CN112278265B

CN112278265B - Phase angle processing logic in propeller synchronous control

Info

Publication number: CN112278265B
Application number: CN202011226642.5A
Authority: CN
Inventors: 周洁; 秦铭; 黄向华
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2020-11-05
Filing date: 2020-11-05
Publication date: 2023-09-12
Anticipated expiration: 2040-11-05
Also published as: CN112278265A

Abstract

The invention discloses phase angle processing logic in propeller synchronous control, belongs to the field of propeller synchronous control, and can be used for noise control of a propeller. The phase angle state of the current propeller is judged by comparing the command phase angle input by the system with the actual working phase angle of the propeller, the command information is processed, and the adjustment mode of the propeller phase angle is correspondingly output. By means of the phase angle characteristics of the multi-blade propeller, phase angle processing logic in the synchronous control of the propeller can optimize a control path of phase angle processing, reduce the cost of phase angle control and increase the speed of the phase angle of the controlled propeller reaching a command value.

Description

Phase angle processing logic in propeller synchronous control

Technical Field

The invention is used for phase angle processing in propeller synchronous control, relates to phase angle processing logic in propeller synchronous control, belongs to the field of propeller synchronous control, and can be used for noise control of a propeller.

Background

The aviation turboprop engine has the advantages of low fuel consumption, high single power, good speed characteristics and maneuverability and the like. Compared with engines such as turbojet fans, the air jet fan has the defects that the propellers directly rotate at high speed in the air to generate larger noise, and the multi-propeller aircraft generates large noise and vibration to the engine room due to the rotation of the multi-propellers. The internal noise level of the propeller aircraft is 85-105 dB, while the noise needs to be reduced by 25dB in order to reach the same internal noise level of the turbofan aircraft. The propeller synchronous control noise reduction utilizes the mutual offset of the existing sound sources, and the noise vibration generated by the original independent propellers is partially offset by controlling the set phase angle difference of a plurality of propellers of the multi-propeller aircraft, so that the effect of reducing the vibration and noise in the cabin is achieved.

Disclosure of Invention

The invention aims to optimize the phase angle processing process in the traditional propeller synchronous control, and provides phase angle processing logic in the propeller synchronous control. The phase angle processing logic can improve the speed of phase angle adjustment and reduce the cost of controlling the propeller to reach the instruction phase angle.

When the number of blades of the propeller is n, the phase angle range is from (180/n) ° to (180/n) °, and the angle of half the phase angle range, that is, (180/n) °, is defined as half the phase angle γ, and the processing logic of the phase angle is the same regardless of the number of blades. The input command phase angle is denoted as α, and the operating phase angle is denoted as β.

The specific process for judging the state of the current propeller phase angle is as follows: performing numerical calculation on the working phase angle and the instruction phase angle, and defining the phase angle state of the propeller as a state 1 when the phase angle of the |alpha-beta| is less than or equal to gamma; when α - β > γ, the phase angle state of the propeller is defined as state 2.

The specific process of the adjustment mode for processing the instruction information and outputting the propeller phase angle is as follows: and adopting a corresponding instruction processing mode according to the phase angle state. When the phase angle of the propeller is in a state 1, the phase angle of the propeller is adjusted according to a default control strategy, so that the phase angle of the slave reaches an instruction value, and the absolute value of the relative angular displacement is |alpha-beta|; when the phase angle of the propeller is in a state 2, the absolute value of the relative angular displacement is 2 gamma- |alpha-beta|, and the two conditions are divided according to the magnitude of the instruction phase angle and the working phase angle: if alpha is larger than beta, adopting a deceleration mode to continuously reduce the phase angle of the propeller until the phase angle exceeds the lower limit of the phase angle range, jumping to the upper limit of the range, and continuing decelerating until the command value is reached. And if alpha is less than or equal to beta, adopting an acceleration mode to lead the working phase angle to firstly exceed the upper limit of the phase angle range, jump to the lower limit of the phase angle range, and continue to accelerate until the phase angle of the propeller reaches the instruction value.

The invention has the obvious advantages that:

(1) Instruction logic optimizes the control path for the phase angle with less cost for phase angle control.

(2) The relative angular displacement of phase angle adjustment when the instruction phase angle is greatly different from the working phase angle is reduced, and the phase angle of the controlled propeller can reach the instruction phase angle more quickly.

Drawings

Fig. 1 is a graph of angular displacement versus phase angle.

In fig. 2 6, the command signal logic correction chart of the vane propeller is shown with the horizontal axis representing the command phase angle and the vertical axis representing the operating phase angle of the propeller.

Fig. 3 is a schematic block diagram of a phase angle state judgment and phase angle processing mode of the controlled propeller.

Detailed Description

The phase angle processing logic of the present invention is described in detail below in conjunction with fig. 1-3.

The synchronous control of the propellers is mainly characterized in that the synchronous control of phase angles of a plurality of propellers is realized, one engine is selected as a reference host, the rotation speed is kept constant, and other engines are slaves and follow the phase angles of the host to realize synchronous control. The slave needs to receive a phase angle control instruction, and the rotation speed is adjusted to enable the phase angle of the propeller to reach a preset value.

