阅读说明：本技术 一种确定伺服作动器长度变化的方法 (Method for determining length change of servo actuator ) 是由 马玉海 吴炜平 廉洁 张霞 刘凯 袁春贵 杨毅强 于 2020-04-03 设计创作，主要内容包括：本申请公开了一种确定伺服作动器长度变化的方法,具体包括以下步骤：在摆动中心处建立与箭体结构坐标系平行的坐标系；在坐标系中确定摆动中心与伺服作动器之间的各支点矢量；确定各支点矢量在坐标系中的坐标向量；根据各支点矢量的坐标向量确定两伺服作动器的长度变化。本申请能够根据推力矢量实时需求的两通道偏转角度指令,以及预设的悬挂几何尺寸常量,给出所需两伺服作动器的精确长度变化。(The application discloses a method for determining length change of a servo actuator, which specifically comprises the following steps: establishing a coordinate system parallel to the arrow structure coordinate system at the swing center; determining each pivot vector between the swing center and the servo actuator in a coordinate system; determining coordinate vectors of the pivot vectors in a coordinate system; and determining the length change of the two servo actuators according to the coordinate vector of each pivot point vector. The two-channel deflection angle instruction that this application can be based on the real-time demand of thrust vector to and the geometrical dimension constant that hangs that predetermines, give two required servo actuator's accurate length change.)

1. A method of determining a change in length of a servo actuator, comprising the steps of:

establishing a coordinate system parallel to the arrow structure coordinate system at the swing center;

determining each pivot vector between the swing center and the servo actuator in a coordinate system;

determining coordinate vectors of the pivot vectors in a coordinate system;

and determining the length change of the two servo actuators according to the coordinate vector of each pivot point vector.

2. The method of determining a change in length of a servo actuator of claim 1 wherein the coordinate vector of any vector in the coordinate system is denoted as r, r-r_xr_yr_z]^TWherein r is_xRepresenting coordinates in the X-axis of the coordinate system, r_yRepresenting coordinates on the Y-axis of the coordinate system, r_zDenotes the coordinates on the Z-axis of the coordinate system and T denotes the transpose of the matrix.

3. The method of determining a change in length of a servo actuator of claim 2, wherein the servo actuators include a pitch servo actuator and a yaw servo actuator.

4. A method of determining a change in length of a servo actuator as claimed in claim 3 wherein the upper pivot point at which the pitch servo actuator is articulated to the arrow structure is defined as a₁And a lower fulcrum hinged to the nozzle is defined as B₁(ii) a An upper supporting point of the yaw servo actuator hinged with the arrow body structure is defined as A₂The lower fulcrum articulated with the nozzle definingIs B₂；

Each pivot vector includes: from the centre of oscillation to an upper fulcrum A₁、A₂From the upper supporting point vector, the swing center to the lower supporting point B₁、B₂A lower fulcrum vector of (2);

wherein the upper pivot point vector r_E1Upper support point vector r_E2Lower fulcrum vector r_R1And a lower fulcrum vector r_R2The coordinate vectors in the coordinate system are specifically represented as:

wherein x is_pThe amount of sinking of the swing center during operation of the engine can be expressed as a function of the operating pressure P, where x_p(p); h is x_pWhen the swing center reaches the upper supporting point A when the swing center is 0₁Or upper fulcrum A₂Positive X-axis direction distance; e is from the swing center to the upper supporting point A₁From the negative Y-axis direction of (a), or the center of oscillation O to the upper fulcrum A₂Negative Z-axis distance; r is from the swing center O to the lower fulcrum B₁To the lower fulcrum B, or the center of oscillation O₂L is the swing center o to the lower fulcrum B₁Or lower fulcrum B₂The positive X-axis direction distance of (a) is a constant related to the nozzle suspension geometry.

5. The method of determining a change in length of a servo actuator according to claim 4, wherein determining a change in length of two servo actuators based on the coordinate vector of each pivot point vector comprises the sub-steps of:

determining a synthetic swing angle;

determining a coordinate vector of a unit vector of the central shaft of the spray pipe in a coordinate system according to the synthetic pivot angle;

determining a unit vector value along the direction of the synthetic rotating shaft according to the coordinate vector of the unit vector of the central shaft of the spray pipe in the coordinate system;

and determining the length change of the two servo actuators according to the unit vector value on the synthetic rotating shaft.

6. The method of determining a change in length of a servo actuator of claim 5 wherein the resultant pivot angle Φ is specified as:

wherein₁，₂Is the pivot angle of the two channels of the servo actuator.

