Networked airborne acquisition equipment

Abstract

The embodiment of the present specification provides a networked airborne acquisition device, including: a core main control module, which is used to control the current working mode through a Zynq processor, use FPGA to realize the control of ADC signal acquisition and the design of DAC calibration signal generation logic, use ARM to combine DAC calibration signal to fit the original value of ADC signal acquisition data according to a specific algorithm to generate a calibration curve, and store the coefficients of each power term of the calibration curve as correction information; when it is necessary to correct the ADC signal acquisition data and output it, bring the ADC signal acquisition data into the calibration curve polynomial restored by the correction information to generate a correction value, and generate and send three network packets of "original value, correction value, original value + correction information" inside the core main control module; a calibration control module, which is used to switch the working mode by controlling the internal electronic switch to turn on and off the ADC acquisition module and the DAC calibration signal generation module under the control of the core main control module; an ADC acquisition module, which is used to perform normal ADC signal acquisition; and a DAC calibration signal generation module, which is used for the DAC calibration signal generation logic to generate a DAC calibration signal.

Description

Technical Field

[0001] This document relates to the field of high-precision calibration and acquisition technology in the field of civil aircraft flight testing, and in particular to a networked airborne acquisition device. Background Art

[0002] With the continuous development of civil aviation airborne test technology, the degree of automation of the test system has become the biggest concern. Testers require that the test system can meet the test of all components under test and that the operation method is simple and operable. In the airborne test scenario, since aviation testing itself has high requirements for measurement accuracy, the periodic calibration of the acquisition channel in the test system consumes a lot of manpower and time costs. The disassembly and assembly of the acquisition equipment will affect the implementation progress of the test flight mission. In addition, the calibration itself has strict requirements on the external excitation signal, and the calibration of the acquisition equipment installed in a small space is more difficult.

[0003] At present, the acquisition systems in the test system mostly use the "processor + AD chip" architecture to complete data acquisition. The internal reference signal is generally the reference end of the AD chip, which is used for zero adjustment or self-test. The design of the internal integrated high-precision signal reference is generally implemented using a programmable high-precision operational amplifier. Generally, the adjustable range is narrow and it is not suitable for scenarios where the acquisition channel range is variable, and it cannot meet the needs of arbitrary point calibration or dynamic calibration.

[0004] In the field of flight testing, the traditional networked airborne acquisition system generally outputs acquisition data network packets that can output original acquisition values ​​or corrected values ​​after internal fitting and smoothing filtering. The network data packet structure does not contain correction information. Users cannot verify whether the correction method is reasonable, nor can they write the calibration parameters during use. The accuracy of the acquisition channel gradually decreases over time, and the acquisition accuracy can only be ensured through secondary processing at the processing end. The system has poor self-recovery capabilities. Summary of the invention

[0005] The purpose of the present invention is to provide a networked airborne acquisition device, aiming to solve the above-mentioned problems in the prior art.

[0006] The present invention provides a networked airborne acquisition device, which communicates with a control computer via Ethernet and realizes remote configuration, and the device specifically includes:

[0007] The core main control module is used to control the current working mode through the Zynq processor, use FPGA to realize the control of ADC signal acquisition and the logic design of DAC calibration signal generation, use ARM combined with DAC calibration signal to fit the original value of ADC signal acquisition data according to a specific algorithm to generate a calibration curve, and store the coefficients of each power term of the calibration curve as correction information; when the ADC signal acquisition data needs to be corrected and output, the ADC signal acquisition data is brought into the calibration curve polynomial restored by the correction information to generate a correction value, and the core main control module generates and sends three network packets of "original value, correction value, original value + correction information" inside;

[0008] A calibration control module connected to the core main control module, used to switch the working mode by controlling an internal electronic switch to turn on and off the ADC acquisition module and the DAC calibration signal generation module under the control of the core main control module;

[0009] An ADC acquisition module, connected to the core main control module and the calibration control module, for performing normal ADC signal acquisition;

[0010] The DAC calibration signal generating module is connected to the core main control module and the calibration control module, and is used for the DAC calibration signal generating logic to generate a DAC calibration signal.

