Test model quality attribute matching design method considering component movement

Abstract

The invention provides a test model quality attribute matching design method considering component motion, which comprises the following steps of: establishing a test model in component linear motion, a mass center relation model of a fixed component and a moving component and a rotational inertia relation model; calculating the mass, the mass center real-time position and the rotational inertia relative to the mass center of the moving part based on the model; designing an entity test model based on the obtained quality attributes, and obtaining the actual value and the theoretical value of the combined mass center position and the actual value and the theoretical value of the total rotational inertia of the moving part at the starting position, the ending position and the typical middle position based on the entity test model and the theoretical design model; the mass attribute of the balancing weight is designed by analyzing the difference between the actual value and the theoretical value, and real-time simulation of the physical test model on the dynamic change of the mass attribute of the theoretical design model in the component movement process is achieved. By applying the technical scheme, the technical problem that in the prior art, it is difficult for a test model to accurately simulate dynamic changes of quality attributes of a theoretical design model is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of test model mass attribute matching design, and in particular to a test model mass attribute matching design method taking component movement into consideration. Background Art

[0002] With the continuous advancement of aerospace technology, the new generation of aircraft usually focuses on more flexible and changeable flight styles, which puts forward an urgent need for the research of aircraft deformation technology. When the aircraft is dynamically deformed, its own attitude angle, angular velocity and linear velocity of the components will change continuously over time, showing the nonlinear coupling phenomenon of multiple disciplines such as aerodynamics, motion and structure, which brings challenges to the wind tunnel test research of such problems. At present, some wind tunnel test research has been carried out on deformable aircraft at home and abroad, but the research content mainly focuses on the design of test schemes, test measurement accuracy, test data processing and other aspects. There is little discussion on the technical difficulties in the test model design link, especially in considering the changes in mass properties caused by the linear motion of components.

[0003] Limited by the cross-sectional size of the wind tunnel test section, the test model usually needs to be designed with a certain scale, which leads to a significant compression of its own structural space. In terms of test model design, compared with the non-deformable test model, the design difficulty and complexity of the test model considering the linear motion of the components will be significantly increased. In addition to satisfying the basic similarity theory of wind tunnel tests, it is also necessary to focus on the dynamic process of the linear motion of the components. The linear motion of the components will cause direct changes in physical quantities such as the center of mass and moment of inertia of the test model, indirectly affecting the change of the attitude angle of the test model in the wind tunnel, and then changing its unsteady aerodynamic characteristics. Therefore, in order to truly reflect the kinematic and dynamic responses of the actual aircraft during the dynamic deformation process, it is particularly important to simulate the dynamic changes of the mass attributes of the test model. However, considering the complexity of the deformation process, the research on such problems usually needs to be combined with the specific deformation process of the components and carry out targeted analysis. Based on this, this paper conducts relevant research on the dynamic changes of the mass attributes of the test model under the linear motion of the components, and proposes a design and analysis method for matching the mass attributes of the test model under the linear motion of the components. Summary of the invention

[0004] The present invention provides a test model mass attribute matching design method taking component movement into consideration, which can solve the technical problem in the prior art that the test model is difficult to accurately simulate the dynamic changes in the mass attributes of the theoretical design model.

[0005] According to one aspect of the present invention, a method for designing mass attribute matching of a test model considering component motion is provided. The test model includes a fixed component as a main structure of the test model and a moving component arranged on the fixed component. The moving component performs translational motion along an interface with the fixed component. The method includes:

[0006] Based on the kinematic relationship of rigid bodies and the parallel axis theorem, a theoretical design model, a first center of mass relationship model and a first moment of inertia relationship model of fixed parts and moving parts are established;

[0007] Obtain the total mass (m'+m) of the theoretical design model and the real-time position of the combined center of mass (x G (t),y G (t),z G (t)), real-time value of total moment of inertia of theoretical design model (J xG (t),J yG (t),J zG (t)), the mass of the fixed part m′, the position of the center of mass of the fixed part (x′, y′, z′), and the moment of inertia of the fixed part relative to its own center of mass (J x ′,J y ′,J z ′), and the mass m of the moving part is calculated based on the total mass (m'+m) of the theoretical design model and the mass m' of the fixed part;

[0008] Based on the first centroid relationship model, the real-time position of the centroid of the theoretical design model (x G (t),y G (t),z G (t)), the total mass (m'+m) of the theoretical design model, the mass of the fixed component m', the position of the center of mass of the fixed component (x', y', z') and the mass of the moving component m are used to calculate the real-time position of the center of mass of the moving component (x(t), y(t), z(t));