7. The method of determining a change in length of a servo actuator of claim 5 wherein the unit vectors for the nozzle center axis include unit vectors before and after oscillation of the nozzle center axis, and wherein coordinate vectors in the coordinate system for the unit vectors u and u' for the nozzle center axis before and after oscillation are respectively represented as:

wherein phi is a synthetic swing angle,₁，₂is the swing angle of the two channels.

8. The method of determining a change in length of a servo actuator of claim 7 wherein the unit vector magnitude in the direction of the composite axis of rotationThe concrete expression is as follows:

and u' are unit vectors of the central shaft of the spray pipe positioned at the zero position before swinging and after swinging respectively.

9. The method of determining a change in length of a servo actuator of claim 5, further comprising, prior to determining a change in length of both servo actuators, calculating a pivot angle₁，₂At a certain value, the swing center o goes to the lower fulcrum B₁、B₂The specific value of the lower fulcrum vector of (2);

wherein the centre of oscillation o goes to the lower fulcrum B₁、B₂The specific values of the lower fulcrum vector of (2) are expressed as:

wherein r is_R1Is a swing angle₁，₂Zero swing center o to lower fulcrum B₁Lower support point vector of r_R2Is a swing angle₁，₂Zero-time swing center O to lower fulcrum B₂The lower-fulcrum vector of (a) is,is a unit vector value along the direction of the synthetic rotating shaft, and phi is a synthetic swing angle.

10. The method of determining a change in length of a servo actuator of claim 9, wherein two servo actuator changes in length x_r1、x_r2The concrete expression is as follows:

x_r1＝|r′_R1-r_E1|

x_r2＝|r′_R2-r_E2|

wherein r'_R1、r′_R2Are respectively a swing angle₁，₂At a certain value, the swing center O goes to the lower fulcrum B₁、B₂The specific value of the lower fulcrum vector of (2). r is_E1From the swing center O to an upper fulcrum A₁Of the upper supporting point vector of r_E2From the swing center O to an upper fulcrum A₂The coordinate vector of the upper support point vector of (1).

Technical Field

The present application relates to the field of rockets, and in particular, to a method of determining a change in length of a servo actuator.

Background

Thrust vector control is a commonly used actuating mechanism control method, can directly change the injection direction of a working medium of a reaction thrust device (such as a rocket engine, a jet aircraft engine and the like) through a servo actuator, generates a control force vertical to the motion direction of a carrier (such as a carrier rocket, a missile, a jet aircraft and the like), and has the advantages of strong control capability, quick response and high efficiency.

Taking a thrust vector control mode of a swinging nozzle of a typical rocket engine as an example, as shown in fig. 1, the length direction axes of two channel linear servo actuators are orthogonal, two ends of each channel linear servo actuator are respectively connected to an arrow body and the nozzle through hinges, the nozzle is connected with the engine through a universal joint or a flexible joint with high torsional rigidity or a ball-and-socket hinge, and the connecting point forms a swinging center. If a flexible joint is adopted, the sinking movement of the swing center of the spray pipe can be caused due to the increase of the internal pressure intensity when the engine works. The servo controller controls the length change of the two servo actuators, and further controls the three-dimensional direction of the outlet of the spray pipe, so that the spray pipe presents an ideal outlet direction relative to the carrier, and the control of the thrust vector is realized.

The traditional thrust vector control mode usually adopts independent linear control among channels and is not suitable for a suspension geometric form with obvious inter-channel traction coupling motion; in the suspension geometric form with obvious inter-channel coupling motion in the prior art, the given inverse kinematics solution method is an implicit iteration method of a simultaneous constraint equation set, has the problems of high convergence stability, large calculation amount and the like, is only applied to a ground test system, and is not suitable for on-line servo control with strict requirements on calculation reliability and time.

Therefore, how to determine the length change of the servo actuator aiming at the inverse kinematics problem of thrust vector control is a problem which needs to be solved urgently by the person skilled in the art.

Disclosure of Invention

The invention aims to provide a method for determining length change of a servo actuator, which can determine the length change of the servo actuator aiming at the inverse kinematics problem of thrust vector control.

To achieve the above object, the present application provides a method for determining a change in length of a servo actuator, comprising the steps of: establishing a coordinate system parallel to the arrow structure coordinate system at the swing center;

determining each pivot vector between the swing center and the servo actuator in a coordinate system; determining coordinate vectors of the pivot vectors in a coordinate system; and determining the length change of the two servo actuators according to the coordinate vector of each pivot point vector.

