CN115493801A - Steady-state pressure and dynamic data phase synchronization parallel acquisition and preprocessing system - Google Patents

Abstract

The invention discloses a synchronous parallel acquisition and preprocessing system for steady-state pressure and dynamic data phase, which relates to the field of data processing of wind tunnel experiments and comprises the following components: at least one group of steady-state pressure acquisition units for large-scale measurement of the steady load of the aircraft model; at least one group of dynamic data acquisition units for measuring the unsteady loads of the aircraft model; the control unit is used for realizing the synchronization of the measurement data acquisition of the steady-state pressure acquisition unit and the dynamic data acquisition unit; and a terminal connected with the steady-state pressure acquisition unit and the dynamic data acquisition unit through a network switch is loaded with synchronous acquisition and preprocessing software. The invention provides a steady-state pressure and dynamic data phase synchronization parallel acquisition and preprocessing system, which can realize synchronous integrated measurement of steady and unsteady loads on the surface of an aircraft model and obtain load information data of the same phase or moment so as to meet the requirements of synchronous parallel measurement tests of the steady and unsteady loads of the aircraft.

Description

Steady-state pressure and dynamic data phase synchronization parallel acquisition and preprocessing system

Technical Field

The invention relates to the field of data processing of wind tunnel experiments. More specifically, the invention relates to a synchronous parallel acquisition and preprocessing of steady-state pressure and dynamic data phase used in wind tunnel experimental data acquisition, analysis and processing.

Background

The realization of the synchronous testing and the coupling analysis of multiple physical fields is a significant problem for the resistance reduction, the noise reduction and the structural safety assessment of the aerospace craft. The method comprehensively evaluates the pneumatic, vibration and acoustic characteristics of the tested model through synchronous parallel measurement and coupling analysis of a plurality of physical fields of flow field, noise, vibration and pulsating pressure, and plays a very important role in improving the test and analysis level of the drag reduction and noise reduction design and the structure safety evaluation of the aircraft.

In the current wind tunnel test, a polling acquisition mode is adopted for large-scale steady-state pressure measurement, which cannot be performed in parallel and synchronously, wherein large scale refers to that pressure acquisition can be performed on hundreds of point locations through one group of steady-state pressure acquisition units, and pressure acquisition can be performed on hundreds of point locations through cooperation of a plurality of groups of steady-state pressure acquisition units; although the dynamic data acquisition system uses the same-frequency clock in each acquisition channel, the dynamic data acquisition system cannot be strictly synchronized due to no phase locking, and especially under the condition of a large data volume and multi-channel acquisition board card, the time offset is larger. In addition, test systems used for large-scale steady-state pressure acquisition and dynamic data acquisition are mutually independent and different, and asynchronous flow field, noise, vibration and pulsating pressure multi-physical-field load data cannot be extracted and identified in the aspects of multi-physical-field coupling characteristic extraction, parameter fusion analysis and the like.

Disclosure of Invention

An object of the present invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.

To achieve these objects and other advantages in accordance with the purpose of the invention, there is provided a steady-state pressure and dynamic data phase synchronization parallel acquisition and preprocessing system, comprising:

at least one group of steady state pressure acquisition units for measuring the steady load of the aircraft model;

at least one group of dynamic data acquisition units for measuring the unsteady loads of the aircraft model;

the control unit is used for realizing the synchronization of the measurement data acquisition of the steady-state pressure acquisition unit and the dynamic data acquisition unit;

a terminal connected with the steady-state pressure acquisition unit and the dynamic data acquisition unit through a network switch and loaded with synchronous acquisition and preprocessing software;

wherein the phase synchronization is configured to include:

the method comprises the steps that in the same large class of acquisition units, the start and stop points of recorded data in all acquisition cards are determined through the case cascade connection and external common-frequency clock synchronous trigger control, and the synchronous acquisition among the acquisition units in the same large class is realized;

in any group of acquisition units, each measurement channel adopts an independent analog-digital converter (ADC), and synchronous acquisition of each channel is realized in one group of acquisition units through a back bus;

the method comprises the steps that starting and stopping points of recorded data in all acquisition cards are determined among different types of acquisition units through an external common-frequency clock and synchronous triggering, and synchronous timestamps are inserted into each group of data through a synchronous counter, so that synchronous acquisition of different types of data is realized.

Preferably, each steady-state pressure acquisition unit is configured to include:

the pressure sensors are matched with the points to be measured on the gas path connecting assembly;

the first signal conditioning circuit is in communication connection with each pressure sensor to construct a corresponding measuring channel;

the pressure scanning valve assembly is in communication connection with each first signal conditioning circuit so as to realize synchronous acquisition of each pressure sensor;

the first chassis is used for integrating all the pressure scanning valve components, and a first controller with an operating system is arranged in the first chassis;

a pressure controller connected to each pressure scanning valve assembly to provide a standard pressure.

Preferably, the dynamic data acquisition unit is configured to include:

the sensor comprises a plurality of types of sensors for collecting noise, vibration, temperature, strain and pulsating pressure related physical quantities;

the second signal conditioning circuit is in communication connection with each sensor to construct a corresponding measuring channel;

the dynamic data acquisition assembly is in communication connection with each second signal conditioning circuit to realize synchronous acquisition of each sensor;

and a second case for integrating the dynamic data acquisition assembly, wherein a second controller with an operating system is arranged in the second case.

