A Simplified Calibration Method for Flow Line Displacement Sensors of Aero-engines

Abstract

This application belongs to the field of aero-engine control systems, and particularly relates to a simplified calibration method for a flow line displacement sensor of an aero-engine. It includes: Step 1, adding a BIT value-voltage value calibration line in the digital electronic controller, and converting the voltage signal of the linear displacement sensor into a BIT value according to the BIT value-voltage value calibration line; Step 2, obtaining the voltage value collected by the digital electronic controller; Step 3, performing flow and valve mechanical displacement calibration through pump control accessories to obtain a flow-voltage value calibration line; Step 4, inputting the flow-voltage value calibration line into the digital electronic controller, and the digital electronic controller generates a flow-BIT value calibration line according to the BIT value-voltage value calibration line and the flow-voltage value calibration line. This application can reduce the workload of preparing for the aero-engine to be put on the test bench, save time and manpower, improve efficiency, and can also reduce the probability of errors occurring after re-calibration.

Description

Technical Field

[0001] This application belongs to the field of aero-engine control systems, and particularly relates to a simplified calibration method for a flow line displacement sensor of an aero-engine. Background Art

[0002] The calibration of an aero-engine control system is part of the preparatory work before bench testing and after installing the engine on the aircraft. According to the feedback from the delivery of aero-engines and their use in the field, users generally have strong opinions on the problems such as a large number of calibration parameters, long time consumption, and inconvenient operation in the bench and installation preparation work. The calibration of an aero-engine control system is a process of corresponding the physical quantities collected by each sensor of the engine with the BIT values (the BIT value is the digital quantity collected by the controller, also known as the code value, with the unit of BIT) collected by the digital electronic controller, so as to form the reference of each collected parameter of the control system. The purpose of calibrating the aero-engine control system is to determine the data reference of the digital electronic controller responsible for parameter collection in the engine test system. Since the collected values of each parameter of the controller are all digital signals (BIT values), in order to correspond the digital signals collected by the controller with the true physical meaning of the parameters (see Figure 1 ), it is necessary to calibrate the acquisition channels of the controller by adding analog sensor signals outside the controller, eliminate the differences between individual related accessories, and ensure the consistency of the system.

[0003] As a part of the test system, the linear displacement sensor for aero-engines is mainly used to measure the opening of the fuel flow metering valve. As the "eyes" of the digital electronic controller, it converts the displacement signal into a voltage signal and transmits it to the controller. The LVDT linear displacement sensor used in aero-engines generally consists of an iron core, an armature, a primary coil, and a secondary coil. There is a freely movable rod-shaped armature inside the coil. One end of the rod-shaped armature is connected to the fuel metering valve. When the metering valve moves, unequal induced electromotive forces will be generated in the two secondary coils, with a voltage output. Moreover, the magnitude of the voltage is proportional to the displacement. The voltage signal is transmitted to the controller for the control of the aero-engine. The circuit connecting the LVDT linear displacement to the controller consists of 5 signals, including 2 excitation signals, 2 feedback signals, and 1 common terminal grounding signal. The linear displacement sensor for aero-engines is generally installed in the pump control type accessories to measure the opening of the fuel flow metering valve, and then control the fuel flow of the aero-engine. When the pump control type accessories leave the factory, the digital electronic controller is used to collect the BIT value converted from the voltage value output by the linear displacement sensor to control the valve opening, and then the fuel flow calibration line is formed by comparing the fuel flow at this opening, that is, the corresponding relationship between the fuel flow and the valve opening (BIT value). Since a fixed digital electronic controller is used when the pump control type accessories leave the factory, and the digital electronic controller matched after installing the engine will inevitably change, the differences between the controllers will cause errors in the acquisition and conversion process. Therefore, after the pump control type accessories are installed on the engine, the relevant parameters collected by the linear displacement sensor need to be recalibrated, which is labor-consuming and time-consuming, and the calibration operation is inconvenient with a large workload, affecting the overall progress; when replacing the digital electronic controller, the relevant parameters collected by the flow linear displacement sensor need to be recalibrated; the calibration of the pump control type accessories installed on the engine has high technical requirements for operators. If the process is not familiar, errors are likely to occur, which will affect the overall control of the aero-engine.

[0004] Therefore, it is desirable to have a technical solution to overcome or at least mitigate at least one of the above-mentioned defects of the prior art. Summary of the Invention

[0005] The purpose of the present application is to provide a simplified calibration method for the flow linear displacement sensor of an aero-engine to solve at least one problem existing in the prior art.