As above, the coordinate vector of an arbitrary vector in the coordinate system is denoted as r, where r is [ r ═ r_xr_yr_z]^TWherein r is_xRepresenting coordinates in the X-axis of the coordinate system, r_yRepresenting coordinates on the Y-axis of the coordinate system, r_zDenotes the coordinates on the Z-axis of the coordinate system and T denotes the transpose of the matrix.

As above, wherein the servo actuators include a pitch servo actuator and a yaw servo actuator.

As above, the upper pivot point where the pitch servo actuator is articulated to the arrow structure is defined as A₁And a lower fulcrum hinged to the nozzle is defined as B₁(ii) a An upper supporting point of the yaw servo actuator hinged with the arrow body structure is defined as A₂And a lower fulcrum hinged to the nozzle is defined as B₂(ii) a Each pivot vector includes: from the centre of oscillation to an upper fulcrum A₁、A₂From the upper supporting point vector, the swing center to the lower supporting point B₁、B₂A lower fulcrum vector of (2); wherein the upper pivot point vector r_E1Upper support point vector r_E2Lower fulcrum vector r_R1And a lower fulcrum vector r_R2The coordinate vectors in the coordinate system are specifically represented as:

wherein x is_pThe amount of sinking of the swing center during operation of the engine can be expressed as a function of the operating pressure P, where x_p(p); h is x_pWhen the swing center reaches the upper supporting point A when the swing center is 0₁Or upper fulcrum A₂Positive X-axis direction distance; e is from the swing center to the upper supporting point A₁From the negative Y-axis direction of (a), or the center of oscillation O to the upper fulcrum A₂Negative Z-axis distance; r is from the swing center O to the lower fulcrum B₁To the lower fulcrum B, or the center of oscillation O₂L is the swing center O to the lower fulcrum B₁Or lower fulcrum B₂The positive X-axis direction distance of (a) is a constant related to the nozzle suspension geometry.

As above, wherein determining the two servo actuator length changes based on the coordinate vectors of the pivot point vectors comprises the sub-steps of: determining a synthetic swing angle; determining a coordinate vector of a unit vector of the central shaft of the spray pipe in a coordinate system according to the synthetic pivot angle; determining a unit vector value along the direction of the synthetic rotating shaft according to the coordinate vector of the unit vector of the central shaft of the spray pipe in the coordinate system; and determining the length command length change of the two servo actuators according to the unit vector value on the synthetic rotating shaft.

As above, where the composite pivot angle Φ is specifically represented as:wherein₁，₂Is the pivot angle of the two channels of the servo actuator.

As above, the unit vectors of the nozzle central shaft include the unit vectors before the nozzle central shaft swings and after the nozzle central shaft swings, and the coordinate vectors of the unit vectors u and u' of the nozzle central shaft after the nozzle central shaft swings and before the swing in the coordinate system are respectively expressed as:

wherein phi is a synthetic swing angle,₁，₂is the swing angle of the two channels.

As above, wherein unit vector values on the rotation axis are synthesizedThe concrete expression is as follows:and u' are unit vectors of the central shaft of the spray pipe located at the zero position before swinging and after swinging respectively.

As above, wherein before determining the change in length of the two servo actuators, further comprising, calculating the pivot angle₁，₂At a certain value, the swing center O goes to the lower fulcrum B₁、B₂The specific value of the lower fulcrum vector of (2); wherein the centre of oscillation O goes to the lower fulcrum B₁、B₂The specific values of the lower fulcrum vector of (2) are expressed as:wherein r is_R1Is a swing angle₁，₂Zero-time swing center O to lower fulcrum B₁Lower support point vector of r_R2Is a swing angle₁，₂Zero-time swing center O to lower fulcrum B₂The lower-fulcrum vector of (a) is,is a unit vector value along the direction of the synthetic rotating shaft, and phi is a synthetic swing angle.

As above, where the two servo actuators vary in length x_r1、x_r2The concrete expression is as follows:wherein r'_R1、r′_R2Are respectively a swing angle₁，₂At a certain value, the swing center O goes to the lower fulcrum B₁、B₂The specific value of the lower fulcrum vector of (2). r is_E1From the swing center O to an upper fulcrum A₁Of the upper supporting point vector of r_E2From the swing center O to an upper fulcrum A₂The coordinate vector of the upper support point vector of (1).

The beneficial effect of this application is: according to the method and the device, the required accurate length change of the two servo actuators can be given out completely through forward calculation of limited steps according to the two-channel deflection angle instruction of the real-time requirement of the thrust vector and the preset suspension geometric size constant (the sinking amount of the thrust device after pressurization can be considered).

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art according to the drawings.