[0009] Based on the first moment of inertia relationship model, according to the total mass (m'+m) of the theoretical design model, the total moment of inertia real-time value (J xG (t),J yG (t),J zG (t)), the mass of the fixed part m′, the position of the center of mass of the fixed part (x′, y′, z′), the moment of inertia of the fixed part relative to its own center of mass (J x ′,J y ′,J z ′), the mass m of the moving part and the real-time position of the center of mass of the moving part (x(t), y(t), z(t)) to calculate the moment of inertia (J) of the moving part relative to its own center of mass x (0),J y (0),J z (0));

[0010] Based on the calculated real-time position of the center of mass of the moving part (x(t), y(t), z(t)) and the moment of inertia of the moving part relative to its own center of mass (J x (0),J y (0),J z (0)) designing a physical moving part, installing the designed physical moving part on the designed physical fixed part to obtain a physical test model;

[0011] Establish the second center of mass relationship model and the second moment of inertia relationship model among the counterweight block, theoretical design model and physical test model;

[0012] The actual value of the combined center of mass position and the actual value of the total moment of inertia of the moving parts in the physical test model are measured respectively when they are at the starting position, the end position and the middle position of the movement, and the real-time position of the combined center of mass of the theoretical design model (x G (t),y G (t),z G (t)) and the real-time value of the total moment of inertia of the theoretical design model (J xG (t),J yG (t),J zG (t)) respectively calculate the theoretical value of the combined center of mass position and the theoretical value of the total moment of inertia when the moving part is at the starting position, the ending position and the middle position of the movement;

[0013] The center of mass position (x) of the counterweight block is determined based on the difference between the actual value of the combined center of mass position corresponding to the starting position of the movement and the theoretical value of the combined center of mass position, the difference between the actual value of the combined center of mass position corresponding to the end position of the movement and the theoretical value of the combined center of mass position, the difference between the actual value of the combined center of mass position corresponding to the middle position of the movement and the theoretical value of the combined center of mass position, and the structural space of the physical test model. p ,y p ,z p );

[0014] Based on the second center of mass relationship model and the determined center of mass position of the counterweight block (x p ,y p ,z p ) Calculate the mass of the counterweight m p ;

[0015] Based on the second moment of inertia relationship model and the mass m of the counterweight p Calculate the moment of inertia (J) of the counterweight relative to its own center of mass xp ,J yp ,J zp ).

[0016] Furthermore, the first center of mass relationship model among the theoretical design model, the fixed components and the moving components is:

[0017] x G (t)=[m'x'+m·x(t)] / (m'+m),

[0018] y G (t)=[m'y'+m·y(t)] / (m'+m),

[0019] z G (t)=[m'z'+m·z(t)] / (m'+m),

[0020] Furthermore, the first moment of inertia relationship model among the theoretical design model, the fixed component and the moving component is:

[0021] J xG (t) = J x (0)+J' x +[m'm / (m'+m)]·d 2 ,

[0022] J yG (t) = J y (0)+J' y +[m'm / (m'+m)]·d 2 ,

[0023] J zG (t) = J z (0)+J' z +[m'm / (m'+m)]·d 2 ,

[0024] d 2 =[x(t)-x'] 2 +[y(t)-y'] 2 +[z(t)-z'] 2 ,

[0025] In the above formula, d 2 It represents the square of the distance from the center of mass of the moving part to the center of mass of the fixed part.

[0026] Furthermore, the second center of mass relationship model among the counterweight, the theoretical design model and the physical test model is:

[0027] m p =(m'+m)[x" G (t)-x G (t)] / [x G (t)-x p ],

[0028] m p =(m'+m)[y" G (t)-y G(t)] / [y G (t)-y p ],

[0029] m p =(m'+m)[z" G (t)-z G (t)] / [z G (t)-z p ],

[0030] Furthermore, the second moment of inertia relationship model among the counterweight, the theoretical design model and the physical test model is:

[0031] J xG (t) = J” xG (t)+(m'+m){[x G (t)-x” G (t)] 2 +[y G (t)-y” G (t)] 2 +[z G (t)-

[0032] z” G (t)] 2}+J xp +m p {[x G (t)-x p ] 2 +[y G (t)-y p ] 2 +[z G (t)-z p ] 2},

[0033] J yG (t) = J” yG (t)+(m'+m){[x G (t)-x” G (t)] 2 +[y G (t)-y” G (t)] 2 +[z G (t)-

[0034] z” G (t)] 2}+J yp +m p {[x G (t)-x p ] 2 +[y G(t)-y p ] 2 +[z G (t)-z p ] 2},

[0035] J zG (t) = J” zG (t)+(m'+m){[x G (t)-x” G (t)] 2 +[y G (t)-y” G (t)] 2 +[z G (t)-

[0036] z” G (t)] 2}+J zp +m p {[x G (t)-x p ] 2 +[y G (t)-y p ] 2 +[z G (t)-z p ] 2},

[0037] In the above formula, (J x ″ G (t),J y ″ G (t),J z ″ G (t)) represents the real-time value of the total moment of inertia of the physical test model, (x′ G ′(t),y′ G ′(t),z′ G ′(t)) represents the real-time position of the center of mass of the physical test model.