[0011] By adopting the embodiment of the present invention, a networked airborne acquisition device is provided, which can realize automatic calibration inside the device and can correct the collected data in real time. The device adopts an internal high-precision reference source to provide a reference voltage, and uses the advantages of DAC to generate a series of calibration signals. The signal amplitude and frequency are adjustable. Compared with the solution of using a programmable operational amplifier device to realize a fixed calibration signal, it has stronger versatility and realizes a certain degree of continuous adjustment. It has an Ethernet interface and can be integrated in an existing airborne test environment. By controlling the computer configuration, it can also be used as an external calibration source, and can also be conveniently used for third-party organizations to trace the internal calibration source. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0013] Figure 1 is a schematic diagram of a networked airborne acquisition device according to an embodiment of the present invention;

[0014] Figure 2 It is a schematic diagram of a preferred structure of a networked airborne acquisition device according to an embodiment of the present invention;

[0015] Figure 3 is a schematic diagram of a calibration process according to an embodiment of the present invention;

[0016] Figure 4 is a schematic diagram of the collection and output process of an embodiment of the present invention;

[0017] Figure 5 It is a schematic diagram of an implementation of an embodiment of the present invention in an airborne test system. DETAILED DESCRIPTION

[0018] In order to solve the problems in the prior art, the embodiment of the present invention provides a networked airborne acquisition device with a Zynq processor as the core that supports internal self-calibration and error correction. It can generate a calibration sequence of any point according to the measurement range of the acquisition channel, complete the internal automatic calibration of the acquisition circuit, and at the same time, the calibration correction information can be written into the non-volatile memory inside the device, and can also be transmitted to the real-time processing device as correction information through the network packet of the airborne acquisition device output data. Combined with the need for periodic calibration of the acquisition channel during the actual test flight, the acquisition device can automatically calibrate its acquisition channel online when installed on the aircraft, and at the same time perform data calibration transmission, which can ensure that the accuracy of the collected data always meets the requirements, extend the service life of the equipment, and improve its working stability.

[0019] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the following will be combined with the drawings in one or more embodiments of this specification to clearly and completely describe the technical solutions in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this document.

[0020] According to an embodiment of the present invention, a networked airborne acquisition device is provided. Figure 1 Schematic diagram of a networked airborne acquisition device according to an embodiment of the present invention. Figure 1 As shown, the networked airborne acquisition device according to an embodiment of the present invention specifically includes:

[0021] The core main control module 10 is used to control the current working mode through the Zynq processor, use FPGA to realize the control of ADC signal acquisition and the logic design of DAC calibration signal generation, use ARM combined with DAC calibration signal to fit the original value of ADC signal acquisition data according to a specific algorithm to generate a calibration curve, and store the coefficients of each power term of the calibration curve as correction information; when the ADC signal acquisition data needs to be corrected and output, the ADC signal acquisition data is brought into the calibration curve polynomial restored by the correction information to generate a correction value, and the core main control module generates and sends three network packets of "original value, correction value, original value + correction information" inside; wherein, the data output format of the network packet specifically includes: original value, correction value, original value + correction information, or error information.

[0022] The core main control module 10 is specifically used for:

[0023] In the internal self-calibration mode, the configuration information set by the user through the control computer is obtained, and the configuration information is stored in the non-volatile memory. At the beginning of self-calibration, a series of calibration points are generated according to the calibration range in the configuration information, and the calibration control module is controlled to switch to the internal self-calibration mode; the DAC calibration signal and ADC signal acquisition data are obtained, and the acquisition error is judged. If it is a normal acquisition value, the calibration point is continuously stimulated and acquired to complete the calibration process, and the correction information is generated after the fitting curve is generated internally; if it is an error message, the error message is directly saved as the calibration result. After the self-calibration of all channels is completed, the test flight acquisition task is carried out normally. Among them, the configuration information specifically includes: calibration range, number of calibration points and number of cycles.

