CN-121977788-A - Data calculation method suitable for rotary wing rotary balance

CN121977788ACN 121977788 ACN121977788 ACN 121977788ACN-121977788-A

Abstract

The invention discloses a data resolving method suitable for a rotor wing rotary balance, which belongs to the technical field of aero aerodynamic wind tunnel test and comprises the steps of statically calibrating the balance, acquiring an initial trigger phase through an azimuth encoder, calculating load according to a balance formula, correcting according to a calibration shafting, calculating a phase angle corresponding to an acquisition point by combining the initial trigger phase with each circle of acquisition point, converting a rotary coordinate load into a fixed coordinate load through rotary coordinate conversion, obtaining a rotor hub fixed coordinate system load through two-core distance conversion, and finally obtaining a rotor wing average load and a data spectrogram through filtering and Fourier conversion. According to the invention, a novel coaxial rotor table rotary balance data resolving method is constructed, the triggering and collecting phases are determined by means of a high-resolution azimuth encoder, and the high-resolution collection and conversion of the load are realized by combining the rotation coordinate conversion, so that the accuracy of test data is effectively improved.

Inventors

LIU XIANGNAN
LIU SHI
YANG ZHENG
YU WENKAI
GAO HONGBO
SHAO TIANSHUANG

Assignees

中国航空工业集团公司哈尔滨空气动力研究所

Dates

Publication Date: 20260505
Application Date: 20260409

Claims (8)

1. A data resolution method for a rotary-wing rotary balance, comprising the steps of: s1, completing static calibration of a rotary wing rotary balance, and obtaining a balance elastic angle and a balance calm calibration formula, wherein the positive direction of the set balance resistance is opposite to the X direction of a balance body axis; S2, mounting the calibrated rotary wing rotary balance to a rotary wing table, connecting a data acquisition system, and acquiring an initial trigger phase of the rotary wing table through an azimuth encoder of the rotary wing table; S3, acquiring balance static output under each test state, and calculating to obtain balance load under a balance calibration shafting based on the balance static calibration formula; S4, correcting an elastic angle of the balance load obtained in the step S3 based on a balance calibration shafting to obtain load data under a balance rotation coordinate system; s5, calculating to obtain phase angles corresponding to all acquisition points in one rotation circle of the rotary balance based on the initial trigger phase and the acquisition point number of each circle of the rotary balance; S6, converting the load data under the balance rotating coordinate system into a balance fixed coordinate system based on a rotating balance coordinate conversion formula to obtain the load data under the balance fixed coordinate system; s7, converting the load data under the balance fixed coordinate system into a hub fixed coordinate system based on a two-center distance conversion formula to obtain the load data under the hub fixed coordinate system, wherein the two-center distance is the distance from the center of the hub to the balance calibration center in the hub shafting; And S8, carrying out filtering processing on the load data under the fixed coordinate system of the hub, and then carrying out Fourier transformation on the filtered data to obtain the average load of the rotor wing under the fixed coordinate system of the hub and the harmonic load under different frequencies.
2. The method for resolving data suitable for rotary scales of rotary wings according to claim 1, wherein in step S2, the initial trigger phase of the rotary scales is obtained by an azimuth encoder of the rotary wings, and specifically comprises the following steps: s21, aligning a longitudinal mark of a laser mark line instrument with the positive resistance direction of the balance; s22, manually rotating the balance at a low speed along the direction consistent with the actual rotation direction of the rotor, restarting pulse counting of the encoder after the azimuth encoder generates a zero signal, continuing rotating the balance until the positive resistance direction of the balance is overlapped with the longitudinal marking of the laser marking instrument for the first time, and stopping rotating; s23, calculating the rotation angle of the balance in the process from zero position signal generation to balance resistance positive direction alignment of the laser marking by the azimuth encoder, wherein the calculation formula is as follows: Wherein, the To calculate the angle rotated by the encoder to generate a zero signal to the positive balance resistance direction aligned with the laser reticle, For the counting of the counter of the acquisition system, For the resolution of the azimuth angle of data acquisition, Collecting the number of points for each rotation of the balance for each rotation of 1 circle; s24, based on the rotation angle Calculating an initial trigger phase of the rotary balance The calculation formula is as follows: 。
3. the method for resolving data applicable to rotary-wing rotary balances according to claim 2, wherein in step S3, before collecting the static output of the balance in each test state, the method further comprises collecting the balance data of one rotation as a dynamic zero point in a low-speed rotation state of the rotary-wing table, wherein the rotation speed of the low-speed rotation state is not more than 30rpm.
4. A method for resolving data suitable for rotary-wing balances according to claim 3, characterized in that in step S4, the method for correcting the elastic angle of the balance load is divided into two types according to the calibration axis of the balance: if the balance is calibrated for the earth axis, then: ; if the balance is body axis alignment, then: ; Wherein, the 、、、、、 Respectively the drag force, the lifting force, the side standing, rolling moment, the torque and the pitching moment under the balance rotation coordinate system; 、、、、、 calibrating the lower resistance, lifting force, side standing, rolling moment, torque and pitching moment of a shafting for the balance respectively; 、、 the longitudinal direction, the heading direction and the transverse direction elastic angle of the balance are respectively.
5. The data resolving method for rotary balance according to claim 4, wherein in step S5, the calculation formula of the phase angle corresponding to each acquisition point in one rotation is: Wherein, the For azimuth angles corresponding to the i-th acquisition point per turn, i=1, 2, 3.
6. The method for calculating data suitable for use in a rotary balance according to claim 5, wherein the formula in step S6 is: Wherein, the 、、、、、 The drag force, the lifting force, the side standing, the rolling moment, the torque and the pitching moment are respectively under a balance fixed coordinate system.
7. The method for calculating data suitable for rotary balance according to claim 6, wherein the formula in step S7 is: Wherein, the , , , , , For the drag, lift, roll, torque and pitch moment under the hub shaft, L, H, W are the distances between the hub center and the balance calibration center in the hub shaft, respectively.
8. The method for calculating data suitable for rotary balance according to claim 1, wherein in step S8, the load data in the fixed coordinate system of the hub is filtered by a correlation filtering method.