[0038] By applying the technical solution of the present invention, a method for designing the mass attribute matching of a test model taking into account the movement of a component is provided. The method is based on the kinematic relationship of a rigid body and the parallel axis theorem, and a center of mass relationship model and a moment of inertia relationship model among the test model, the fixed component and the moving component in the linear motion of the component are established. The real-time position of the center of mass of the moving component and the moment of inertia of the moving component relative to its own center of mass are calculated based on the model. A physical test model is designed based on the mass attribute of the moving component obtained above, and the actual value of the combined center of mass position and the moment of inertia of the moving component when the moving component is at the starting position, the ending position and the typical intermediate position are measured based on the physical test model. The actual value of the total moment of inertia; then, a center of mass relationship model and a moment of inertia relationship model among the counterweight block, the theoretical design model and the physical test model are established, and based on the model, the theoretical value of the combined center of mass position and the theoretical value of the total moment of inertia when the moving part is at the starting position, the ending position and the typical intermediate position are obtained; by analyzing the difference in the combined center of mass and the moment of inertia of the test model under the theoretical state and the actual state, the mass properties of the counterweight block that needs to be added or deleted are designed, and the real-time simulation of the dynamic changes of the mass properties of the theoretical design model by the physical test model during the movement of the part is realized, which can be used to guide the design of the test model of the deformable aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 A schematic diagram showing the principle of the change of the center of mass of the linear motion of the test model component provided in accordance with a specific embodiment of the present invention is shown;

[0041] Figure 2 A schematic diagram showing the principle of changing the mass properties by adding a counterweight to a test model provided in a specific embodiment of the present invention is shown. DETAILED DESCRIPTION

[0042] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0044] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0045] The purpose of the present invention is to propose a design and analysis method for mass attribute matching of a wind tunnel test model during the linear motion of components. This method closely revolves around the development needs of the deformation capability of a new generation of aircraft, focuses on the difficulties in the design of test models in the dynamic deformation process, focuses on the changes in mass attributes such as the center of mass and moment of inertia of the model caused by the deformation of components, and provides relevant solutions. It should be noted that the deformation processes described in the present invention are all deformations of rigid body components, and the deformation technology involved is mainly structural motion deformation, which is a simple linear displacement process. For ease of discussion, the present invention uses a simplified test model consisting of a moving component and a fixed component to carry out method research, wherein the moving component is located above the fixed component and can perform translational motion along the interface between the two. During the linear motion of the component, the combined center of mass and total moment of inertia of the test model will change in real time. For a specific test model, the fixed component here can be regarded as the main structure of the test model, and the moving component can be regarded as the linear motion structure of the model.

[0046] In the design phase of the test model, it is usually necessary to give priority to the design of the main structure (fixed parts) of the test model under the constraints of size envelope, structural strength, structural weight, etc. After completing the above design, the envelope of the structural space size is basically determined. It is usually difficult to design the moving parts in the above space, which puts forward potential constraints on the mass of the moving parts, the real-time position of the center of mass and the design of their own moment of inertia. In addition, after the designed test model is processed, there is usually a certain deviation between the measured value and the design value of the model's mass attribute. The impact of this deviation is similar to the effect caused by the sliding motion of the component, and it will also affect the kinematic and dynamic characteristics of the model, thereby changing the force characteristics of the test model. In response to this problem, the present invention adopts the method of adding or deleting counterweight blocks to match the mass attributes of the processed test model.

[0047] The present invention will mainly focus on the technical difficulties in the above two aspects, and through dimensional analysis, rigid body plane kinematic relationship, parallel axis theorem and other analytical methods, carry out research and discussion from a theoretical level, and provide a test model mass attribute matching design and analysis method under component linear motion, so as to provide a technical reference for relevant personnel to carry out the test model design of deformable aircraft.

[0048] Specifically, according to a specific embodiment of the present invention, a test model mass attribute matching design method considering component movement is provided, wherein the test model includes a fixed component as a main structure of the test model and a moving component arranged on the fixed component, and the moving component performs translational movement along an interface with the fixed component. The method includes:

[0049] Based on the kinematic relationship of rigid bodies and the parallel axis theorem, a theoretical design model, a first center of mass relationship model and a first moment of inertia relationship model of fixed parts and moving parts are established;

[0050] Obtain the total mass (m'+m) of the theoretical design model and the real-time position of the combined center of mass (x G (t),y G (t),z G (t)), real-time value of total moment of inertia of theoretical design model (J xG (t),J yG (t),J zG (t)), the mass of the fixed part m′, the position of the center of mass of the fixed part (x′, y′, z′), and the moment of inertia of the fixed part relative to its own center of mass (J x ′,J y ′,J z ′), and the mass m of the moving part is calculated based on the total mass (m'+m) of the theoretical design model and the mass m' of the fixed part;