[0024] In the calibration output mode, the configuration information set by the user through the control computer is obtained and stored in the non-volatile memory. When the calibration output starts, a series of calibration points are generated according to the calibration range in the configuration information, and the calibration control module is controlled to switch to the calibration output mode, and the DAC calibration signal generated by the DAC calibration signal generation module is used as a calibration source to provide a signal to the outside.

[0025] The calibration control module 12 is connected to the core main control module and is used to switch the working mode by controlling the internal electronic switch to turn on and off the ADC acquisition module and the DAC calibration signal generation module under the control of the core main control module; wherein the working mode specifically includes: a "calibration output mode" in which the DAC calibration signal is output and the normal ADC signal is acquired, an "acquisition mode" in which the DAC calibration signal is not output and the normal ADC signal is acquired, and an "internal self-calibration mode" in which the DAC calibration signal is internally output to the acquisition end. The calibration control module 12 includes two electronic switches, which are respectively connected to the ADC acquisition module 14 and the DAC calibration signal generation module 16, and the ADC acquisition module 14 and the DAC calibration signal generation module 16 are controlled to be turned on and off by the electronic switches, wherein the control signal of the electronic switch is given by the core main control module.

[0026] The ADC acquisition module 14 is connected to the core main control module and the calibration control module for performing normal ADC signal acquisition; the ADC acquisition module 14 is used to select a high-precision reference source voltage range to match the ADC signal acquisition range.

[0027] The DAC calibration signal generation module 16 is connected to the core main control module and the calibration control module, and is used for the DAC calibration signal generation logic to generate a DAC calibration signal. The accuracy of the DAC calibration signal generation module 16 is greater than the accuracy of the ADC acquisition module 14. The DAC calibration signal generation module 16 is specifically used to ensure the frequency requirement of the dynamic DAC calibration signal through the voltage conversion time of the DAC.

[0028] The above technical solution of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings.

[0029] like Figure 2 As shown, an embodiment of the present invention provides a networked airborne acquisition device with a Zynq processor as the core that supports internal self-calibration and error correction. The device can generate a calibration sequence of any point according to the measurement range of the acquisition channel, complete the internal automatic calibration of the acquisition circuit, and at the same time, the calibration correction information can be written into the internal non-volatile memory of the device, and can also be transmitted to the real-time processing device as correction information through the network packet of the airborne acquisition device output data.

[0030] In the actual system structure, the networked airborne acquisition device (this case) is composed of a core main control module, a calibration control module, an ADC acquisition module, and a DAC calibration signal generation module. It communicates with the control computer through Ethernet and together with other networked acquisition devices constitutes a networked airborne acquisition system. The original value and correction information collected by the networked airborne acquisition device (this case) can be transmitted to the real-time processing device through Ethernet, so that the real-time processing device can obtain the original value or calculate the correction value. The correction value can also be directly output through Ethernet. At this time, the network packet does not contain the correction information.

[0031] The core main control module is a basic peripheral circuit based on the Zynq processor. FPGA is used to realize the ADC acquisition and DAC calibration signal generation logic design. ARM is used to combine the DAC calibration signal to fit the original value of the ADC signal acquisition data according to a specific algorithm to generate a calibration curve. The coefficients of each power term of the calibration curve are stored as correction information. The user can pre-configure the network packet data output mode through the control computer: original value, corrected value, original value + correction information. The generation of network packets is completed in the core main control module; the calibration control module is used to switch between three working modes: 1. calibration output mode (calibration signal output + normal acquisition), 2. acquisition mode (calibration signal no output + normal acquisition), 3. internal self-calibration mode (calibration signal internally output to the acquisition end); the ADC acquisition module is used for normal signal acquisition; the DAC calibration signal generation module is mainly used for data source generation based on a high-precision reference source and based on the calibration algorithm design.

