoresistive conditioning module, the second gas path shielding integrated structure has a second gas nozzle for communicating with a second channel to be measured, and the second gas path shielding integrated structure is also used for electromagnetic shielding; An air path control module, the air path control module includes a valve and a program-controlled switch matched with the valve, the first air path shielding integrated structure and the second air path shielding integrated structure and the plurality of second air path shielding integrated structures are connected by the valve, and the opening and closing of the valve is controlled by the program-controlled switch; A temperature control module, which is arranged on the silicon resonance unit and the silicon piezoresistive unit; An external gas source, the external gas source is used to communicate with the first channel to be measured and the second channel to be measured when performing self-calibration of calibration parameters; An information processing circuit, the information processing circuit includes a preprocessing unit, an information acquisition unit and a self-calibration unit, the preprocessing unit is respectively connected to the resonance control module and the piezoresistive conditioning module, and is used to preprocess the measurement signals output by the resonance control module and the piezoresistive conditioning module, and the information acquisition unit is connected to the preprocessing unit, and is used to acquire the preprocessed measurement signals; The self-calibration unit is respectively connected to the program-controlled switch, the information acquisition unit, the temperature control module and the external gas source. The self-calibration unit is used to control all valves to open through the program-controlled switch when no regular maintenance instruction is received and the preset time is not reached, obtain the measurement signals of the silicon resonant meter core and the silicon piezoresistive meter core through the information acquisition unit, and perform power-on zero position self-calibration on the measurement signal of the silicon piezoresistive meter core based on the measurement signal of the silicon resonant meter core, and control all valves to close through the program-controlled switch after the power-on zero position self-calibration. The self-calibration unit is also used to adjust the temperature to multiple preset temperature points through the temperature control module when a regular maintenance instruction is received or the preset time is reached, and at each preset temperature point, adjust the pressure to multiple preset pressure points through the external gas source based on the measurement signal of the silicon resonant meter core as a reference, and obtain the measurement signal of the silicon piezoresistive meter core through the information acquisition unit to perform self-calibration of calibration parameters.

[0007] Furthermore, the measuring ranges of the multiple silicon piezoresistive cores in the same silicon piezoresistive unit are different.

[0008] According to another aspect of the present invention, a self-calibration method for the multi-source heterogeneous pressure sensing system provided by the present invention is provided, and the method comprises: S1, connecting an external gas source to the first channel to be tested and the second channel to be tested; S2, the system is powered on and completes initialization and self-test; S3, determining whether a regular maintenance instruction has been received or a preset time has been reached, if not, proceeding to S4, if yes, proceeding to S5; S4, control all valves to open through program-controlled switches, obtain measurement signals of the silicon resonant meter core and the silicon piezoresistive meter core through the information acquisition unit, perform power-on zero position self-calibration on the measurement signal of the silicon resonant meter core based on the measurement signal of the silicon piezoresistive meter core, and control all valves to close through program-controlled switches after power-on zero position self-calibration; S5, adjust the temperature to multiple preset temperature points through the temperature control module, at each preset temperature point, adjust the pressure to multiple preset pressure points through an external gas source based on the measurement signal of the silicon resonant meter core, and obtain the measurement signal of the silicon piezoresistive meter core through the information acquisition unit to perform self-calibration of calibration parameters.

[0009] Furthermore, when performing power-on zero position self-calibration, the pressure difference between the first channel to be measured and the second channel to be measured is adjusted by a plug and / or a pressure regulating gas source so that the pressure difference is no greater than half of the accuracy requirement of the multi-source heterogeneous pressure sensing system.

[0010] Furthermore, the measurement signal of the silicon resonant meter core is used as a reference, and the power-on zero position self-calibration of the measurement signal of the silicon piezoresistive meter core includes: Obtaining measurement signals of the silicon resonant meter core and each silicon piezoresistive meter core within a preset time period; Calculate the measurement difference between the measurement signal of each silicon piezoresistive meter core and the measurement signal of the silicon resonant meter core at the corresponding measurement time; Calculate the average value of the measured difference for each silicon piezoresistive meter core; The average value of the measured difference corresponding to each silicon piezoresistive core is used for power-on zero position self-calibration.