Preferably, each chassis is respectively provided with a controller slot into which a plurality of acquisition boards can be inserted, and a chassis back plate with a synchronous trigger clock bus;

each pressure scanning valve assembly, each dynamic data acquisition assembly is configured to include:

the first FPGA is used for processing and outputting the signal input by the signal conditioning circuit;

the first phase-locked loop PLL is in communication connection with the first FPGA, the first clock management module and the CPU;

the external communication interface, the synchronous clock signal and the synchronous trigger signal are in communication connection with the first clock management module and the CPU through the control bus.

Preferably, the control unit is configured to include:

the rack is provided with a front panel with a signal interface;

the second FPGA is arranged inside the rack;

the second phase-locked loop PLL is in communication connection with the second FPGA, the second clock management module and the synchronous signal generator;

the control unit is in communication connection with each pressure scanning valve assembly and each dynamic data acquisition assembly through a shunt.

Preferably, the system architecture of the software adopts a distributed network architecture, which is divided into 5 layers from bottom to top, and the following are performed in sequence: the device comprises a signal layer, an acquisition layer, a transmission layer, a monitoring layer and a data layer.

Preferably, the basic functions of the software include: user and authority management, parameter configuration, sensor field calibration, real-time acquisition and display of sensor signals, acquired data preprocessing, data playback and data export;

wherein the parameter configuration comprises:

the system parameter configuration comprises the configuration of sampling frequency, average point number, acquisition mode and whether system parameters are synchronized or not;

channel parameter configuration, including configuration of data type, data identification, measuring range, filter type and cut-off frequency parameter;

the output parameter configuration comprises the configuration of the output format, the output path and the network transmission path parameter, and the output configuration parameter can be independently stored and can also be loaded with configuration information;

and test parameter configuration, including configuration of test name, model code number, model state and test train number parameters.

The invention at least comprises the following beneficial effects: the steady-state pressure and dynamic data phase synchronization parallel acquisition and preprocessing system can complete synchronous integrated measurement of the steady and unsteady loads on the surface of the aircraft model, and obtain load information data of the same phase or moment so as to meet the test requirements of the synchronous measurement of the steady and unsteady loads of the aircraft.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

FIG. 1 is a schematic block diagram of a steady state pressure and dynamic data phase synchronized parallel acquisition and preprocessing system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the basic functional structure of the data acquisition and preprocessing software of the present invention;

FIG. 3 is a schematic diagram of the distribution architecture of the data acquisition and preprocessing software of the present invention;

FIG. 4 is a functional block diagram of the steady state pressure measurement assembly of the present invention;

FIG. 5 is a functional block diagram of the dynamic pressure measurement assembly of the present invention;

FIG. 6 is a functional block diagram of the control unit of the present invention;

the system comprises a steady-state pressure acquisition unit-1, a dynamic data acquisition unit-2, a control unit-3, a network switch-4, a terminal-5, a pressure controller-6, a pressure sensor-110, a first signal conditioning circuit-120, a pressure scanning valve assembly-130, a multi-type sensor-210, a second signal conditioning circuit-220, a dynamic data acquisition assembly-230, a first FPGA I-131, a first FPGA II-231, a first phase-locked loop PLL I-132, a first phase-locked loop PLL II-232, a first clock management module I-133, a first clock management module II-233, a CPU I-134, a CPU II-234, a communication interface I-135, a communication interface II-235, a synchronous clock signal I-136, a synchronous clock signal II-236, a synchronous trigger signal I-137, a synchronous trigger signal II-237, a control bus I-138, a control bus II-238, a second FPGA-30, a second phase-locked loop PLL-31, a second clock management module-32 and a synchronous signal generator-33.

Detailed Description

The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

It is to be understood that in the description of the present invention, the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are used only for convenience in describing the present invention and for simplification of the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise specifically stated or limited, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like are used in a broad sense, and for example, "connected" may be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, and a communication between two elements.

Fig. 1 shows an implementation form of a steady-state pressure and dynamic data phase synchronization parallel acquisition and preprocessing system according to the present invention, which includes:

the system comprises at least one group of steady state pressure acquisition units 1 for carrying out large-scale measurement on the steady load of the aircraft model, wherein the steady state pressure acquisition units receive pressure signals, and the large scale refers to that pressure acquisition can be carried out on hundreds of point locations through one group of steady state pressure acquisition units or pressure acquisition can be carried out on hundreds of point locations through cooperation of a plurality of groups of steady state pressure acquisition units;

the dynamic data acquisition units 2 are used for measuring the unsteady load of the aircraft model, receive sensor signals and convert the signals into digital quantity after conditioning;

the control unit 3 is used for realizing the synchronization of the acquisition of the measured data of the steady-state pressure acquisition unit and the dynamic data acquisition unit, and in application, the control unit provides an external synchronization trigger signal so as to realize the signal synchronization of a steady-state pressure signal and a dynamic sensor signal through the control unit, and a detection signal is integrally sent to a main control computer (namely a terminal) through a network switch;