The angular displacement is the integral of the rotational speed, the phase angle is a non-linear angle describing the relationship between the plurality of propellers, and the relationship with the angular displacement is shown in figure 1. The phase angle range of a multi-bladed propeller is related to the number of blades thereof, and the phase angle range of a propeller of n blades is- (180/n) ° to (180/n) °. The existing phase angle processing logic is used for adjusting between the upper limit and the lower limit of a phase angle range, namely, the actual working phase angle is larger than the instruction phase angle, and decelerating is carried out to enable the working phase angle to reach the instruction value; otherwise, the acceleration adjustment phase angle reaches the instruction value. While in combination with fig. 1, it can be known that the phase angle is continuously increased near the upper limit of the phase angle, the phase angle jumps to the lower limit and then continuously increases from the lower limit; and the phase angle is continuously reduced near the lower limit of the phase angle, the phase angle can jump to the upper limit first and then is continuously reduced. The existing phase angle processing logic does not apply the characteristic, and when the working phase angle and the command phase angle are large, the relative angular displacement of the propeller of the slave machine reaching the preset phase angle is also large. It is highly necessary to optimize the conventional phase angle processing logic in terms of phase angle characteristics to reduce the control cost of propeller phase angle adjustment.

The phase angle processing logic of the present invention is applicable to phase angle processing of multi-bladed propellers. The method is the same regardless of the number of blades, and a 6-blade propeller will be described as an example.

(1) And judging the current state of the propeller phase angle. A propeller equipped with 6 blades has a phase angle ranging from-30 DEG to +30 deg. When the difference between the command phase angle and the working phase angle is less than or equal to 30 degrees, i.e., |alpha-beta|is less than or equal to 30 degrees, the phase angle state of the propeller is state 1, i.e., the area represented by the blank part in fig. 2. When the difference between the commanded phase angle and the operating phase angle is less than or equal to 30 °, i.e., |α - β| > 30 °, the phase angle state of the propeller is state 2, i.e., the region indicated by the shaded portion in fig. 2.

(2) As shown in fig. 3, when the phase angle state of the propeller is state 1, the phase angle is adjusted according to the conventional control logic, no phase angle jump occurs in the control process, the relative angular displacement is |α - β|, and the working phase angle is changed by increasing or decreasing the rotational speed of the propeller. If alpha is larger than beta, the phase angle of the propeller is continuously increased by acceleration until reaching a command value; otherwise, if alpha is less than or equal to beta, the phase angle of the propeller is continuously reduced by speed reduction until the instruction value is reached.

(3) As shown in fig. 3, when the phase angle of the propeller is in state 2, there is a phase angle jump in the control process, and the absolute value of the relative angular displacement is 60 ° - |α - β|, and the two types of phase angle jump are classified according to the magnitude of the instruction phase angle and the working phase angle: if alpha is larger than beta, adopting deceleration to continuously reduce the phase angle of the slave until the phase angle exceeds the lower limit of the phase angle range, jumping to the upper limit of the range, and continuing to decelerate until reaching the instruction value; otherwise, if alpha is less than or equal to beta, adopting an acceleration mode to lead the phase angle of the propeller to firstly exceed the upper limit of the phase angle range, jump to the lower limit of the range, and continue to accelerate until reaching the instruction value.

Claims

1. A phase angle processing logic system in propeller synchronous control, characterized by: comparing the instruction phase angle input by the system with the actual working phase angle of the propeller, judging the state of the current propeller phase angle, processing the instruction information and outputting the adjustment mode of the propeller phase angle;

the logic system judges the current state of the propeller phase angle by the following steps: regarding a propeller of n blades, the phase angle range is- (180/n) ° to (180/n) °, a half angle of the phase angle range is defined as a half angle, the state of the propeller phase angle when the difference between the working phase angle and the instruction phase angle is less than or equal to the half angle is defined as a state 1, and the state of the propeller phase angle when the difference between the working phase angle and the instruction phase angle is greater than the half angle is defined as a state 2;

the logic system is characterized in that the state 1 is a state that the phase angle does not jump in the control process, and the phase angle of the propeller is adjusted according to a default control strategy so that the phase angle of the propeller reaches an instruction value;

the logic system processes the instruction information and outputs the adjustment mode of the propeller phase angle, which is as follows: the state 2 is a state that the phase angle jumps in the control process, if the instruction phase angle is greater than the working phase angle, the phase angle of the propeller is continuously reduced in a speed reducing mode, and the speed is continuously reduced in a mode that the phase angle jumps from the lower limit to the upper limit so that the phase angle reaches the instruction value; otherwise, the instruction phase angle is less than or equal to the working phase angle, and the acceleration mode is adopted, and the acceleration is continued until the phase angle of the propeller reaches the instruction value in a mode that the phase angle jumps from the upper limit to the lower limit.