[0011] Furthermore, obtaining the measurement signal of the silicon piezoresistive meter core through the information acquisition unit to perform self-calibration of the calibration parameters includes: for each silicon piezoresistive meter core, fitting its measurement signal to obtain calibration parameters, and updating the calibration parameters.

[0012] Furthermore, a 5th-order pressure-6th-order temperature fitting model is used when fitting the measurement signal of each silicon piezoresistive core.

[0013] According to yet another aspect of the present invention, an aircraft is provided. The aircraft includes the multi-source heterogeneous pressure sensing system proposed in the present invention.

[0014] By applying the technical solution of the present invention, a multi-source heterogeneous pressure sensing system, a self-calibration method and an aircraft are provided. The system is based on the existing silicon resonant core and silicon piezoresistive core, and the two cores are innovatively mixed and integrated to form a multi-channel multi-source heterogeneous pressure sensing system. The core-level integration is combined with the multi-core information integration processing. Compared with the multi-sensor level integration, the space occupied by the sensor housing, sensor circuit, internal gap of the sensor and gap between large-size sensors is reduced. Multiple cores can be integrated in the circuit in a matrix manner, which greatly reduces the volume of the system. The high precision and high stability of the silicon resonant core are utilized, and the silicon resonant core is used as the pressure reference. By cooperating with an external gas source, a temperature control module and combining algorithms such as data correction and compensation, regular online calibration and maintenance of the silicon piezoresistive core without disassembly and assembly can be realized, the calibration process and equipment configuration are simplified, and the work efficiency is effectively improved. Compared with the use of silicon resonant cores for all channels, the volume, weight and cost can be effectively reduced. Compared with the use of silicon piezoresistive cores for all channels, the measurement accuracy and stability can be effectively improved. This multi-source heterogeneous pressure sensing system significantly improves the performance of the silicon piezoresistive core measurement channel while using only one high-precision, high-stability silicon resonant core, and realizes high-precision, high-reliability, miniaturized, and low-cost measurement of multi-channel pressure. It is simple and practical, easy and effective to implement, and has strong feasibility. It can meet the coupling requirements of new weapons and equipment for atmospheric sensing systems in terms of high performance, low cost, and miniaturization, can effectively improve the performance stability of the system in long-term applications, and realize convenient online calibration and maintenance of the system, which can expand the application field of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A schematic flow chart of a multi-source heterogeneous pressure sensing system self-calibration method provided according to a specific embodiment of the present invention is shown. DETAILED DESCRIPTION