[0051] Based on the first centroid relationship model, the real-time position of the centroid of the theoretical design model (x G (t),y G (t),z G (t)), the total mass (m'+m) of the theoretical design model, the mass of the fixed component m', the position of the center of mass of the fixed component (x', y', z') and the mass of the moving component m are used to calculate the real-time position of the center of mass of the moving component (x(t), y(t), z(t));

[0052] Based on the first moment of inertia relationship model, according to the total mass (m'+m) of the theoretical design model, the total moment of inertia real-time value (J xG (t),J yG (t),J zG (t)), the mass of the fixed part m′, the position of the center of mass of the fixed part (x′, y′, z′), the moment of inertia of the fixed part relative to its own center of mass (J x ′,J y ′,J z ′), the mass m of the moving part and the real-time position of the center of mass of the moving part (x(t), y(t), z(t)) to calculate the moment of inertia (J) of the moving part relative to its own center of mass x (0),J y (0),J z (0));

[0053] Based on the calculated real-time position of the center of mass of the moving part (x(t), y(t), z(t)) and the moment of inertia of the moving part relative to its own center of mass (J x (0),J y (0),J z(0)) designing a physical moving part, installing the designed physical moving part on the designed physical fixed part to obtain a physical test model;

[0054] Establish the second center of mass relationship model and the second moment of inertia relationship model among the counterweight block, theoretical design model and physical test model;

[0055] The actual value of the combined center of mass position and the actual value of the total moment of inertia of the moving parts in the physical test model are measured respectively when they are at the starting position, the end position and the middle position of the movement, and the real-time position of the combined center of mass of the theoretical design model (x G (t),y G (t),z G (t)) and the real-time value of the total moment of inertia of the theoretical design model (J xG (t),J yG (t),J zG (t)) respectively calculate the theoretical value of the combined center of mass position and the theoretical value of the total moment of inertia when the moving part is at the starting position, the ending position and the middle position of the movement;

[0056] The center of mass position (x) of the counterweight block is determined based on the difference between the actual value of the combined center of mass position corresponding to the starting position of the movement and the theoretical value of the combined center of mass position, the difference between the actual value of the combined center of mass position corresponding to the end position of the movement and the theoretical value of the combined center of mass position, the difference between the actual value of the combined center of mass position corresponding to the middle position of the movement and the theoretical value of the combined center of mass position, and the structural space of the physical test model. p ,y p ,z p );

[0057] Based on the second center of mass relationship model and the determined center of mass position of the counterweight block (x p ,y p ,z p ) Calculate the mass of the counterweight m p ;

[0058] Based on the second moment of inertia relationship model and the mass m of the counterweight p Calculate the moment of inertia (J) of the counterweight relative to its own center of mass xp ,J yp ,J zp ).

[0059] By applying this configuration, a test model mass attribute matching design method considering component motion is provided. This method is based on the kinematic relationship of rigid bodies and the parallel axis theorem, and establishes a center of mass relationship model and a moment of inertia relationship model among the test model, fixed components and moving components in the linear motion of the components. Based on this model, the real-time position of the center of mass of the moving component and the moment of inertia of the moving component relative to its own center of mass are calculated. Based on the mass attribute of the moving component obtained above, a physical test model is designed, and based on this physical test model, the actual value of the combined center of mass position and the total center of mass of the moving component when it is at the starting position, the ending position and the typical intermediate position are measured. Actual value of moment of inertia; then establish a center of mass relationship model and moment of inertia relationship model among the counterweight, theoretical design model and physical test model, and based on the model, obtain the theoretical value of the combined center of mass position and the theoretical value of the total moment of inertia when the moving part is at the starting position, the ending position and the typical intermediate position; by analyzing the difference in combined center of mass and moment of inertia between the test model in the theoretical state and the actual state, design the mass attributes of the counterweight that needs to be added or deleted, and realize the real-time simulation of the dynamic changes of the mass attributes of the theoretical design model by the physical test model during the movement of the part, which can be used to guide the design of the test model of the deformable aircraft. Compared with the prior art, the technical solution of the present invention can solve the technical problem that it is difficult for the test model in the prior art to accurately simulate the dynamic changes of the mass attributes of the theoretical design model.