[0032] Working Mode:

[0033] The acquisition mode is a normal function of the airborne acquisition system and will not be described in detail here.

[0034] When the present invention works in the internal self-calibration mode, its specific calibration flow chart is as follows: Figure 3 As shown. Before each test task is changed, the user sets the signal range, sampling rate, allowed accuracy, etc. of the acquisition through the control computer, and then the configuration information is stored in the non-volatile memory of the device. When the self-calibration starts, the device generates a series of calibration points according to the signal range in the configuration information. The number of calibration points can be manually modified, and the default is 11 points. After that, the analog switch is switched to the internal self-calibration mode (the default is the acquisition mode), and the calibration signal is generated by the DAC calibration signal generation module and collected by the ADC acquisition module. The acquisition error is judged. If it is a normal acquisition value, the calibration point is continuously stimulated and collected. The calibration process is completed according to the number of cycles required, and the correction information is generated after the internal fitting calibration curve is generated; if it is an error message, the error message is directly saved as the calibration result. After all channels are self-calibrated, the test flight acquisition task is carried out normally.

[0035] When the device of the embodiment of the present invention works in the calibration output mode, the DAC calibration signal generation module is used as a calibration source to provide a signal to the outside for calibrating other airborne acquisition devices or for third-party measurement. At this time, the calibration sequence is generated according to the configuration information input by the control computer, and the process is consistent with the normal calibration process, which will not be described in detail here.

[0036] Data output format introduction

[0037] The networked airborne acquisition equipment outputs the collected data in the form of network streams. The user-available data segments of the application layer are in the TLV format. The main data formats are as follows:

[0038] (1) Does not include correction information

[0039]

[0040] (2) Contains correction information

[0041]

[0042] km is the correction information, which varies according to the fitting formula. Generally, linear fitting calibration includes two parameters, k1 and k2. The message containing the correction information is sent at least once after the self-calibration is completed, and can be distinguished from other types of data by the Part ID number.

[0043] (3) Error message

[0044] This data message is universal and can transmit various error information through the TCP protocol, including calibration error information. The error code is 2 bytes.

[0045]

[0046] The collection and output process is as follows: Figure 4 As shown, depending on the different network output content, the collected value needs to be selected whether to be corrected before entering the network packet sending buffer.

[0047] In the actual design process of the embodiment of the present invention, the feasibility of the internal automatic calibration is ensured by taking the following measures:

[0048] 1. Select a high-precision reference source voltage range that matches the acquisition range of the device when it is working;

[0049] 2. The DAC bit number should be more than 20 to ensure that its application range is wide enough;

[0050] 3. Ensure the dynamic calibration signal frequency requirement through the DAC voltage conversion time;

[0051] 4. To ensure the accuracy of calibration, the accuracy of DAC is much greater than that of ADC.

[0052] The implementation method of the device of the embodiment of the present invention in the airborne test system is as follows: Figure 5 As shown, the networked acquisition device is connected to the airborne acquisition network system and allocated to a subnet with other networked airborne collectors. When the acquisition channel needs to be calibrated, the calibration range, calibration points and number of cycles are imported by configuring the software on the computer to start the internal automatic calibration process. After completion, the calibration information is generated to facilitate subsequent corrections or output to a third-party processing device through a network packet.