[0017] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions 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 only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0019] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0020] According to a specific embodiment of the present invention, a multi-source heterogeneous pressure sensing system is provided, the system comprising: A silicon resonance unit, wherein the silicon resonance unit comprises a silicon resonance core, a support structure, a resonance control module and a first gas path shielding integrated structure. The support structure and the resonance control module are designed as an integrated whole. The silicon resonance core is arranged on the support structure and connected to the resonance control module. The first gas path shielding integrated structure is a metal cover. A sealing cover of the first gas path shielding integrated structure is arranged on the silicon resonance core, the support structure and the resonance control module. The first gas path shielding integrated structure has a first gas nozzle for communicating with a first channel to be measured. The first gas path shielding integrated structure is also used for electromagnetic shielding. One or more silicon piezoresistive units, each of which includes more than two silicon piezoresistive cores, a piezoresistive conditioning module and a second gas path shielding integrated structure, the silicon piezoresistive core is connected to the piezoresistive conditioning module, the second gas path shielding integrated structure is a metal cover, a sealing cover of the second gas path shielding integrated structure is provided on the silicon piezoresistive core and the piezoresistive conditioning module, the second gas path shielding integrated structure has a second gas nozzle for communicating with a second channel to be measured, and the second gas path shielding integrated structure is also used for electromagnetic shielding; An air path control module, the air path control module includes a valve and a program-controlled switch matched with the valve, the first air path shielding integrated structure and the second air path shielding integrated structure and the plurality of second air path shielding integrated structures are connected by the valve, and the opening and closing of the valve is controlled by the program-controlled switch; A temperature control module, which is arranged on the silicon resonance unit and the silicon piezoresistive unit; An external gas source, the external gas source is used to communicate with the first channel to be measured and the second channel to be measured when performing self-calibration of calibration parameters; An information processing circuit, the information processing circuit includes a preprocessing unit, an information acquisition unit and a self-calibration unit, the preprocessing unit is respectively connected to the resonance control module and the piezoresistive conditioning module, and is used to preprocess the measurement signals output by the resonance control module and the piezoresistive conditioning module, and the information acquisition unit is connected to the preprocessing unit, and is used to acquire the preprocessed measurement signals; The self-calibration unit is respectively connected to the program-controlled switch, the information acquisition unit, the temperature control module and the external gas source. The self-calibration unit is used to control all valves to open through the program-controlled switch when no regular maintenance instruction is received and the preset time is not reached, obtain the measurement signals of the silicon resonant meter core and the silicon piezoresistive meter core through the information acquisition unit, and perform power-on zero position self-calibration on the measurement signal of the silicon piezoresistive meter core based on the measurement signal of the silicon resonant meter core, and control all valves to close through the program-controlled switch after the power-on zero position self-calibration. The self-calibration unit is also used to adjust the temperature to multiple preset temperature points through the temperature control module when a regular maintenance instruction is received or the preset time is reached, and at each preset temperature point, adjust the pressure to multiple preset pressure points through the external gas source based on the measurement signal of the silicon resonant meter core as a reference, and obtain the measurement signal of the silicon piezoresistive meter core through the information acquisition unit to perform self-calibration of calibration parameters.

[0021] By applying this configuration, a multi-source heterogeneous pressure sensing system is provided. The system is based on the existing silicon resonant core and silicon piezoresistive core, and innovatively integrates the two cores to form a multi-channel multi-source heterogeneous pressure sensing system. The core-level integration is combined with the multi-core information integration processing. Compared with the multi-sensor level integration, it reduces the space occupied by the sensor housing, sensor circuit, internal gap of the sensor and gap between large-size sensors. Multiple cores can be integrated in the circuit in a matrix manner, which greatly reduces the system volume. By utilizing the high precision and high stability of the silicon resonant core and taking the silicon resonant core as the pressure reference, the system can realize regular online calibration and maintenance of the silicon piezoresistive core without disassembly and assembly by cooperating with an external gas source, a temperature control module and combining algorithms such as data correction and compensation, simplifying the calibration process and equipment configuration, and effectively improving work efficiency. Compared with using silicon resonant cores for all channels, the volume, weight and cost can be effectively reduced, and compared with using silicon piezoresistive cores for all channels, the measurement accuracy and stability can be effectively improved. The multi-source heterogeneous pressure sensing system significantly improves the performance of the silicon piezoresistive core measurement channel while using only one high-precision, high-stability silicon resonant core, and realizes high-precision, high-reliability, miniaturized, and low-cost measurement of multi-channel pressure. It is simple and practical, easy to implement and effective, and has strong feasibility. It can meet the coupling requirements of new weapons and equipment for atmospheric sensing systems in terms of high performance, low cost, and miniaturization, and can effectively improve the performance stability of the system in long-term applications, and realize convenient online calibration and maintenance of the system, which can expand the application field of the system. Compared with the prior art, the technical solution of the present invention can solve the technical problem that the multi-source heterogeneous system in the prior art cannot be calibrated and maintained online.

[0022] Among them, the present invention is based on the design concept of "three transformations", and the silicon resonant core is set on the resonant control module circuit board to realize the integrated design of the support structure of the silicon resonant core and the resonant control module. The metal cover is used as both an electromagnetic shielding structure and a part of the silicon resonant core gas path to realize the integrated design of the silicon resonant core gas path and the shielding structure, forming a miniaturized packaged silicon resonant core packaging unit. Two or more silicon piezoresistive cores are packaged together with the conditioning module through micro-assembly process and low-stress packaging process, and the metal cover is used to realize the integrated design of the gas path and metal shielding structure of multiple silicon piezoresistive cores to form a miniaturized silicon piezoresistive core packaging unit. The silicon resonant core packaging unit and the silicon piezoresistive core packaging unit are installed on the information processing circuit board in the system to ensure that the electromagnetic shielding shell (metal cover) and the signal stratum of the information processing circuit board are electrically conductive, and each sensor unit is electrically conductive with the information processing circuit board through pin welding.

