A method for optimizing the layout of a sensing structure taking into account the overall angular deflection of the test device

Abstract

The application discloses a kind of sensing structure layout optimization method considering overall angular deflection of test device, belongs to aircraft engine vector thrust measurement technical field.For the test performance of sensing structure different quantity and arrangement position in engine vector thrust measurement device, first, the relationship model between input vector force and the stress of each position sensing structure is established, combined with the stiffness anisotropy characteristics of sensing structure, the deformation amount of sensing structure in three directions is obtained.Further combined with the spatial position parameters of sensing structure, the overall deformation and deformation direction of test device are obtained.Change the number of sensing structure and arrangement position, analyze the vector force transmission relationship again, by comparing the overall deflection angle of test device in different layout, the sensing structure layout form with minimum deflection angle is obtained.The application comprehensively considers the state change of engine in test process, solves the problems that error factors are not fully considered and optimization process is complex in other methods, improves test stability and increases test precision.

Description

Technical Field

[0001] This invention belongs to the field of aircraft engine vector thrust measurement technology, and relates to a method for optimizing the layout of sensor structures for the overall angle deflection of a test device. It can realize the calculation of the overall angle deflection of the test device under different numbers and layouts of multiple sensor structures in the thrust test device, optimize the layout, and improve the thrust test accuracy. Background Technology

[0002] With the advancement of science and technology and the rapid development of aviation technology, higher requirements have been placed on the next generation of aircraft. Therefore, engines capable of generating large-value vector thrust are needed to help aircraft achieve operational capabilities. The measurement of engine vector force generally adopts the method of arranging single-component sensors on multiple surfaces (>3) of the engine to restrict the engine's six degrees of freedom and realize the measurement of vector force.

[0003] However, because the direction and magnitude of the vector force on the sensing structures at each measuring point differ, the force values ​​experienced by the sensing structures at different locations in the system will vary. This will also lead to deviations in the three-dimensional deformation, causing a misalignment between the engine's theoretical axis and the reference axis, resulting in errors in force measurement. The layout and number of sensing structures have a significant impact on the overall angular deflection and stability of the testing device. Therefore, optimizing the number and arrangement of sensing structures is crucial.

[0004] Current layout optimization methods only consider the point of force application and the solution of force values. These methods typically assume rigidity and no structural deformation, optimizing the arrangement by comparing the difficulty of solving force parameters under different layouts. However, during vector force application, engine axis misalignment alters force distribution, causing the force measurement direction to deviate from the ideal measurement direction, resulting in intersections between force outputs in different directions. This phenomenon cannot be ignored in the solution of force parameters. Therefore, a sensor structure layout optimization method that can consider the overall angular deflection of the testing device is urgently needed. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a method for optimizing the layout of sensor structures while considering the overall angular deflection of the testing device. First, a relationship model is established between the vector thrust input and the forces acting on each point of the sensor structure. The theoretical output values ​​of the sensor structure are obtained, and its triaxial deformation is calculated based on the stiffness laws of the sensor structure. Combined with the coordinates of the sensor structure's location, the overall angular deflection law of the testing device is calculated. By comparing the degree of engine shaft skew under different arrangement methods and numbers of sensor structures, the layout optimization of the sensor structure is achieved with the goal of minimizing the shaft deflection angle.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for optimizing the layout of sensor structures considering the overall angular deflection of a testing device is disclosed. This optimization method is implemented based on a testing device comprising an engine, a moving frame, sensor structures, and a stationary frame. First, the input vector force is decomposed into three directional components, establishing a force distribution model for each sensor structure under unidirectional force. Then, by utilizing the anisotropic stiffness of the sensor structures, the deformation in the three directions is calculated. Combining the position coordinates of each sensor structure, the relationship between sensor structure deformation and the overall engine axis deflection is established. This allows for the acquisition of the magnitude of engine axis deflection under a given number of sensor structures and their arrangement. By comparing the overall angular deflection of the testing device under different numbers and arrangements, the sensor structure layout with the minimum overall angular deflection of the testing device is obtained.

[0008] The specific steps are as follows:

[0009] Step 1: Establish the force distribution relationship of the testing device under vector force.

[0010] The testing device mainly comprises four parts: an engine, a moving frame, sensing structures, and a fixed frame. The fixed frame is stationary. The engine, the test object, is fixedly connected to the moving frame, and no displacement occurs between them. The moving frame supports the engine, fixed to the engine on its inner side and connected to the sensing structures on its outer side. The sensing structures are arranged between the moving and fixed frames according to a certain pattern. Each sensing structure contains a unidirectional force sensor to measure the external force acting on the engine. A vector force application device is placed at one end of the testing device to generate a standard resultant force, which can be decomposed into three directional components. The engine's axial direction is defined as the X direction, the vertical direction as the Z direction, and the horizontal direction as the Y direction. Three sensing structures ①, ②, and ③ are arranged in the Z direction, two sensing structures ④ and ⑤ are placed in the X direction, and one sensing structure ⑥ is placed in the Y direction. To obtain the force characteristics of each sensing structure at each measuring point under the action of vector force, the force distribution relationship of each sensing structure under the action of unidirectional force needs to be calculated. The sensor structures at each location are decomposed and combined according to their stiffness in each direction. Specifically, the engine and moving frame are simplified into an equivalent rigid body model of the engine. Sensor structures ①, ②, ③, and ④ are simplified into three equivalent elastic supports in each direction, each elastic support only sensing axial force. Sensor structures ⑤ and ⑥ are equivalent to three elastic supports at one location. When a force F acts on the engine outlet A, the force F is first decomposed into three forces along the coordinate axes, and the forces felt by each sensor structure in each direction are calculated. That is, it is simplified to three unidirectional support points, each of which only bears normal force and not tangential force. Through the principle of spatial force-torque balance and the law of rigid body rotation, a system of multivariate equations is established to calculate the contact force of the three supports at each unidirectional support point under the action of unidirectional force. According to the stiffness combination law of each measuring point, the force values ​​in the three directions at the free end of each sensor structure before stiffness simplification can be calculated.