Description

Data calculation method suitable for rotary wing rotary balance Technical Field The invention relates to a data resolving method suitable for a rotor wing rotary balance, and belongs to the technical field of aero-aerodynamic wind tunnel tests. Background In recent years, high speed has become one of the main developments of helicopters, wherein coaxial rigid rotor helicopters are the focus of research for high speed helicopters. The development of coaxial rigid rotor aerodynamic performance test by using a rotor table is a main means for researching the aerodynamic performance of the coaxial rigid rotor. In order to realize independent measurement of pneumatic performance of the upper rotor wing and the lower rotor wing, the rotor wing platform is generally divided into two types of split type and integral type, the traditional integral type adopts a box balance to measure, the measurement accuracy is reduced because the upper rotor wing is far away from the balance, the generated moment is large, the structure of the rotor wing platform is simplified, the measurement accuracy is improved, the rotor wing balance on the novel coaxial rotor wing platform adopts a rotary balance to measure rotor wing force, moment and torque, and the load measurement result of the rotary balance is load data under a rotary coordinate system. Therefore, a corresponding resolving method is needed to be established to convert the load in the rotating coordinate system to the hub fixed coordinate system, so as to obtain the high-precision pneumatic load of the upper rotor wing. Disclosure of Invention The invention aims to solve the problems that the load of a rotating coordinate system measured by a rotor rotating balance on a novel coaxial rotor platform is difficult to convert into a fixed coordinate system of a hub, and the traditional measuring mode has a complex structure and low measuring precision, and provides a data resolving method suitable for the rotor rotating balance. The technical scheme of the invention is as follows: a data resolution method for a rotary-wing rotary balance, comprising the steps of: s1, completing static calibration of a rotary wing rotary balance, and obtaining a balance elastic angle and a balance calm calibration formula, wherein the positive direction of the set balance resistance is opposite to the X direction of a balance body axis; S2, mounting the calibrated rotary wing rotary balance to a rotary wing table, connecting a data acquisition system, and acquiring an initial trigger phase of the rotary wing table through an azimuth encoder of the rotary wing table; S3, acquiring balance static output under each test state, and calculating to obtain balance load under a balance calibration shafting based on the balance static calibration formula; S4, correcting an elastic angle of the balance load obtained in the step S3 based on a balance calibration shafting to obtain load data under a balance rotation coordinate system; s5, calculating to obtain phase angles corresponding to all acquisition points in one rotation circle of the rotary balance based on the initial trigger phase and the acquisition point number of each circle of the rotary balance; S6, converting the load data under the balance rotating coordinate system into a balance fixed coordinate system based on a rotating balance coordinate conversion formula to obtain the load data under the balance fixed coordinate system; s7, converting the load data under the balance fixed coordinate system into a hub fixed coordinate system based on a two-center distance conversion formula to obtain the load data under the hub fixed coordinate system, wherein the two-center distance is the distance from the center of the hub to the balance calibration center in the hub shafting; And S8, carrying out filtering processing on the load data under the fixed coordinate system of the hub, and then carrying out Fourier transformation on the filtered data to obtain the average load of the rotor wing under the fixed coordinate system of the hub and the harmonic load under different frequencies. Specifically, in the step S2, an initial trigger phase of the rotary balance is obtained through an azimuth encoder of the rotary wing table, and the method specifically comprises the following steps of S21, aligning a longitudinal marking of a laser marking instrument with a positive resistance direction of the balance; s22, manually rotating the balance at a low speed along the direction consistent with the actual rotation direction of the rotor, restarting pulse counting of the encoder after the azimuth encoder generates a zero signal, continuing rotating the balance until the positive resistance direction of the balance is overlapped with the longitudinal marking of the laser marking instrument for the first time, and stopping rotating; s23, calculating the rotation angle of the balance in the process from zero position signal generation to balance resistance posi