[0023] In order to improve the measurement accuracy, in the embodiment of the present invention, two or more silicon piezoresistive cores of different ranges are miniaturized and integrated, and the gas path is connected by sharing a metal cover to form a single silicon piezoresistive unit, which jointly realizes the pressure measurement of one channel, with small size and low cost, wherein the ranges of multiple silicon piezoresistive cores in the same silicon piezoresistive unit are different. The low-pressure section mainly uses the measurement results of the small-range silicon piezoresistive core, and the high-pressure section mainly uses the measurement results of the large-range silicon piezoresistive core. Such a combined measurement can improve the accuracy of pressure measurement within the entire range (the measurement accuracy of the pressure sensor is generally a percentage of the full range, and using one sensor to measure the entire range will cause the absolute value of the measurement error in the low-pressure section to be larger). At the same time, two or more silicon piezoresistive cores constitute redundancy in hardware, and combined with fault management software, the reliability of pressure measurement can be improved, and the normal operation of the system can be ensured when individual cores fail.

[0024] Furthermore, in an embodiment of the present invention, the information processing circuit also includes a fault management unit, which is connected to the information acquisition unit and is used to determine whether each silicon piezoresistive core in the same silicon piezoresistive unit fails based on the signal collected by the information acquisition unit, and to eliminate the measurement signal of the failed silicon piezoresistive core. In addition, the information processing circuit also includes a power supply unit, which is used to convert the external power supply to the circuit board and supply power to each part through the circuit board. Through multi-core fault management and online rapid self-calibration, the reliability and maintainability of the system can be improved preferentially.

[0025] That is to say, in the embodiment of the present invention, in addition to carrying each sensor unit, the information processing circuit integrates the functions of silicon resonant sensor information collection, silicon piezoresistive sensor information collection, power supply conversion, information preprocessing, pressure solution, fault management, self-calibration, etc. Then, the information processing circuit board with multiple sensor units installed is reliably installed on the miniaturized controllable gas path module (gas path control module) to realize the connection and control of the gas path between the sensor units and the sealed connection of the electrical signals. Finally, the cover plate structure is installed to perform structural sealing to realize the integrated packaging of the multi-channel sensor system.

[0026] Furthermore, in the embodiment of the present invention, the temperature control module includes a heating device, a cooling device, a temperature measuring device, a constant temperature structure, etc., which are controlled by the self-calibration unit in the information processing circuit. According to the system application requirements, the pressure channel that requires temperature self-calibration is integrated and assembled and the temperature is controlled. The external gas source can be realized by a vacuum pump, a gas cylinder and a pressure reducing valve. The implementation method is well known to those skilled in the art and will not be repeated here.

[0027] like Figure 1 According to another aspect of the present invention, a self-calibration method for the multi-source heterogeneous pressure sensing system provided by the present invention is provided, and the method comprises: S1, connecting an external gas source to the first channel to be tested and the second channel to be tested; S2, the system is powered on and completes initialization and self-test; S3, determining whether a regular maintenance instruction has been received or a preset time has been reached, if not, proceeding to S4, if yes, proceeding to S5; S4, control all valves to open through program-controlled switches, obtain measurement signals of the silicon resonant meter core and the silicon piezoresistive meter core through the information acquisition unit, perform power-on zero position self-calibration on the measurement signal of the silicon resonant meter core based on the measurement signal of the silicon piezoresistive meter core, and control all valves to close through program-controlled switches after power-on zero position self-calibration; S5, adjust the temperature to multiple preset temperature points through the temperature control module, at each preset temperature point, adjust the pressure to multiple preset pressure points through an external gas source based on the measurement signal of the silicon resonant meter core, and obtain the measurement signal of the silicon piezoresistive meter core through the information acquisition unit to perform self-calibration of calibration parameters.