the terminal 5 is connected with the steady-state pressure acquisition unit and the dynamic data acquisition unit through the network switch 4, synchronous acquisition and preprocessing software is loaded on the terminal, the data acquisition and preprocessing software mainly aims at the aircraft test process, the measurement of relevant physical quantities is carried out at different positions of a model, the mechanical, thermal, acoustic and other physical information sensed on the surface or inside of the model is obtained, further the relevant physical quantities of the test are analyzed, and the coupling feature extraction, identification and parameter fusion analysis are completed according to the obtained time domain and frequency domain changes of the different physical quantities and the mutual internal relevance; according to the characteristic information of different physical quantities, different physical signal amplitudes and frequency distribution diagrams of different key positions of the aircraft can be drawn according to the key positions in the three-dimensional structure of the aircraft part, wherein the line unit displays a one-dimensional line graph, and the plane unit displays a two-dimensional cloud graph. The software can conveniently configure system parameters, set parameters such as measuring range, measuring type, filtering and sampling frequency of the system in a program-controlled manner, complete real-time acquisition and preprocessing of signals, and realize services such as field calibration, signal acquisition, data preprocessing, data playback and data export;

for steady state pressure and dynamic data, the system configuration parameters include, but are not limited to: sampling frequency, average point number, acquisition mode, synchronization and other system parameters, and independently storing and loading configuration information during application;

the software starts or stops collecting data according to an external trigger signal, and the triggering mode includes but is not limited to: network command triggering, TTL level triggering and manual click triggering;

for a steady-state pressure acquisition part, a zero calibration function and the like must be provided;

an acquisition mode: when the steady-state pressure and the dynamic data acquisition are independently used, three acquisition modes of continuous acquisition, step acquisition and manual acquisition are respectively provided; when used simultaneously, the default is a synchronous, continuous acquisition mode.

Channel parameter configurations include, but are not limited to: data type, data identification, range, filter type and its cut-off frequency. The configuration information can be saved and loaded separately.

Output parameter configurations include, but are not limited to: output format, output path, network transmission path; the configuration information can be saved and loaded separately.

Experimental parameter configurations include, but are not limited to: test name, model code, model state and test train number; the configuration information can be saved and loaded separately.

And (3) real-time display function: the method comprises the steps of test information display, data numerical value display and curve display.

The data can be preprocessed, and the preprocessing comprises functions of smoothing, filtering, data intercepting, compressing, deleting, storing, amplitude analyzing, frequency domain transforming, time frequency analyzing and the like. The method can automatically count various information such as the maximum value, the minimum value, the average value, the mean square value, the alternating current component, the direct current component, the fundamental frequency and the like of each channel.

The filtering modes comprise a Butterworth filter, a Chebyshev filter, an inverse Chebyshev filter, an Elliptic filter, a Bessel filter, a Median filter and the like.

For strain and temperature signal acquisition, the software should have the capability of setting parameters such as temperature compensation, bridge nonlinear compensation, correction coefficients, long wire attenuation compensation, and the like.

And data and curve reports such as WORD, EXCEL and the like can be generated by a user in a customized manner, so that the user can conveniently archive and print the test result.

The data playback function is provided, and specific parameters such as playback speed, playback data length, playback selection point number and the like during data playback can be set. When data is played back, the function of enlarging and reducing the curve is provided under the pause interface, and when the data is positioned on the curve, the XY coordinate values of the current point are displayed. When there are a plurality of curves, one curve may be arbitrarily selected. The data of two channels can be arbitrarily selected and freely combined into an X-Y curve graph. Real-time spectrum analysis can be carried out on the playback data, and a time domain curve and a spectrogram are synchronously displayed.

Further, the main technical indexes measured by the software system include: measurement object: steady state pressure, voltage signal; number of steady state pressure measurements: in 100PSI range, the measuring point is more than or equal to 32;15PSI measuring range, measuring point is more than or equal to 32; number of dynamic load acquisition channels: not less than 32; and (3) interface expansion: under the condition that other technical indexes are not reduced, the number of the measuring points/channels of the whole set of system has the capacity of expanding to be more than or equal to 256; phase synchronization of electric signals: the deviation between the dynamic load data channels, between the steady-state pressure data and the dynamic load data is less than or equal to 0.003ms; precision: pressure measurement accuracy is less than or equal to 0.05% FS; voltage measurement accuracy is less than or equal to 0.03% FS; steady state pressure measurement range: 100PSI,15PSI; differential pressure; voltage signal input range: -10V to +10V; dynamic range (dBFS): not less than 150dB; common mode rejection ratio: more than or equal to 140dB (gain is more than or equal to 100);

wherein the phase synchronization is configured to include:

the method comprises the steps that in the same large class of acquisition units, the start and stop points of recorded data in all acquisition cards are determined through the case cascade connection and external common-frequency clock synchronous trigger control, and the synchronous acquisition among the acquisition units in the same large class is realized;

in any group of acquisition units, each measurement channel adopts an independent analog-digital converter (ADC), and synchronous acquisition of each channel is realized in one group of acquisition units through a back bus;

the method comprises the steps that starting and stopping points of recorded data in all acquisition cards are determined among different types of acquisition units through an external common-frequency clock and synchronous triggering, and synchronous timestamps are inserted into each group of data through a synchronous counter, so that synchronous acquisition of different types of data is realized. The case cascade synchronization means that a plurality of case clocks are synchronized through a same-frequency clock, different frequency data are aligned by time marks, the synchronous triggering means that a trigger and the clock are external signals for establishing system time, the frequency of occurrence of events is set by clock signals, when the acquisition starts, the trigger acts, and the starting point of data recording in all the acquisition cards is determined through trigger signals.