[0006] The technical solution of the present application is as follows:

[0007] A simplified calibration method for the flow linear displacement sensor of an aero-engine, comprising:

[0008] Step 1: Add a BIT value - voltage value calibration line in the digital electronic controller, and convert the voltage signal of the linear displacement sensor into a BIT value according to the BIT value - voltage value calibration line;

[0009] Step 2: Obtain the voltage value collected by the digital electronic controller;

[0010] Step 3: Calibrate the flow rate and valve mechanical displacement through a pump adjustment type accessory to obtain a flow rate - voltage value calibration line;

[0011] Step 4: Input the flow rate - voltage value calibration line into the digital electronic controller, and the digital electronic controller generates a flow rate - BIT value calibration line according to the BIT value - voltage value calibration line and the flow rate - voltage value calibration line.

[0012] In at least one embodiment of the present application, in Step 1, the BIT value - voltage value calibration line includes a BIT value - VA voltage value calibration line and a BIT value - VB voltage value calibration line.

[0013] In at least one embodiment of the present application, in Step 2, the voltage values collected by the digital electronic controller include a VA voltage value and a VB voltage value.

[0014] In at least one embodiment of the present application, in Step 3, the flow rate - voltage value calibration line includes a flow rate - VA voltage value calibration line and a flow rate - VB voltage value calibration line.

[0015] The invention has at least the following beneficial technical effects:

[0016] The simplified calibration method for the flow line displacement type sensor of the aero - engine in the present application realizes that after the pump adjustment type accessory of the aero - engine is installed on the engine, the relevant parameters collected by the flow line displacement type sensor are no longer calibrated, reducing the workload of the aero - engine on - platform preparation, saving time and manpower, and improving efficiency; after replacing the digital electronic controller, the relevant parameters collected by the flow line displacement type sensor are no longer calibrated; reducing the dependence on the proficiency of calibration operators and reducing the probability of errors after re - calibration. Brief Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the role of calibration in the control system;

[0018] Figure 2 It is a schematic diagram of the calibration conversion relationship of the digital electronic controller in an embodiment of the present application. Detailed Embodiment

[0019] For the purpose of making the objectives, technical solutions, and advantages of the present application more clear, the following will describe in more detail the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The described embodiments are some, but not all, of the embodiments of the present application. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and should not be construed as a limitation to the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present application. The following will describe the embodiments of the present application in detail in conjunction with the accompanying drawings.

[0020] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying 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 a limitation to the scope of protection of the present application.

[0021] The following will further elaborate on the present application in conjunction with the attached Figure 2 drawings.

[0022] The present application provides a simplified calibration method for an aero-engine flow line displacement sensor, including the following steps:

[0023] Step 1: Add a BIT value-voltage value calibration line in the digital electronic controller, and convert the voltage signal of the linear displacement sensor into a BIT value according to the BIT value-voltage value calibration line. Among them, the BIT value-voltage value calibration line includes a BIT value-VA voltage value calibration line and a BIT value-VB voltage value calibration line;

[0024] Step 2: Obtain the voltage values collected by the digital electronic controller; among them, the voltage values collected by the digital electronic controller include VA voltage values and VB voltage values;

[0025] Step 3: Perform flow and valve mechanical displacement calibration through a pump control type accessory to obtain a flow-voltage value calibration line; among them, the flow-voltage value calibration line includes a flow-VA voltage value calibration line and a flow-VB voltage value calibration line;

[0026] Step 4: Input the flow rate - voltage value calibration line into the digital electronic controller. The digital electronic controller generates a flow rate - BIT value calibration line according to the BIT value - voltage value calibration line and the flow rate - voltage value calibration line. Specifically, input the flow rate - VA voltage value calibration line and the flow rate - VB voltage value calibration line into the digital electronic controller. The digital electronic controller generates a flow rate - BIT value calibration line according to the BIT value - voltage value calibration line, the flow rate - VA voltage value calibration line, and the flow rate - VB voltage value calibration line.

[0027] The simplified calibration method for the flow line displacement sensor of the aero - engine in this application is based on the principle of the digital electronic controller's handling of the LVDT circuit. By combining the BIT value - voltage value calibration line in the digital electronic controller with the voltage value and flow rate calibration line recorded at the factory of the pump control - type accessory, the purpose of simplifying the calibration of the flow line displacement sensor of the aero - engine is achieved.