[0028] In this way, by utilizing the high precision and high stability of the silicon resonant meter movement and taking the silicon resonant meter movement as the pressure reference, and by coordinating with an external gas source, a temperature control module, and combining data correction and compensation algorithms, it is possible to achieve regular online calibration and maintenance of the silicon piezoresistive meter movement without disassembly, simplifying the calibration process and equipment configuration, and effectively improving work efficiency; it is possible to achieve online maintenance without disassembly of the system, and meet the performance indicators and application requirements of the system throughout its life cycle.

[0029] Among them, in the embodiment of the present invention, the power-on zero position self-calibration is performed in a static state, that is, the system is under static air conditions, so that the multiple pressure channels are under the same or similar pressure conditions. If the corresponding conditions are not met, when the power-on zero position self-calibration is performed, the pressure difference between the first channel to be measured and the second channel to be measured can be adjusted by the plug and / or the pressure regulating air source, so that the pressure difference is not greater than half of the accuracy requirement of the multi-source heterogeneous pressure sensing system. In addition, when the calibration parameter self-calibration is performed, the pressure is adjusted to multiple preset pressure points through an external air source based on the measurement signal of the silicon resonant meter core. The specific operation method is that the external air source provides positive and negative pressures that meet the calibration pressure range, and uses the high-precision device (silicon resonant meter core) as the control reference to display its specific output pressure value. In addition, the preset time in S3, that is, the maintenance cycle, can be set according to the system application requirements or the specific performance indicators of the device. The preset temperature point in S5 is the temperature calibration point, and the preset pressure point is the pressure calibration point. The temperature calibration point and the pressure calibration point are set according to actual application requirements. In order to improve the calibration accuracy, in the embodiment of the present invention, the temperature calibration point and the pressure calibration point involve the temperature and pressure ranges of the main applications of the system, especially the temperature and pressure ranges to which the performance of lower-precision devices (silicon piezoresistive core) is sensitive.

[0030] Furthermore, in the above embodiment, the power-on zero position self-calibration of the measurement signal of the silicon piezoresistive meter core is performed based on the measurement signal of the silicon resonant meter core, including: Obtaining measurement signals of the silicon resonant meter core and each silicon piezoresistive meter core within a preset time period; Calculate the measurement difference between the measurement signal of each silicon piezoresistive meter core and the measurement signal of the silicon resonant meter core at the corresponding measurement time; Calculate the average value of the measured difference for each silicon piezoresistive meter core; The average value of the measured difference corresponding to each silicon piezoresistive core is used for power-on zero position self-calibration.

[0031] That is, in subsequent use, the actual measurement result of the silicon piezoresistive meter core minus the average value of the corresponding measurement difference is used as the measurement result after power-on zero position self-calibration.

[0032] In addition, in the above embodiment, obtaining the measurement signal of the silicon piezoresistive core through the information acquisition unit to perform self-calibration of the calibration parameters includes: for each silicon piezoresistive core, fitting its measurement signal to obtain the calibration parameters, and updating the calibration parameters. As a specific embodiment of the present invention, a 5th-order pressure-6th-order temperature fitting model is used when fitting the measurement signal of each silicon piezoresistive core. The number of temperature calibration points and pressure calibration points is greater than the order in the calibration fitting calculation. The fitting parameters of the fitting model are the calibration parameters. The calibrated calibration parameters are automatically written into the software, thereby completing the regular self-calibration maintenance of the system.

[0033] In order to facilitate a clearer understanding of the self-calibration method provided by the present invention, the above-mentioned processes will be described in detail below by taking practical application as an example. Relevant technical personnel in the field should know that this example is only for a clearer understanding of the self-calibration method provided by the present invention, and does not impose any technical limitation on it.