[0060] Based on the above embodiment, the derivation and establishment process of the first center of mass relationship model, the first moment of inertia relationship model, the second center of mass relationship model and the second moment of inertia relationship model in the embodiment of the present invention is as follows:

[0061] Please refer to Figure 1 In the figure, t represents time, x, y, z represent the three coordinates of the center of mass; subscripts 1 and 2 correspond to state 1 and state 2 respectively; subscript G represents the combined center of mass of the test model; u(t) and v(t) correspond to the moving speeds of the combined center of mass of the test model and the center of mass of the moving part respectively. When the moving part of the test model moves from state 1 (t1, x1, y1, z1) to state 2 (t2, x2, y2, z2) at a speed v(t), the combined center of mass of the test model will move from (t1, x1, y1, z1) to state 2 (t2, x2, y2, z2) at a speed u(t). G1 ,y G1 ,z G1 ) changes to (t2,x G2 ,y G2 ,z G2 ). Through mathematical analysis, the kinematic relationship between the displacement of the center of mass of the moving part and the displacement of the center of mass of the test model can be established. Assume that at any time t, the mass of the fixed part of the test model is m', and its own center of mass (x', y', z') (independent of time t); the mass of the moving part is m, and the center of mass (x(t), y(t), z(t)), then:

[0062] Total structure mass:

[0063] M=m'+m (1)

[0064] The centroid of the model:

[0065]

[0066] From t1 to t2, the distance moved by the center of mass of the moving part is:

[0067]

[0068] The moving distance relationship of the test model and the center of mass is:

[0069]

[0070] It can be seen that the moving distance ΔS of the combined center of mass of the test model is the product of the moving distance Δs of the moving part and the proportional coefficient m / (m'+m), which represents the ratio of the mass of the moving part to the total mass of the test model. Similarly, the ratio of the change distance of the three coordinates of the combined center of mass of the test model and the three coordinates of the center of mass of the moving part all satisfies the above proportional coefficient.

[0071] Among them, formula (2) is the first center of mass relationship model constructed based on the theoretical design model, fixed parts and moving parts.

[0072] After obtaining the above-mentioned relationship between the center of mass coordinates and displacement, the present invention focuses on the change of the moment of inertia in the process. Assume that the moment of inertia of the fixed component relative to its own center of mass (x', y', z') is (J' x ,J' y ,J' z ), which remains unchanged during the deformation process of the component. For the moving component, it moves from time t1 to time t2, ignoring the shape change of the moving component itself (regarding it as a rigid body), and the mass distribution of the moving component itself remains unchanged, then the moment of inertia of the moving component relative to its center of mass at different times is equal, that is: J x (t) = J x (0), J y (t) = J y (0), J z (t) = J z (0).

[0073] At any time t, the parallel axis theorem shows that the x-direction moment of inertia generated by the moving parts and the fixed parts around the combined center of mass of the test model is:

[0074] J xG_1 (t) = J x (0)+m{[x G(txt)] 2 +[y G (t)-y(t)] 2 +[z G (t)-z(t)] 2},

[0075] J xG_2 (t) = J' x +m'd1 2 =J' x +m'{[x G (t)-x'] 2 +[y G (t)-y'] 2 +[z G (t)-z'] 2} (5)

[0076] Sum and simplify, and the total moment of inertia in the x direction around the center of mass of the test model at time t is:

[0077] J xG (t) = J xG_1 (t)+J xG_2 (t)

[0078] =J x (0)+J' x +[m'm / (m'+m)]·d 2 (6)

[0079] in,

[0080] d 2 =[x(t)-x'] 2 +[y(t)-y'] 2 +[z(t)-z'] 2 (7)

[0081] Represents the square of the distance from the center of mass of the moving part to the center of mass of the fixed part. The steps for solving the moment of inertia in the y and z directions are the same, and the specific expression is as follows:

[0082] J yG (t) = J y (0)+J' y +[m'm / (m'+m)]·d 2 (8)

[0083] J zG (t) = J z (0)+J' z +[m'm / (m'+m)]·d 2 (9)

[0084] Among them, expressions (4), (6), (8), and (9) describe the conversion relationship between the moving part itself and the entire test model in terms of the mass center movement distance and the moment of inertia during the dynamic deformation process of the test model. Expressions (6), (7), (8), and (9) constitute the first moment of inertia relationship model constructed by the present invention based on the theoretical design model, the fixed part, and the moving part.

[0085] For wind tunnel tests, the size envelope of the test model will be limited by the size of the test section of the selected test wind tunnel, and it is usually necessary to perform a certain scaled design based on the original shape. Based on dimensional analysis theory, it is not difficult to conclude that the test model and the real aircraft need to meet the following proportional relationship in terms of total mass, combined center of mass and total moment of inertia:

[0086] M 风洞 / M 飞行 =K ρb ×K l 3

[0087] x G风洞 / x G飞行 =y G风洞 / y G飞行 =z G风洞 / z G飞行 =K l (10)

[0088] J 风洞 / J 飞行 =K ρ K l 5

[0089] Where K ρb Represents the ratio of the average mass density of the test model to the real aircraft, K l represents the size ratio of the test model to the real aircraft, K ρ represents the ratio of the incoming flow density in the wind tunnel state to that in the flight state. It can be seen that when the wind tunnel is selected, the model scaling ratio K l OK, assuming K ρb When the wind tunnel test model is consistent, the total mass, combined center of mass and total moment of inertia can be uniquely determined by expression (10). 风洞 、(x G风洞 ,y G风洞 ,z G风洞 ), J 风洞 That is, (m'+m), (x G (t),y G (t),z G (t))、(J xG (t),J yG(t),J zG (t)).