The steady-state pressure acquisition unit and the dynamic data acquisition unit can independently measure a steady-state pressure signal and a dynamic signal, and can also synchronously measure (also can be called as acquisition) the steady-state pressure signal and the dynamic signal through the synchronously acquired control unit, the acquisition terminal of each measurement unit interacts information with the main control computer through a network, and the functions of remote acquisition control, remote data monitoring, data processing analysis and the like can be realized by combining the matched data acquisition and preprocessing software on the terminal.

In another example, as shown in fig. 4, each steady-state pressure acquisition unit is configured to include:

a plurality of pressure sensors 110 which are matched with the point to be detected on the air path connecting assembly;

a first signal conditioning circuit 120 communicatively coupled to each pressure sensor to construct a corresponding measurement channel;

the pressure scanning valve assembly 130 (also called as a steady-state data acquisition assembly) is in communication connection with each first signal conditioning circuit so as to realize synchronous acquisition of each pressure sensor, and a modular design is adopted, so that the interface is expandable and the overall technical index of the system is not influenced;

the first case (not shown) is used for integrating all pressure scanning valve assemblies, a first controller (also called a pressure measurement case) with an operating system is arranged in the first case, all the pressure scanning valve assemblies are inserted into the pressure measurement case to complete modular integration of pressure measurement, the first case is a 4U standard frame case and is provided with a core controller slot, a maximum of 8 acquisition board cards can be inserted, the first case is inserted in a quick-insert structure, a panel is provided with locking screws, the board cards can be reinforced to be installed after being screwed down, the core controller is a core component of a steady-state pressure measurement system, is equivalent to a CPU and a mainboard of acquisition equipment, and can complete functions of data acquisition management, acquisition instruction sending, data transmission and the like. The operating system of the core controller is an RT real-time operating system. When the real-time operating system interacts with external data, the real-time operating system can process the data at a high enough speed, the processing result can control the production process or make a quick response to the processing system within a specified time, all available resources are scheduled to complete real-time tasks, and all real-time tasks are controlled to run in a coordinated and consistent mode. Compared with a time-sharing operating system, the system has the advantages of timely response and high reliability. For the data acquisition processing server, the synchronous acquisition component is like a black box, a preset program in the core controller automatically calls and operates a synchronous acquisition function, an acquisition instruction sent by the server is received by adopting a driving program, and acquired data are sent to the data acquisition processing server;

a pressure controller 6 connected to each pressure scanning valve assembly to provide a standard pressure.

The portable pressure controller mainly outputs a standard pressure to provide a standard pressure source so as to conveniently finish the work of checking and troubleshooting the pressure scanning valve module. In the scheme, parameter indexes of each pressure scanning valve component need to meet the requirements of the table 1 so as to have the capacity of phase synchronization acquisition between measuring points and between each pressure scanning valve component and dynamic data acquisition;

TABLE 1

In practical applications, the main technical index measurements of a module-level pressure-sweep valve assembly satisfy: a channel: 8 channels; measurement mode: differential pressure; acquisition precision: 0.03% by weight of FS; working temperature: -20 ℃ to 80 ℃; the synchronization mechanism comprises: each measuring point is independently and synchronously sampled in parallel, and the synchronous deviation is less than or equal to 0.003ms; sampling frequency: the maximum sampling frequency of each measuring point is more than or equal to 100KHz; the power supply mode comprises the following steps: DC24V; the triggering mode is as follows: external triggering and instruction triggering; zero self-calibration: comprises the following steps; temperature correction: the temperature compensation function is provided. And the number of pressure scanning valve assemblies in one steady-state pressure acquisition unit comprises: 4 blocks of range 100PSI, 32 channels in total; 4 blocks of range 15PSI, 32 channels in total; and (3) synchronization: the synchronous deviation of the electric signals between the measuring points in the unit and the dynamic data acquisition unit is less than or equal to 0.003ms;

as shown in fig. 5, the dynamic data acquisition unit is configured to include:

the sensors 210 are used for collecting physical quantities related to noise, vibration, temperature, strain and pulsating pressure;

and a second signal conditioning circuit 220 which is in communication connection with each sensor to construct a corresponding measuring channel, wherein the second signal conditioning circuit adopts a register type (SAR) analog-digital converter (ADC), and the acquisition precision is as follows: 24 bits; synchronous sampling: 4, a channel; input impedance: 10G omega; maximum throughput of the channel: 1MSPS; temperature range: -40 ℃ to +125 ℃. The Common Mode Rejection Ratio (CMRR), which represents the ability of a differential amplifier circuit to reject common mode signals and amplify differential mode signals, is often expressed in logarithmic form and is calculated as: CMR (dB) =20log | AudAuc |, where Aud is the differential mode voltage amplification and Auc is the common mode amplification. The tested common mode rejection ratio is larger than 130db;