[0034] In this embodiment, the multi-source heterogeneous pressure sensing system is a hybrid integration of a 1-channel silicon resonant chip and a 4-channel silicon piezoresistive chip. At the same time, the system is equipped with a temperature control module for each of the five pressure sensing units, that is, each pressure sensing unit integrates a heating plate, a cooling plate, a constant temperature structure, a temperature sensor device, etc., and the temperature environment of each pressure sensing unit is controlled by the system circuit. The five pressure channels are concentrated on one side of the system structure, and the pressure difference can be ignored in the static state.

[0035] In terms of performance indicators, the system pressure range is 1kPa~110kPa, the operating temperature range is -45℃~85℃, and the accuracy requirement for each pressure channel is better than 0.04%FS (i.e. 44Pa). For the silicon resonant chip, the nominal accuracy is 0.02%FS (i.e. 22Pa), and the nominal accuracy of the silicon piezoresistive chip is 0.1%FS (i.e. 110Pa). In addition, according to test data, the time drift error of the silicon piezoresistive chip used in this system reaches 0.04%FS after 3 years, so the maintenance period of the system is set to 3 years.

[0036] When the system is powered on, all five channels are in still air. At this time, the pressure data of the silicon resonant chip is used as the benchmark for this power-on. After the system completes initialization, self-test and other processes and enters the formal measurement process, the software automatically records the difference between the measurement data of the 4-channel silicon piezoresistive chip and the silicon resonant chip within 1 second, takes the average value and records it (set as Δ 差值 ), and then the corresponding Δ is subtracted from the measured value of each channel silicon piezoresistive chip during the measurement process. 差值 , that is, the system's power-on zero position self-calibration process is completed. Through this process, the performance of the silicon piezoresistive chip of each channel can be improved from the initial 0.1%FS to 0.02%FS level. Combined with the partial error margin caused by the drift of silicon piezoresistive devices in the subsequent use process, the system accuracy can be better than 0.04%FS performance indicators.

[0037] When the 3-year maintenance cycle is reached, the multi-source heterogeneous pressure sensing system is equipped with simple external gas source equipment such as vacuum pumps, gas cylinders and pressure reducing valves, which are connected to the gas path of the system. The upper system sends maintenance instructions, and the multi-source heterogeneous system starts the calibration parameter self-calibration work. The system software (self-calibration unit) controls the temperature control module to perform constant temperature control on each silicon resonant chip and silicon piezoresistive chip. The calibration temperature points are set to -45℃, -25℃, 0℃, 25℃, 45℃, 65℃, and 85℃, covering the full temperature operating range of the system. When the system reaches each temperature point, the input of the system pressure is controlled by adjusting the external gas source equipment, and the calibration pressure points such as 1kPa, 10kPa, 30kPa, 50kPa, 70kpa, 90kPa, and 110kPa that meet the pressure range are set based on the output of the silicon resonant chip. The system software automatically records the original measurement data of the silicon resonant chip and the 4-channel silicon piezoresistive chip.

[0038] This system uses 5th-order pressure-6th-order temperature fitting. The initial model fitting parameters are calculated by the least squares method through the calibration process at the factory. After regular maintenance, the recorded self-calibration data is re-fitted and calculated by the software running the least squares method and other algorithms to obtain the self-calibrated model fitting parameters, and write them into the system software to replace the initial model fitting parameters, thus completing the system's regular calibration parameter self-calibration process. Through this process, the error caused by time drift of the silicon piezoresistive chip can be effectively eliminated, thereby achieving long-term maintenance of the system's accuracy level.

[0039] Through the above system's power-on zero position self-calibration and regular online calibration parameter self-calibration method, the system can achieve an accuracy better than 0.04%FS within the specified range, meet the system's performance indicators and application requirements throughout its life cycle, and achieve online maintenance without disassembly of the system.

[0040] According to another aspect of the present invention, an aircraft is provided, and the aircraft includes the multi-source heterogeneous pressure sensing system proposed in the present invention. Since the multi-source heterogeneous pressure sensing system proposed in the present invention can significantly improve the performance of the silicon piezoresistive core measurement channel when only one high-precision, high-stability silicon resonant core is used, and realize high-precision, high-reliability, miniaturized, and low-cost measurement of multi-channel pressure, it can meet the coupling requirements of new weapons and equipment for atmospheric sensing systems in terms of high performance, low cost, and miniaturization, and can effectively improve the performance stability of the system in long-term applications, and realize convenient online calibration and maintenance of the system, therefore, applying it to an aircraft can significantly improve the performance of the aircraft.