[0090] For a given test model, after the basic design of the main structure of the test model is completed, in order to achieve real-time simulation of the moment of inertia and center of mass during movement, it is usually necessary to design the moving parts independently. Without considering other factors, the known physical quantities at this time include: the total mass of the test model (m'+m), the real-time position of the combined center of mass (x G (t),y G (t),z G (t)), real-time value of total moment of inertia (J xG (t),J yG (t),J zG (t)), the mass m' of the fixed part (test model body structure), its own center of mass (x', y', z'), the moment of inertia relative to its own center of mass (J' x ,J' y ,J' z ). At this time, the mass m of the moving part is uniquely determined by the total mass of the model and the mass of the fixed part, so the proportional constant m / (m'+m) is a known term, and the real-time position of the center of mass of the moving part itself (x(t), y(t), z(t)) can be obtained by expression (2). Substituting the obtained results into equations (6), (7), (8), and (9), the moment of inertia of the moving part itself (J x (0),J y (0),J z (0)). At this time, all mass attribute parameters of the moving parts are known quantities, and the independent design of the moving parts can be carried out according to the above parameter values ​​and the structural space of the test model.

[0091] Furthermore, the above derivation process is only applicable to theoretical situations. In fact, there are often various constraints in the design process of the test model, which leads to a certain deviation in the total moment of inertia or the combined center of mass position measured after the model is processed. This deviation may be caused by the processing accuracy, or it may be caused by the difference between some finished devices inside the model and the real aircraft. In response to this problem, the present invention performs a matching design of mass attributes by adding or deleting counterweight blocks during the actual measurement of the model. At this time, the constraints on the mass simulation in expression (10) will be appropriately relaxed.

[0092] In the embodiment of the present invention, a counterweight block is added to illustrate. Figure 2 As shown, m p represents the mass of the counterweight, x p ,y p 、z p Represent the three coordinates of the center of mass of the counterweight, J xp , Jyp , J zp They represent the moment of inertia of the counterweight relative to its own center of mass; G ,y G 、z G Represent the three coordinates of the combined mass center of the theoretical state test model, J xG , J yG , J zG Respectively represent the three-direction rotational inertia of the theoretical state test model around the combined center of mass; x” G ,y” G ,z” G They represent the three coordinates of the center of mass of the actual state test model when no counterweight is added, J” xG , J” yG , J” zG They represent the three-direction moment of inertia of the actual state test model around the combined center of mass when no counterweight is added, that is, the actual measured value of the physical test model. Among them, the mass of the counterweight m p and the center of mass (x p ,y p ,z p ) are related, and there is only one independent variable between them. The present invention combines the structural space inside the model for matching design. Assuming that the layout space of the counterweight is fixed, the center of mass (x p ,y p ,z p ) is a known quantity. According to the proportional relationship of expression (2), it is easy to obtain:

[0093] m p =(m'+m)[x" G (t)-x G (t)] / [x G (t)-x p ]

[0094] m p =(m'+m)[y" G (t)-y G (t)] / [y G (t)-y p ] (11)

[0095] m p =(m'+m)[z" G (t)-z G (t)] / [z G (t)-z p ],

[0096] Convert the actual moment of inertia of the counterweight and the model to the theoretical state, taking the x-direction moment of inertia as an example, that is:

[0097] JxG (t) = J” xG (t)+(m'+m){[x G (t)-x” G (t)] 2 +[y G (t)-y” G (t)] 2 +[z G (t)-

[0098] z” G (t)] 2}+J xp +m p {[x G (t)-x p ] 2 +[y G (t)-y p ] 2 +[z G (t)-z p ] 2}(12)

[0099] The moment of inertia of the counterweight can be obtained from expression (12): xp Similarly, J can be obtained according to the following formula yp , J zp :

[0100] J yG (t) = J” yG (t)+(m'+m){[x G (t)-x” G (t)] 2 +[y G (t)-y” G (t)] 2 +[z G (t)-

[0101] z” G (t)] 2}+J yp +m p {[x G (t)-x p ] 2 +[y G (t)-y p ] 2 +[z G (t)-z p ] 2}(13)

[0102] J zG (t) = J” zG(t)+(m'+m){[x G (t)-x” G (t)] 2 +[y G (t)-y” G (t)] 2 +[z G (t)-

[0103] z” G (t)] 2}+J zp +m p {[x G (t)-x p ] 2 +[y G (t)-y p ] 2 +[z G (t)-z p ] 2}(14)

[0104] In the above formula, (J x ″ G (t),J y ″ G (t),J z ″ G (t)) represents the real-time value of the total moment of inertia of the physical test model, (x′ G ′(t),y′ G ′(t),z′ G ′(t)) represents the real-time position of the center of mass of the physical test model.