[0028] The simplified calibration method for the flow line displacement sensor of the aero - engine in this application is as follows in the principle of the digital electronic controller's handling of the LVDT circuit. The LVDT linear displacement sensor converts the displacement of the fuel flow metering valve in the pump control into a voltage value and transmits it to the digital electronic controller. The digital electronic controller converts the voltage signal transmitted by the LVDT linear displacement sensor into a control - used BIT value. The principle of the digital electronic controller's handling of the LVDT circuit is as follows: The digital electronic controller internally integrates an internal oscillator and a voltage reference. Only a few peripheral passive components are required to complete the excitation and signal processing of the LVDT and directly output a DC voltage proportional to the displacement. The digital electronic controller generates a sine wave with a fixed frequency and fixed amplitude through an internal low - distortion sine oscillator. After amplification, it is used as an excitation signal to excite the primary coil of the LVDT, and then through the movable magnetic core, it is coupled to the two secondary coils connected in series of the LVDT, generating two sine waves (VA, VB) with the same frequency. There is a certain hard - connection relationship between the magnetic core of the LVDT and the mechanical displacement it senses. When the magnetic core undergoes displacement, the amplitudes of the sine waves coupled to the two secondary coils change, and the difference between VA and VB is proportional to the magnetic core displacement, that is, the displacement of the fuel flow metering valve in the pump control. According to the characteristic that (VA + VB) is a fixed value under normal use of the LVDT sensor, the digital electronic controller synchronously measures the difference in amplitudes between VA and VB and performs an operation of the difference ratio and sum of VA and VB inside, that is, the operation of (VA - VB) / (VA + VB). The operation result is filtered by a filter and then amplified through an operation to output a voltage proportional to the displacement. Due to the influence of component tolerances in the manufacturing process of the digital electronic controller, the conversion relationship between the output voltage of the LVDT linear displacement sensor by different controllers will be different.

[0029] Through the analysis of the principle of processing the LVDT circuit by a digital electronic controller, since there are differences in the acquisition values of the LVDT linear displacement sensor by different digital electronic controllers, simplifying the calibration process of linear displacement sensors is mainly based on the correction of the errors generated in the acquisition and conversion process by the digital electronic controller itself when it leaves the factory. The established calibration conversion relationship is shown in Figure 2 , where:

[0030] The positive direction of the X-axis represents the mechanical position and flow rate of the fuel flow metering valve of the engine pump control type accessory;

[0031] The negative direction of the X-axis represents the engine standard value (which can be voltage, bit value, dimensionless number, etc.);

[0032] The positive direction of the Y-axis represents the bit value collected by the newly replaced digital electronic controller;

[0033] The negative direction of the Y-axis represents the bit value collected by the original digital electronic controller.

[0034] Based on the above analysis, the simplified calibration method of the aero-engine flow linear displacement sensor of the present application obtains the simplified calibration process of the flow linear displacement sensor: 1) Add a BIT value - voltage value calibration line (i.e., the conversion relationship between VA and VB voltages and BIT) in each digital electronic controller, convert the voltage signal of the received linear displacement sensor into a BIT value according to the calibration line, and eliminate the errors caused by the hardware differences of the digital electronic controller; 2) Display the VA and VB voltage values collected by the digital electronic controller on the computer; 3) When calibrating the flow rate and the mechanical displacement of the valve of the pump control type accessory, record the corresponding relationship between the flow rate - VA and the flow rate - VB, that is, form the flow rate - VA and the flow rate - VB calibration lines; 4) Input the flow rate - VA and the flow rate - VB calibration lines into the digital electronic controller, and the controller internally combines the voltage value - BIT value calibration line to form a new flow rate - BIT calibration line.

[0035] After the implementation of the simplified calibration method of the aero-engine flow linear displacement sensor of the present application, it can replace the original calibration method, and the accuracy will not be reduced. It can realize that the calibration work of the flow linear displacement sensor is no longer carried out after the aero-engine is on the test bench or installed on the aircraft or the digital electronic controller is replaced. This method can not only reduce the workload of preparing for the aero-engine on the test bench, save time and manpower, improve efficiency, but also reduce the probability of errors after re-calibration, and can be applied in the simplified calibration of the aero-engine flow linear displacement sensor, and has good market application prospects.

[0036] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims described above.

Claims

1. A simplified calibration method for an aircraft engine flow line displacement sensor, characterized in that, Including: Step 1: Add a BIT value - voltage value calibration line in the digital electronic controller, and convert the voltage signal of the linear displacement sensor into a BIT value according to the BIT value - voltage value calibration line; Step 2: Obtain the voltage value collected by the digital electronic controller; Step 3: Perform flow rate and valve mechanical displacement calibration through a pump control type accessory to obtain a flow rate - voltage value calibration line; Step 4: Input the flow rate - voltage value calibration line into the digital electronic controller, and the digital electronic controller generates a flow rate - BIT value calibration line according to the BIT value - voltage value calibration line and the flow rate - voltage value calibration line.

2. The simplified calibration method for the flow line displacement sensor of an aeroengine according to claim 1, characterized in that In Step 1, the BIT value - voltage value calibration line includes a BIT value - VA voltage value calibration line and a BIT value - VB voltage value calibration line.

3. The simplified calibration method for the flow line displacement sensor of an aeroengine according to claim 2, characterized in that In Step 2, the voltage values collected by the digital electronic controller include a VA voltage value and a VB voltage value.

4. The simplified calibration method for the flow line displacement sensor of an aeroengine according to claim 3, wherein In Step 3, the flow rate - voltage value calibration line includes a flow rate - VA voltage value calibration line and a flow rate - VB voltage value calibration line.

Images