[0041] In summary, the present invention provides a multi-source heterogeneous pressure sensing system, a self-calibration method and an aircraft. The system is based on the existing silicon resonant watch core and the silicon piezoresistive watch core, and innovatively integrates the two watch cores to form a multi-channel multi-source heterogeneous pressure sensing system. The integration of the watch core level is combined with the information integration processing of multiple watch cores. Compared with the multi-sensor level integration, the space occupied by the sensor housing, the sensor circuit, the internal gap of the sensor and the gap between large-size sensors is reduced. Multiple watch cores can be integrated in the circuit in a matrix manner, which greatly reduces the system volume. By utilizing the high precision and high stability of the silicon resonant watch core, the silicon resonant watch core is used as the pressure reference. By cooperating with an external gas source, a temperature control module and combining algorithms such as data correction and compensation, regular online calibration and maintenance of the silicon piezoresistive watch core without disassembly and assembly can be achieved, the calibration process and equipment configuration are simplified, and the work efficiency is effectively improved. Compared with the use of silicon resonant watch cores in all channels, the volume, weight and cost can be effectively reduced. Compared with the use of silicon piezoresistive watch cores in all channels, the measurement accuracy and stability can be effectively improved. The multi-source heterogeneous pressure sensing system significantly improves the performance of the silicon piezoresistive core measurement channel while using only one high-precision, high-stability silicon resonant core, and realizes high-precision, high-reliability, miniaturized, and low-cost measurement of multi-channel pressure. It is simple and practical, easy to implement and effective, and has strong feasibility. It can meet the coupling requirements of new weapons and equipment for atmospheric sensing systems in terms of high performance, low cost, and miniaturization, and can effectively improve the performance stability of the system in long-term applications, and realize convenient online calibration and maintenance of the system, which can expand the application field of the system. Compared with the prior art, the technical solution of the present invention can solve the technical problem that the multi-source heterogeneous system in the prior art cannot be calibrated and maintained online.

[0042] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0043] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-source heterogeneous pressure sensing system, characterized in that: The system comprises: A silicon resonance unit, the silicon resonance unit comprising a silicon resonance core, a support structure, a resonance control module and a first air path shielding integrated structure, the support structure and the resonance control module are designed as an integrated whole, the silicon resonance core is arranged on the support structure and connected to the resonance control module, the first air path shielding integrated structure is a metal cover, the first air path shielding integrated structure sealing cover is arranged on the silicon resonance core, the support structure and the resonance control module, the first air path shielding integrated structure has a first air nozzle for communicating with a first channel to be measured, and the first air path shielding integrated structure is also used for electromagnetic shielding; One or more silicon piezoresistive units, each of which includes more than two silicon piezoresistive cores, a piezoresistive conditioning module and a second air path shielding integrated structure, the silicon piezoresistive core is connected to the piezoresistive conditioning module, the second air path shielding integrated structure is a metal cover, a sealing cover of the second air path shielding integrated structure is provided on the silicon piezoresistive core and the piezoresistive conditioning module, the second air path shielding integrated structure has a second air nozzle for communicating with a second channel to be measured, and the second air path shielding integrated structure is also used for electromagnetic shielding; An air path control module, the air path control module comprising a valve and a program-controlled switch coordinated with the valve, the first air path shielding integrated structure and the second air path shielding integrated structure as well as multiple second air path shielding integrated structures are connected via the valve, and the opening and closing of the valve is controlled by the program-controlled switch; A temperature control module, wherein the temperature control module is arranged on the silicon resonance unit and the silicon piezoresistive unit; An external gas source, the external gas source being used to communicate with the first channel to be measured and the second channel to be measured when performing self-calibration of calibration parameters; An information processing circuit, the information processing circuit comprising a preprocessing unit, an information acquisition unit and a self-calibration unit, the preprocessing unit being connected to the resonance regulation module and the piezoresistive conditioning module respectively, and being used for preprocessing the measurement signals output by the resonance regulation module and the piezoresistive conditioning module, and the information acquisition unit being connected to the preprocessing unit, and being used for acquiring the preprocessed measurement signals; The self-calibration unit is connected to the program-controlled switch, the information acquisition unit, the temperature control module and the external air source respectively. The self-calibration unit is used to control all the valves to open through the program-controlled switch when no regular maintenance instruction is received and the preset time is not reached, obtain the measurement signals of the silicon resonant meter core and the silicon piezoresistive meter core through the information acquisition unit, and perform power-on zero position self-calibration on the measurement signal of the silicon resonant meter core based on the measurement signal of the silicon resonant meter core, and control all the valves to close through the program-controlled switch after power-on zero position self-calibration. The self-calibration unit is also used to adjust the temperature to multiple preset temperature points through the temperature control module when a regular maintenance instruction is received or a preset time is reached, and at each preset temperature point, adjust the pressure to multiple preset pressure points through the external air source based on the measurement signal of the silicon resonant meter core as a reference, and obtain the measurement signal of the silicon piezoresistive meter core through the information acquisition unit to perform self-calibration of calibration parameters.