[0105] Among them, the three expressions of formula (11) are the second center of mass relationship model constructed based on the counterweight block, the theoretical design model and the physical test model. Formulas (12), (13) and (14) are the second moment of inertia relationship model constructed based on the counterweight block, the theoretical design model and the physical test model. It can be seen from formulas (11) to (14) that the mass and moment of inertia of the counterweight block are also functions of t. This shows that for the test model involving component deformation movement, in order to eliminate the above error, the counterweight block needs to be loaded into the test model in a new form of movement. Obviously, this is not desirable. In the process of adjusting the mass attribute of the test model, the position of the counterweight block is usually fixed. Based on this, in the embodiment of the present invention, the difference of mass attributes is analyzed for the boundary position and the typical middle position before and after the movement, and the optimal center of mass position of the counterweight block is determined by combining the center of mass difference and the structural space, and then the mass of the counterweight block is determined. Then, by analyzing the difference of the moment of inertia at the boundary of the movement, combined with expressions (12), (13) and (14), a reasonable moment of inertia of the counterweight block is designed.

[0106] The scheme of deleting counterweight in the present invention is similar in principle to the scheme of adding counterweight, which will not be described in detail here.

[0107] In general, the test model mass attribute matching design method considering component motion provided by the present invention includes the following two main aspects:

[0108] (1) Based on the kinematic relationship of rigid bodies and the parallel axis theorem, the real-time changes of the center of mass and total moment of inertia of the test model during the movement of the moving parts along the interface line of the fixed parts are analyzed. Combined with the dimensional analysis theory, the constraints that the center of mass and moment of inertia of the moving parts themselves need to satisfy are given.

[0109] (2) Based on the kinematic relationship of rigid bodies and the parallel axis theorem, the problem of deviation between the design value and the measured value of the model mass attribute is analyzed. Based on the difference in center of mass and moment of inertia between the theoretical state and the actual state, the center of mass position and moment of inertia of the counterweight to be added are analyzed.

[0110] In summary, the present invention provides a test model mass attribute matching design method considering component motion. The method is based on the rigid body kinematic relationship and the parallel axis theorem, and establishes a center of mass relationship model and a moment of inertia relationship model among the test model, the fixed component and the moving component in the linear motion of the component. The real-time position of the center of mass of the moving component and the moment of inertia of the moving component relative to its own center of mass are calculated based on the model. A physical test model is designed based on the mass attribute of the moving component obtained above, and the actual value of the combined center of mass position and the total inertia when the moving component is at the starting position, the ending position and the typical intermediate position are measured based on the physical test model. Actual value of kinetic inertia; then establish a center of mass relationship model and moment of inertia relationship model among the counterweight, theoretical design model and physical test model, and based on the model, obtain the theoretical value of the combined center of mass position and the theoretical value of the total moment of inertia when the moving part is at the starting position, the ending position and the typical intermediate position; by analyzing the difference in combined center of mass and moment of inertia between the test model in the theoretical state and the actual state, design the mass attributes of the counterweight that needs to be added or deleted, and realize the real-time simulation of the dynamic changes of the mass attributes of the theoretical design model by the physical test model during the movement of the part, which can be used to guide the design of the test model of the deformable aircraft. Compared with the prior art, the technical solution of the present invention can solve the technical problem that it is difficult for the test model in the prior art to accurately simulate the dynamic changes of the mass attributes of the theoretical design model.