the dynamic data acquisition assembly 230 is in communication connection with each second signal conditioning circuit to realize synchronous acquisition of each sensor, the dynamic data acquisition unit can realize acquisition and conditioning of external sensor signals, and comprises 8 4-channel dynamic data acquisition assemblies, and the synchronous deviation of electric signals between measurement points in the unit and a steady-state pressure data acquisition system is less than or equal to 0.003ms;

carry out integrated second quick-witted case (not shown) to dynamic data acquisition subassembly, be provided with the second controller (not shown) of taking operating system in it, the second controller is the core component of dynamic data acquisition unit, be equivalent to collection equipment's CPU and mainboard, can accomplish functions such as data acquisition management, collection instruction send, data transmission, functionally the same with the first controller of steady state pressure acquisition unit, in actual application, the design key point of second machine case and first machine case have unanimity, technical indicator mainly includes: 1 core controller slot; providing 8 slots; 2 front panel LEDs for monitoring power supply and working state of the case; the chassis backboard bus is provided with a synchronous trigger clock, so that external trigger synchronization with other equipment can be realized; an extended working temperature of 0-55 ℃; the rack type structure can be arranged on a standard 19U, and further each case adopts an European card (Eurocard) structure, and the European card adopts a vertical installation and front extraction structure, so that the heat dissipation, the shock resistance and the easy maintenance of the system are improved.

In the scheme, each dynamic data acquisition assembly of the dynamic data acquisition unit is based on modular design, multiple devices can work synchronously in parallel, each channel can be respectively connected with different types of sensors to perform high-precision phase synchronous acquisition on physical quantities such as noise, vibration, temperature, strain, pulsating pressure and the like, each measurement channel is provided with an independent high-stability signal conditioning circuit, and each performance index of the signal conditioning circuit meets the requirements of a table 2 so as to have the capacity of phase synchronous acquisition between measurement points and between each dynamic data acquisition assembly and steady-state pressure measurement.

TABLE 2

The dynamic data acquisition unit belongs to a high-precision and high-stability system, and the parameter indexes such as common mode rejection ratio, long-term drift, gain drift, linearity and the like are specific basis for ensuring the high precision and high stability of the system. The factors influencing the parameter indexes are integrally considered in aspects including circuit design, temperature distribution control, anti-interference design and the like. Therefore, in the practical application of the method,

for the design of a signal conditioning circuit, a dynamic data signal conditioning component adopts a rapid and extremely low noise conditioning module, has a stable and low background noise conditioning technology, can reliably and repeatedly represent the characteristics of low-resistance materials and devices, can provide more stable and reliable and lower noise performance, reduces the noise to 1nV through averaging multiple readings, and can provide 110dB serial-mode suppression (NMRR) through a power supply synchronization technology, thereby minimizing the influence of AC common-mode current.

The low noise input amplifier and the high tuning input protection circuit make the conditioning noise as low as 8nVp-p, and further improve the noise performance through the integral time of the whole period. Algorithms such as mathematical data average, standard deviation, calibration measurement and the like are built in, the signal conditioning capability is greatly improved, a low-noise input circuit and a high-stability current source are combined through an algorithm processing circuit, the influence of stray thermal electromotive force (EMF) can be eliminated through bias compensation, and the stray EMF can cause measurement errors. The low power ohmic and low voltage resistance measurement capability allows repeated measurements to be taken where low voltage (20 mV) is required to avoid oxidation breakdown.

For the thermal balance control, the dynamic data acquisition terminal adopts a low-power consumption design, the influence of temperature on equipment is fully considered in the design stage of the circuit board, the error caused by the temperature is reduced as much as possible, and the temperature distribution control is realized by the following method:

1) The heat dissipation capacity of the PCB directly contacted with the heating element is improved, and heat is conducted out through the PCB;

2) A radiator or a heat conduction pipe is added on the heating device, and a soft thermal phase change heat conduction pad is added on the surface of the device to improve the radiating effect and realize heat balance;

3) The heat dissipation is realized through the wiring design, and because the resin in the plate has poor heat conductivity, and the copper foil circuit and the hole are good conductors of heat, the improvement of the residual rate of the copper foil and the increase of the heat conduction hole are main means for heat dissipation;

4) The devices on the same printed board are arranged in a partition mode as much as possible according to the heat productivity and the heat dissipation degree of the devices, the devices with small heat productivity or poor heat resistance (such as small signal transistors, small-scale integrated circuits, electrolytic capacitors and the like) are placed at the uppermost stream (inlet) of the cooling airflow, and the devices with large heat productivity or good heat resistance (such as power transistors, large-scale integrated circuits and the like) are placed at the lowermost stream of the cooling airflow;

5) In the horizontal direction, the high-power device is arranged close to the edge of the printed board as much as possible so as to shorten the heat transfer path; in the vertical direction, the high-power devices are arranged close to the upper part of the printed board as much as possible, so that the influence of the devices on the temperature of other devices during working is reduced;