[0053] The beneficial effects of the embodiments of the present invention are as follows:

[0054] 1. The internal automatic calibration and real-time error correction method of the embodiment of the present invention has high versatility, and the design of the internal DAC calibration signal generation module enables it to be more widely and flexibly applied in high-precision acquisition systems;

[0055] 2. Combined with the design of network output, it can be applied in the current civil aviation test field and integrated into the network test system;

[0056] 3. Multiple data output modes support users to retain complete original data, ensuring the authenticity of the data. At the same time, they support real-time processing equipment to perform real-time error correction on the original data to improve data measurement accuracy;

[0057] 4. The internal calibration signal can be output to provide external calibration signals, and at the same time facilitate the third-party verification agency to measure the accuracy of the calibration signal;

[0058] 5. Meet the online calibration requirements of the airborne use environment, and complete the channel automatic calibration without plugging in and out the acquisition cable and external calibration source.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A networked airborne acquisition device, characterized in that: The device communicates with the control computer through Ethernet and realizes remote configuration. The device specifically includes: The core main control module is used to control the current working mode through the Zynq processor, use FPGA to realize the control of ADC signal acquisition and the logic design of DAC calibration signal generation, use ARM to combine the DAC calibration signal to fit the original value of ADC signal acquisition data according to a specific algorithm to generate a calibration curve, and store the coefficients of each power term of the calibration curve as correction information; when the ADC signal acquisition data needs to be corrected and output, the ADC signal acquisition data is brought into the calibration curve polynomial restored by the correction information to generate a correction value, and the core main control module generates and sends three network packets of "original value, correction value, original value + correction information" inside; A calibration control module connected to the core main control module, used to switch the working mode by controlling the internal electronic switch to turn on and off the ADC acquisition module and the DAC calibration signal generation module under the control of the core main control module; An ADC acquisition module, connected to the core main control module and the calibration control module, for performing normal ADC signal acquisition; The DAC calibration signal generating module is connected to the core main control module and the calibration control module, and is used for the DAC calibration signal generating logic to generate a DAC calibration signal.

2. The device according to claim 1, characterized in that The data output format of the network packet specifically includes: original information, revised information, original information+revised information, or error information.

3. The device according to claim 1, characterized in that The working modes specifically include: a "calibration output mode" in which the DAC calibration signal is output and the normal ADC signal is collected, an "acquisition mode" in which the DAC calibration signal is not output and the normal ADC signal is collected, and an "internal self-calibration mode" in which the DAC calibration signal is internally output to the collection end.

4. The device according to claim 3, characterized in that The core main control module is specifically used for: In the internal self-calibration mode, the configuration information set by the user through the control computer is obtained and stored in the non-volatile memory. When the self-calibration starts, a series of calibration points are generated according to the calibration range in the configuration information, and the calibration control module is controlled to switch to the internal self-calibration mode; Obtain DAC calibration signal and ADC signal acquisition data, determine acquisition error, and if it is a normal acquisition value, continuously stimulate and acquire calibration points to complete the calibration process, generate a fitting curve internally, and then generate correction information; If it is an error message, the error message will be directly saved as the calibration result. After all channels are self-calibrated, the test flight collection task will be carried out normally.

5. The device according to claim 3, characterized in that The core main control module is specifically used for: In the calibration output mode, the configuration information set by the user through the control computer is obtained and stored in the non-volatile memory. When the calibration output starts, a series of calibration points are generated according to the calibration range in the configuration information, and the calibration control module is controlled to switch to the calibration output mode, and the DAC calibration signal generated by the DAC calibration signal generation module is used as a calibration source to provide a signal to the outside.

6. The device according to claim 4 or 5, characterized in that The configuration information specifically includes: calibration range, calibration points and cycle times.

7. The device according to claim 1, characterized in that The accuracy of the DAC calibration signal generating module is greater than the accuracy of the ADC acquisition module.

8. The device according to claim 1, characterized in that The ADC acquisition module is used to select a high-precision reference source voltage range to match the ADC signal acquisition range.

9. The device according to claim 1, characterized in that The DAC calibration signal generation module is specifically used to ensure the frequency requirement of the dynamic DAC calibration signal through the voltage conversion time of the DAC.

10. The device according to claim 1, characterized in that The calibration control module includes two electronic switches, which are respectively connected to the ADC acquisition module and the DAC calibration signal generation module, and the connection and disconnection of the ADC acquisition module and the DAC calibration signal generation module are controlled by the electronic switches.

Images