2. The system according to claim 1, characterized in that The measuring ranges of multiple silicon piezoresistive cores in the same silicon piezoresistive unit are different.

3. A self-calibration method for the multi-source heterogeneous pressure sensing system according to claim 1 or 2, characterized in that: The method comprises: S1, connecting an external gas source to the first channel to be tested and the second channel to be tested; S2, the system is powered on and completes initialization and self-test; S3, determining whether a regular maintenance instruction has been received or a preset time has been reached, if not, proceeding to S4, if yes, proceeding to S5; S4, controlling all valves to open through a program-controlled switch, obtaining measurement signals of a silicon resonant meter core and a silicon piezoresistive meter core through an information acquisition unit, performing power-on zero position self-calibration on the measurement signal of the silicon resonant meter core based on the measurement signal of the silicon piezoresistive meter core, and controlling all valves to close through the program-controlled switch after power-on zero position self-calibration; S5, adjusting the temperature to a plurality of preset temperature points through the temperature control module, at each of the preset temperature points, adjusting the pressure to a plurality of preset pressure points through the external gas source based on the measurement signal of the silicon resonant meter core, and acquiring the measurement signal of the silicon piezoresistive meter core through the information acquisition unit to perform self-calibration of calibration parameters.

4. The method according to claim 3, characterized in that When performing power-on zero position self-calibration, the pressure difference between the first channel to be measured and the second channel to be measured is adjusted by a plug and / or a pressure regulating gas source so that the pressure difference is no greater than half of the accuracy requirement of the multi-source heterogeneous pressure sensing system.

5. The method according to claim 4, characterized in that Taking the measurement signal of the silicon resonant meter core as a reference, performing power-on zero position self-calibration on the measurement signal of the silicon piezoresistive meter core includes: Acquiring measurement signals of the silicon resonant meter core and each of the silicon piezoresistive meter cores within a preset time period; Calculating the measurement difference between the measurement signal of each silicon piezoresistive meter core and the measurement signal of the silicon resonant meter core at the corresponding measurement time respectively; Calculating the average value of the measurement difference for each of the silicon piezoresistive cores; The power-on zero position self-calibration is performed using the average value of the measurement difference corresponding to each silicon piezoresistive meter core.

6. The method according to claim 5, characterized in that Acquiring the measurement signal of the silicon piezoresistive core through the information acquisition unit to perform self-calibration of calibration parameters includes: fitting the measurement signal of each silicon piezoresistive core to obtain calibration parameters, and updating the calibration parameters.

7. The method according to claim 6, characterized in that The 5th-order pressure-6th-order temperature fitting model is used to fit the measurement signal of each silicon piezoresistive core.

8. An aircraft, characterized in that: The aircraft includes the multi-source heterogeneous pressure sensing system according to claim 1 or 2.

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