6) The heat dissipation of the printed board in the equipment mainly depends on air flow, so the air flow path needs to be researched during design, and devices or printed circuit boards need to be reasonably configured. Air always flows at a place with low resistance when flowing, so that a large air space is avoided in a certain area when devices are arranged on a printed circuit board. The configuration of a plurality of printed circuit boards in the whole machine also needs to pay attention to the same problem;

7) The device sensitive to the temperature is arranged in the area with the lowest temperature (such as the bottom of the equipment), and the arrangement of a plurality of devices is staggered on the horizontal plane as much as possible;

8) The concentration of hot spots on the PCB is avoided, the power is uniformly distributed on the PCB as much as possible, and the uniformity and consistency of the surface temperature performance of the PCB are kept. And in the design process, an area with too high power density is avoided, so that the influence of hot spots on the normal operation of the whole circuit is avoided.

For anti-interference, in order to reduce the interference of the external environment to the dynamic measurement unit to the maximum extent and ensure the collection of stable and effective data, the following anti-interference design is also made: the whole system adopts a single-point grounding mode, the integrity of the ground wire is ensured, and the grounding resistance is small enough; the signal transmission line adopts a specially customized oxygen-free copper wire, and the minimum measurement error is ensured by the same material; the signal transmission path adopts a high-quality cable and a connector.

As shown in fig. 4-6, in another example, each chassis is provided with a controller slot into which a plurality of acquisition boards can be inserted, and a chassis back plate with a synchronous trigger clock bus;

each pressure scanning valve assembly, each dynamic data acquisition assembly is configured to include:

the first FPGA I131 and the first FPGA II 231 are used for processing and outputting signals input by the signal conditioning circuit;

the first phase-locked loop PLL I132, the first phase-locked loop PLL II 232, the first clock management module I133, the first clock management module II 233, the CPU I134 and the CPU II 234 are in communication connection with the first FPGA;

the external communication interface I135, the communication interface II 235, the synchronous clock signal I136, the synchronous clock signal II 236, the synchronous trigger signal I137 and the synchronous trigger signal II 237 are in communication connection with the first clock management module I133, the first clock management module II 233, the CPU I134 and the CPU II 234 through a control bus I138 and a control bus II 238 which are matched with each other;

the control unit is configured to include:

the rack is provided with a front panel with a signal interface;

a second FPGA30 disposed inside the chassis;

a second phase-locked loop PLL31, a second clock management module 32, a synchronization signal generator 33, which are communicatively connected to the second FPGA;

the control unit is in communication connection with the pressure scanning valve assemblies and the dynamic data acquisition assemblies through a shunt, the overall structural design of the control unit adopts a 1U rack type structure, a signal interface is configured on a front panel and can be accessed to input and output signals, a synchronization module is in communication with an upper computer through a USB port, hardware equipment in the system adopts an embedded type structure based on FPGA, and the hardware structure based on FPGA and AD has high real-time performance meeting test conditions, so that the acquisition and storage of signals can be realized, and the advantages of strong synchronism, low power consumption, high reliability and the like are achieved; the control unit is used as an external trigger source and synchronously accessed to a plurality of acquisition terminals through a splitter to realize the layout of synchronous triggering of a plurality of devices;

each measuring unit of the scheme adopts a modular design, and the modules have independent functions and are not coupled. The modularized design is easy to expand the system capacity and improve the maintenance efficiency.

The FGPA realizes the operations of data acquisition, data processing, data transmission and the like in the FPGA through a standard PCIe interface. The method is divided into the following steps according to functions: the interface unit, the processing unit, the output unit and the like adopt a data flow driving mode, and after the data processing of the unit is completed, the data is packaged and sent to the next level, so that the data exchange is realized inside the framework.

The FPGA design elements comprise interface design, clock design, reset design, function design and the like. The interface design criteria are: excessive logic is not added, and the influence on the interface time sequence after the added logic is jammed is avoided; clocks include logic clocks, interface clocks, memory clocks, and the like. The logic clock depends on the key path of the logic, and the product performance is improved. When the FPGA realizes the synchronous signal time sequence, the synchronous adoption of the interface is realized by adopting a fixed and accurate interface clock. The memory clock realizes the data synchronous cache, and the data loss or instability caused by the refreshing frequency is avoided during the design; the internal reset of the FPGA comprises hard reset, logic reset, soft reset and the like. The hard reset is introduced into the external pin and is given in when the power is on, so that the whole FPGA reaches a stable state after the logic configuration is completed. The logic reset is generated by the internal logic of the FPGA and is used for setting the preparation state of signals such as synchronous control and the like. The soft reset is used in a debugging stage, and the soft reset is inserted into a point to be tested, a fault locating point and the like, so that the problem of segmentation can be quickly positioned, and the debugging speed is accelerated. The function design comprises the functions of signal acquisition, signal conditioning, synchronous control, data transmission and the like through the FPGA. The principle of functional design is stable and efficient, and the required circuit realization function and the constraint conditions for realizing the circuit, such as speed, power consumption, circuit type and the like, are comprehensively considered.