[0111] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0112] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A test model mass attribute matching design method considering component motion, characterized in that: The test model comprises a fixed component as a main structure of the test model and a moving component arranged on the fixed component, wherein the moving component performs translational motion along an interface with the fixed component, and the method comprises: Based on the kinematic relationship of rigid bodies and the parallel axis theorem, a theoretical design model, a first center of mass relationship model and a first moment of inertia relationship model of fixed parts and moving parts are established; Obtain the total mass (m'+m) of the theoretical design model and the real-time position of the combined center of mass (x G (t),y G (t),z G (t)), real-time value of total moment of inertia of theoretical design model (J xG (t),J yG (t),J zG (t)), the mass of the fixed part m′, the position of the center of mass of the fixed part (x′, y′, z′), and the moment of inertia of the fixed part relative to its own center of mass (J x ′,J y ′,J z ′), and the mass m of the moving part is calculated based on the total mass (m'+m) of the theoretical design model and the mass m' of the fixed part; Based on the first centroid relationship model, the real-time position of the centroid of the theoretical design model (x G (t),y G (t),z G (t)), the total mass (m'+m) of the theoretical design model, the mass of the fixed component m', the position of the center of mass of the fixed component (x', y', z') and the mass of the moving component m are used to calculate the real-time position of the center of mass of the moving component (x(t), y(t), z(t)); Based on the first moment of inertia relationship model according to the total mass (m'+m) of the theoretical design model and the real-time value of the total moment of inertia (J xG (t),J yG (t),J zG (t)), the mass of the fixed part m′, the position of the center of mass of the fixed part (x′, y′, z′), the moment of inertia of the fixed part relative to its own center of mass (J x ′,J y ′,J z ′), the mass m of the moving part and the real-time position of the center of mass of the moving part (x(t), y(t), z(t)) to calculate the moment of inertia (J) of the moving part relative to its own center of mass x (0),J y (0),J z (0)); Based on the calculated real-time position of the center of mass of the moving part (x(t), y(t), z(t)) and the moment of inertia of the moving part relative to its own center of mass (J x (0),J y (0),J z (0)) designing a physical moving part, installing the designed physical moving part on the designed physical fixed part to obtain a physical test model; Establish the second center of mass relationship model and the second moment of inertia relationship model among the counterweight block, theoretical design model and physical test model; The actual value of the combined center of mass position and the actual value of the total moment of inertia of the moving parts in the physical test model are measured respectively when the moving parts are located at the starting position, the ending position and the middle position of the movement, and the real-time position (x G (t),y G (t),z G (t)) and the real-time value of the total moment of inertia of the theoretical design model (J xG (t),J yG (t),J zG (t)) respectively calculate the theoretical value of the combined center of mass position and the theoretical value of the total moment of inertia when the moving part is at the starting position, the ending position and the middle position of the movement; The center of mass position (x) of the counterweight block is determined according to the difference between the actual value of the combined center of mass position corresponding to the starting position of the movement and the theoretical value of the combined center of mass position, the difference between the actual value of the combined center of mass position corresponding to the end position of the movement and the theoretical value of the combined center of mass position, the difference between the actual value of the combined center of mass position corresponding to the middle position of the movement and the theoretical value of the combined center of mass position, and the structural space of the physical test model. p ,y p ,z p ); Based on the second mass center relationship model and the determined counterweight mass center position (x p ,y p ,z p ) Calculate the mass of the counterweight m p ; Based on the second moment of inertia relationship model and the mass m of the counterweight p Calculate the moment of inertia (J) of the counterweight relative to its own center of mass xp ,J yp ,J zp ).

2. The method according to claim 1, characterized in that The first center of mass relationship model among the theoretical design model, fixed parts and moving parts is: x G (t)=[m'x'+m·x(t)] / (m'+m), y G (t)=[m'y'+m·y(t)] / (m'+m), z G (t)=[m'z'+m·z(t)] / (m'+m)。 3. The method according to claim 2, characterized in that The first moment of inertia relationship model among the theoretical design model, fixed parts and moving parts is: J xG (t)=J x (0)+J' x +[m'm / (m'+m)]·d 2 , J yG (t)=J y (0)+J' y +[m'm / (m'+m)]·d 2 , J zG (t)=J z (0)+J' z +[m'm / (m'+m)]·d 2 , d 2 =[x(t)-x'] 2 +[y(t)-y'] 2 +[z(t)-z'] 2 , In the above formula, d 2 It represents the square of the distance from the center of mass of the moving part to the center of mass of the fixed part.

4. The method according to claim 3, characterized in that The second center of mass relationship model among the counterweight, theoretical design model and physical test model is: m p =(m'+m)[x” G (t)-x G (t)] / [x G (t)-x p ], m p =(m'+m)[y” G (t)-y G (t)] / [y G (t)-y p ], m p =(m'+m)[z” G (t)-z G (t)] / [z G (t)-z p ]。 5. The method according to claim 4, characterized in that The second moment of inertia relationship model between the counterweight, theoretical design model and physical test model is: J xG (t)=J” xG (t)+(m'+m){[x G (t)-x” G (t)] 2 +[y G (t)-y” G (t)] 2 +[z G (t)- z” G (t)] 2 }+J xp +m p {[x G (t)-x p ] 2 +[y G (t)-y p ] 2 +[z G (t)-z p ] 2 }, J yG (t)=J” yG (t)+(m'+m){[x G (t)-x” G (t)] 2 +[y G (t)-y” G (t)] 2 +[z G (t)- z” G (t)] 2 }+J yp +m p {[x G (t)-x p ] 2 +[y G (t)-y p ] 2 +[z G (t)-z p ] 2 }, J zG (t)=J” zG (t)+(m'+m){[x G (t)-x” G (t)] 2 +[y G (t)-y” G (t)] 2 +[z G (t)- z” G (t)] 2 }+J zp +m p {[x G (t)-x p ] 2 +[y G (t)-y p ] 2 +[z G (t)-z p ] 2 }, In the above formula, (J x ″ G (t),J y ″ G (t),J z ″ G (t)) represents the real-time value of the total moment of inertia of the physical test model, (x′ G ′(t),y′ G ′(t),z′ G ′(t)) represents the real-time position of the center of mass of the physical test model.

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