FIG. 1 is a schematic view of a prior art swing spout;

FIG. 2A is a schematic diagram of a planar structural constraint relationship of a pitch channel actuator according to an embodiment of the present application;

FIG. 2B is a schematic view of a planar structural constraint relationship of a yaw channel actuator according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a two channel actuator simultaneously driving a weaving nozzle (only pitch channel actuator is shown) provided in accordance with an embodiment of the present application;

FIG. 4 is a flow chart of a method for determining a change in length of a servo actuator according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application are clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The present application relates to a method of determining a change in length of a servo actuator. According to the method and the device, the accurate length change of the two required servo actuators can be completely calculated in the forward direction according to the two-channel swing angle instruction of the real-time requirement of the thrust vector and the preset suspension geometric size constant.

As can be seen from fig. 1, one end of each of the pitch channel actuator and the yaw channel actuator is connected to the nozzle tube and is located in two mutually perpendicular planes in the zero position. Referring to fig. 2, fig. 2A is a schematic diagram illustrating a planar structure constraint relationship of a pitch channel actuator, and fig. 2B is a schematic diagram illustrating a planar structure constraint relationship of a yaw channel actuator according to an embodiment of the present application.

Continuing to refer to FIG. 2, the nozzle of FIGS. 2A and 2B is coupled to the engine at a point that forms a swing center O. In fig. 2A, two ends of the pitch channel actuator are respectively hinged with the arrow body and the nozzle, wherein the hinged point with the arrow body is an upper supporting point a₁The hinged point with the spray pipe is a lower fulcrum B₁. In FIG. 2B, the hinge point of the yaw channel actuator and the arrow structure is shown as upper fulcrum A₂The hinged point with the spray pipe is a lower fulcrum B₂。

The flight controller controls the yaw channel actuator or the pitching channel actuator to extend or shorten to drive the spray pipe to deflect angularly, and the three-dimensional direction of the outlet of the spray pipe changes, so that the change of the thrust vector is realized. The yaw channel actuator or the pitch channel actuator corresponds to one channel, namely the yaw channel and the pitch channel, wherein a control instruction sent by the aircraft is a swing angle instruction, and the two channels are indicated to change a swing angle, so that the three-dimensional direction of the outlet of the spray pipe is changed. In this embodiment, the swing angle command issued by the flight controller each time is a value periodically updated according to the flight state, in order to make the nozzle perform swing angle deflection according to the command, and if the swing angle deflection of the nozzle is to be realized, the length change of the servo actuator needs to be obtained.

The present application provides a method for determining a change in length of a servo actuator, as shown in fig. 4, comprising the steps of:

step S410: a coordinate system parallel to the arrow structure coordinate system is established at the swing center.

A coordinate system O-XYZ parallel to the coordinate system of the arrow structure is established with the swing center O as the center of the coordinate system, wherein the pitch channel actuators lie in the XOY plane, as shown in fig. 2A and 3. The yaw channel actuator is located in the XOZ plane, as shown in FIG. 2B. Wherein, any vector coordinate vector in the coordinate system O-XYZ is recorded as r, r ═ r_xr_yr_z]^TWherein r is_xRepresenting the coordinates in the X-axis of the coordinate system O-XYZ, r_yThe coordinates, r, expressed on the Y-axis of the coordinate system O-XYZ_zThe coordinates on the Z-axis of the coordinate system O-XYZ are represented and T represents the transpose of the matrix.

Step S420: pivot point vectors between the center of oscillation and the servo actuator are determined in a coordinate system.

In particular, the fulcrum vector between the swing center O and the servo actuator is from the swing center O to the upper fulcrum A₁、A₂And from the centre of oscillation O to the lower fulcrum B₁、B₂The vector of (2).

Specifically, the swing center O reaches the upper fulcrum a₁Is taken as the upper pivot vector r_E1As shown in fig. 3. Swing angle₁，₂When both are zero (i.e. the nozzle is located at the position shown on the left in fig. 3, the nozzle central shaft is located at the zero position before swinging), the unit vector of the nozzle central shaft is marked as u, and the swinging center O is located at the lower support point B₁Is denoted as the lower support point vector r_R1. Two-channel swing angle₁，₂At a certain value (i.e. the nozzle has been pivoted to the position shown on the right in fig. 3) the unit vector of the nozzle centre axis is denoted u', the centre of pivoting O is denoted the lower fulcrum B₁Is denoted as the lower support point vector r'_R1。

Further, the swing center O reaches the upper fulcrum a₂Is denoted as the upper point vector r_E2. Swing angle of two channels of servo actuator₁，₂When the zero point is zero, the swing center O goes to the lower fulcrum B₂Is denoted as the lower support point vector r_R2(ii) a Two-channel swing angle₁，₂At a certain value, the swing center O goes to the lower fulcrum B₂Is denoted as the lower support point vector r'_R2。

Step S430: and determining a coordinate vector of each pivot point vector in a coordinate system.