As shown in fig. 3, in another example, the system architecture of the software adopts a distributed network architecture, which is divided into 5 layers from bottom to top, and sequentially includes: the device comprises a signal layer, an acquisition layer, a transmission layer, a monitoring layer and a data layer. Specifically, the signal layer acquires various sensor signals arranged on the test bed and is used for acquiring various sensor signals of the tested test bed;

the acquisition layer consists of a steady-state pressure measurement system and a dynamic data acquisition system, can acquire and condition various sensor signals of the signal layer, and converts the acquired electric signals into upward transmitted acquisition data.

Furthermore, the collected data obtained by the collection layer is transmitted by the transmission layer through the Ethernet adopting the TCP/IP protocol, and the target of data transmission is the main control computer. The main control computer sends the acquisition instruction to the data acquisition equipment through the transmission layer.

The monitoring layer obtains real-time acquisition data through the transmission layer, the monitoring layer comprises a main control computer and a real-time acquisition function of matched software and can display the real-time acquisition data, and the monitoring layer provides a human-computer interaction interface.

The data layer is completed by system matching software, and the main functions are to manage the test data and analyze the test data. And realizing a multi-element comprehensive maintenance strategy combining the business processes to form an optimal guarantee strategy.

As shown in fig. 2, the basic functions of the data collection and preprocessing software include: user and authority management, parameter configuration, sensor field calibration, real-time acquisition and display of sensor signals, acquired data preprocessing, data playback and data export.

Specifically, the functions of the parameter configuration module mainly include:

the system parameter configuration comprises the configuration of system parameters such as sampling frequency, average point number, acquisition mode, synchronization and the like, and can be independently stored or loaded with configuration information.

The channel parameter configuration comprises configuration of parameters such as data type, data identification, range, filter type and cut-off frequency thereof, and can be independently stored or loaded with configuration information.

The output parameter configuration comprises configuration of parameters such as output format, output path, network transmission path and the like. The output configuration parameters can be stored independently, and the configuration information can also be loaded.

The test parameter configuration comprises configuration of parameters such as test names, model codes, model states, test train numbers and the like, and can be stored independently or loaded with configuration information.

The sensor field calibration function can perform zero calibration on a steady-state pressure sensor and also perform dynamic calibration on a dynamic sensor (a calibration source needs to be combined).

The real-time acquisition and display of the sensor signals is to acquire the real-time signals of the sensors and perform synchronous display and real-time analysis on the acquired data, and the real-time analysis algorithm comprises smoothing, filtering, amplitude analysis, frequency domain transformation, time-frequency analysis and the like. The real-time display includes test information display, data numerical value display, curve display and the like, and the real-time data can also be displayed in various forms, such as real-time waveforms, data headers, data lists and the like. The data of the real-time collected data can be selected to be synchronously stored, the stored data format is a TDMS file, the TDMS file can be used for subsequent signal preprocessing, data playback and other operations, and the TDMS file can be converted into files in other formats through a data export function.

The software has an external trigger function and can start or stop collecting data according to the external trigger. The triggering method comprises the following steps: network command triggering, TTL level triggering, manual click triggering, etc.

Three modes of continuous acquisition, step acquisition and manual acquisition can be selected during the independent test of the steady-state pressure and dynamic data acquisition; when steady-state pressure and dynamic data acquisition are performed simultaneously, a synchronous and continuous acquisition mode can be selected. For the characteristic information of the physical quantity acquired in real time, a real-time data (such as amplitude and frequency) distribution diagram of the physical signal corresponding to different key positions can be drawn according to the key positions in the component construction simulation diagram, wherein a line unit displays a one-dimensional line diagram, and a surface unit displays a two-dimensional cloud diagram.

The collected data preprocessing function can perform time domain and frequency domain post-processing analysis on the data stored in real time, and the signal analysis algorithm comprises the functions of smoothing, filtering, data interception, compression, deletion, additional storage, amplitude analysis, frequency domain transformation, time frequency analysis and the like. The method can automatically count various information such as the maximum value, the minimum value, the average value, the mean square value, the alternating current component, the direct current component, the fundamental frequency and the like of each channel. The data pre-processing may select different analysis algorithms and configuration parameters, for example the signal filter may select a Butterworth filter, a Chebyshev filter, an inverse Chebyshev filter, an eliptic filter, a Bessel filter, a Median filter, etc. For strain and temperature signals, the software can set parameters such as bridge configuration mode, temperature compensation, nonlinear compensation of bridge circuit, correction coefficient, attenuation compensation of long wire and the like.

The data playback function can set specific parameters during data playback, such as playback rate, playback data length, playback setpoint number and the like. When data is played back, the function of enlarging and reducing the curve is provided under the pause interface, and when the data is positioned on the curve, the XY coordinate value of the current point is displayed. When there are a plurality of curves, one curve can be arbitrarily selected. The data of two channels can be arbitrarily selected and freely combined into an X-Y curve graph. Real-time spectrum analysis can be carried out on the playback data, and a time domain curve and a spectrogram are synchronously displayed.

The above scheme is merely illustrative of a preferred example, and is not limiting. When the invention is implemented, appropriate replacement and/or modification can be carried out according to the requirements of users.

The number of apparatuses and the scale of the process described herein are intended to simplify the description of the present invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.

While embodiments of the invention have been disclosed above, it is not intended to be limited to the uses set forth in the specification and examples. It can be applied to all kinds of fields suitable for the present invention. Additional modifications will readily occur to those skilled in the art. It is therefore intended that the invention not be limited to the exact details and illustrations described and illustrated herein, but fall within the scope of the appended claims and equivalents thereof.

Claims (7)

1. A steady-state pressure and dynamic data phase synchronization parallel acquisition and preprocessing system is characterized by comprising:

at least one group of steady state pressure acquisition units for measuring the steady load of the aircraft model;

at least one group of dynamic data acquisition units for measuring the unsteady loads of the aircraft model;

the control unit is used for realizing the synchronization of the measurement data acquisition of the steady-state pressure acquisition unit and the dynamic data acquisition unit;

a terminal connected with the steady-state pressure acquisition unit and the dynamic data acquisition unit through a network switch and loaded with synchronous acquisition and preprocessing software;

wherein the phase synchronization is configured to include:

the method comprises the steps that in the same large class of acquisition units, the start and stop points of recorded data in all acquisition cards are determined through the case cascade connection and external common-frequency clock synchronous trigger control, and the synchronous acquisition among the acquisition units in the same large class is realized;

in any group of acquisition units, each measurement channel adopts an independent analog-digital converter (ADC), and synchronous acquisition of each channel is realized in one group of acquisition units through a back bus;

the method comprises the steps that starting and stopping points of recorded data in all acquisition cards are determined among different types of acquisition units through an external common-frequency clock and synchronous triggering, and synchronous timestamps are inserted into each group of data through a synchronous counter, so that synchronous acquisition of different types of data is realized.

2. The steady-state pressure and dynamic data phase-synchronized parallel acquisition and preprocessing system of claim 1, wherein each steady-state pressure acquisition unit is configured to comprise:

the pressure sensors are matched with the positions of the points to be measured on the gas path connecting assembly;

the first signal conditioning circuit is in communication connection with each pressure sensor to construct a corresponding measuring channel;

the pressure scanning valve assembly is in communication connection with each first signal conditioning circuit so as to realize synchronous acquisition of each pressure sensor;

the first chassis is used for integrating all the pressure scanning valve components, and a first controller with an operating system is arranged in the first chassis;

a pressure controller connected to each pressure scanning valve assembly to provide a standard pressure.

3. The steady-state pressure and dynamic data phase-synchronized parallel acquisition and pre-processing system of claim 2, wherein the dynamic data acquisition unit is configured to comprise:

the sensor comprises a plurality of types of sensors for collecting noise, vibration, temperature, strain and pulsating pressure related physical quantities;

the second signal conditioning circuit is in communication connection with each sensor to construct a corresponding measuring channel;

the dynamic data acquisition assembly is in communication connection with each second signal conditioning circuit to realize synchronous acquisition of each sensor;

and a second case for integrating the dynamic data acquisition assembly, wherein a second controller with an operating system is arranged in the second case.

4. The steady state pressure and dynamic data phase synchronization parallel acquisition and preprocessing system of claim 3, wherein each chassis is provided with a controller slot into which a plurality of acquisition boards can be inserted, and a chassis back plate with a synchronous trigger clock bus;

each pressure scanning valve assembly, each dynamic data acquisition assembly is configured to include:

the first FPGA is used for processing and outputting the signal input by the signal conditioning circuit;

the first phase-locked loop PLL is in communication connection with the first FPGA, the first clock management module and the CPU;

the external communication interface, the synchronous clock signal and the synchronous trigger signal are in communication connection with the first clock management module and the CPU through the control bus.

5. The steady-state pressure and dynamic data phase-synchronized parallel acquisition and pre-processing system of claim 1, wherein the control unit is configured to comprise:

the frame is provided with a front panel with a signal interface;

the second FPGA is arranged inside the rack;

the second phase-locked loop PLL is in communication connection with the second FPGA, the second clock management module and the synchronous signal generator;

the control unit is in communication connection with each pressure scanning valve assembly and each dynamic data acquisition assembly through a shunt.

6. The steady-state pressure and dynamic data phase synchronization parallel acquisition and preprocessing system of claim 1, wherein the system architecture of the software adopts a distributed network architecture, which is divided into 5 layers from bottom to top, and sequentially: the device comprises a signal layer, an acquisition layer, a transmission layer, a monitoring layer and a data layer.

7. The steady state pressure and dynamic data phase synchronized parallel acquisition and pre-processing system of claim 1, wherein the basic functions of the software include: user and authority management, parameter configuration, sensor field calibration, real-time acquisition and display of sensor signals, acquired data preprocessing, data playback and data export;

wherein the parameter configuration comprises:

the system parameter configuration comprises the configuration of sampling frequency, average point number, acquisition mode and whether system parameters are synchronized or not;

channel parameter configuration, including configuration of data type, data identification, range, filter type and cut-off frequency parameter;

the output parameter configuration comprises the configuration of the output format, the output path and the network transmission path parameter, and the output configuration parameter can be independently stored and can also be loaded with configuration information;

and test parameter configuration, which comprises configuration of test name, model code, model state and test train number parameters.

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