Specifically, a pivot point vector r_E1、r_E2、r_R1、r_R2The coordinate vectors in the coordinate system O-XYZ are specifically represented as:

wherein x is_pThe amount of sinking of the swing center O during engine operation can be expressed as a function of the operating pressure P (measured from a sensor), where x_pF (p). As can be seen from FIGS. 2A and 2B, where H is cold (x)_p0) to the upper fulcrum a from the center of oscillation O₁Or upper fulcrum A₂A positive X-axis direction distance of (E) from the swing center O to the upper supporting point A₁Or the swing center O to the upper supporting point a₂R is the distance from the swing center O to the lower support point B₁To the lower fulcrum B, or the center of oscillation O₂L is from the center of oscillation O to the lower fulcrum B₁Or lower fulcrum B₂The positive X-axis direction distance of (a) is a constant related to the nozzle suspension geometry.

Step S440: and determining the length change of the two servo actuators according to the coordinate vector of each pivot point vector.

Specifically, the determination of the change in length of the servo actuator is made based on the coordinate vector of each pivot point vector, the pivot angle command, and the unit vector of the nozzle center axis. The method specifically comprises the following substeps:

step D1: and determining a synthetic swing angle.

Further, the swing angles of the two servo actuators are combined and defined as a combined swing angle, wherein the combined swing angle Φ is specifically expressed as:

wherein₁，₂Is the pivot angle of the two channels of the servo actuator.

Step D2: and determining a coordinate vector of a unit vector of the central shaft of the spray pipe in the coordinate system according to the synthetic pivot angle.

Specifically, coordinate vectors of unit vectors u and u' of the central shaft of the nozzle after swinging, which are located at the zero position before swinging, in a coordinate system are respectively expressed as follows:

wherein phi is a synthetic swing angle,₁，₂is the swing angle of the two channels.

Step D3: and determining a unit vector value along the direction of the synthetic rotating shaft according to the coordinate vector of the unit vector of the central shaft of the spray pipe in the coordinate system.

The unit vector of the central shaft of the spray pipe comprises the unit vector which is positioned at a zero position before swinging and the unit vector after swinging, so that the synthetic rotating shaft is used for expressing the mathematical quantity of the equivalent rotating direction. In particular, the unit vector values on the composite spindle in FIG. 3The concrete expression is as follows:

and u' are unit vectors of the central shaft of the nozzle after swinging and positioned at a zero position before swinging.

Step D4: and determining the length change of the two servo actuators according to the unit vector value on the synthetic rotating shaft.

Wherein before determining the length change of the two servo actuators, the method further comprises calculating a swing angle₁，₂At a certain value, the swing center O goes to the lower fulcrum B₁、B₂The specific value of the lower fulcrum vector of (2).

Specifically, the center of oscillation O to the lower fulcrum B₁、B₂The specific values of the lower fulcrum vector of (2) are expressed as:

wherein r is_R1Is a swing angle₁，₂Zero moving center O to lower fulcrum B₁Lower support point vector of r_R2Is a swing angle₁，₂Zero-time swing center O to lower fulcrum B₂The lower-fulcrum vector of (a) is,the unit vector value on the synthetic rotating shaft is shown, and phi is the synthetic swing angle.

Further, from the swing center O to the lower fulcrum B₂Determining the length change of the two servo actuators according to the lower fulcrum vector value, wherein the length change x of the two servo actuators_r1、x_r2The concrete expression is as follows:

x_r1＝|r′_R1-r_E1|

x_r2＝|r′_R2-r_E2|

wherein r'_R1、r′_R2Are respectively a swing angle₁，₂At a certain value, the swing center O goes to the lower fulcrum B₁、B₂The specific value of the lower fulcrum vector of (2). r is_E1From the swing center O to an upper fulcrum A₁Of the upper supporting point vector of r_E2From the swing center O to an upper fulcrum A₂The coordinate vector of the upper support point vector of (1).

The beneficial effect of this application is: according to the method and the device, the required accurate length change of the two servo actuators can be given out completely through forward calculation of limited steps according to the two-channel deflection angle instruction of the real-time requirement of the thrust vector and the preset suspension geometric size constant (the sinking amount of the thrust device after pressurization can be considered).

Although the present application has been described with reference to examples, which are intended for purposes of illustration only and are not intended to be limiting of the present application, changes, additions and/or deletions may be made to the embodiments without departing from the scope of the application.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.