[0011] The calculation formula is shown in equation (1).

[0012]

[0013] Where i = 1, 2, ..., n represents the equivalent elastic support at each position; j = x, y, z represents the force direction of the equivalent elastic support; F x F represents the external force in the X direction. xi F represents the elastic support force value in the X direction; y F represents the external force in the Y direction. yi F represents the force applied to the elastic support in the Y direction. z F represents the external force in the Z direction. zi Indicates the value of the elastic support sensing force in the Z direction; M x M y M z F represents the torque about the three coordinate axes. ij K represents the force in the j-direction acting on the elastic support at position i; ij This represents the stiffness value of the elastic support at position i in the j direction.

[0014] Step 2: Calculate the deformation of the sensor structure at each measuring point and the engine axis misalignment.

[0015] The force values ​​calculated for the sensing structure at different locations are denoted as F. ij (i = x, y, z; j = 1, 2, 3, ...), the deformation in three directions at the connection point between the sensing structure and the moving frame is calculated and denoted as u. ij (i is the position number of the sensing structure, i = 1, 2, 3, ...; j is the displacement direction of the sensing structure, j = x, y, z). The moving frame and the engine as a whole will also undergo the same deformation as the sensing structure at this position. When calculating the overall axial deviation of the engine, it is necessary to analyze the relationship between the deformation of the moving frame in each direction and the deformation of the sensing structure, determine the sensing structure number and deformation direction related to the deformation of the moving frame in the X, Y, and Z directions, and then calculate the overall deflection angle of the test device, as shown in formula (1).

[0016]

[0017] Where, α x α y α z represents the rotation angle of the testing device around the X, Y, and Z coordinate axes, respectively; f(), g(), and h() represent the functional relationships between the rotation angles of the X, Y, and Z coordinate axes and the displacement quantities, respectively.

[0018] Step 3: Optimization of multiple layouts of the sensor structure

[0019] Based on the calculated overall deflection angle of the testing device under the vector force, the sensor structure layout is optimized. First, the number of sensor structures is fixed, but the coordinates of their positions and the number of structures in each of the three directions are changed to calculate the engine axis deflection angle. Second, the number of sensor structures is increased or decreased, and the engine axis deflection angle is calculated again using the same steps. The degree of engine axis deflection under each layout is calculated and compared, and the sensor structure layout with the smallest overall deflection angle and the best stability is selected.

[0020] The beneficial effects of this invention are:

[0021] (1) This invention addresses the problem of the overall deflection of the engine test device under the action of vector force in the vector engine thrust measurement device. By establishing a model of the force relationship between the vector force input and the sensing structure at each position, the triaxial force components borne by the free end of the sensing structure are obtained. Combined with the triaxial stiffness law of the sensing structure, the deformation of the sensor structure at each measuring point can be calculated, and then the degree of engine axis deflection can be obtained. By calculating the axis deviation under different number and layout of sensing structures, the optimal layout can be obtained.

[0022] (2) This method analyzes the causes of errors during engine testing, namely, the engine axis is deflected under force. It establishes a relationship model between the sensor structure layout and the axis deflection, comprehensively considers the changes in engine state during the test, solves the problems of incomplete consideration of error factors and complex optimization process in other methods, improves test stability and increases test accuracy. Attached Figure Description

[0023] Figure 1 To optimize the method flowchart.

[0024] Figure 2 This is a schematic diagram of the layout of the vector force testing device and sensing structure.

[0025] Figure 3 This is a schematic diagram of the stiffness equivalent of the measuring device.

[0026] In the diagram: ①, ②, and ③ represent the Z-direction sensing structure of the test system; ④ and ⑤ represent the X-direction sensing structure of the test system; ⑥ represents the Y-direction sensing structure of the test system; 1x, 1y, and 1z represent the equivalent supports in the three directions for position 1; 2x, 2y, and 2z represent the equivalent supports in the three directions for position 2; 3x, 3y, and 3z represent the equivalent supports in the three directions for position 3; 4x, 4y, and 4z represent the equivalent supports in the three directions for position 4; 5x, 5y, and 5z represent the equivalent supports in the three directions for position 5; A represents the simulated engine model; B represents the moving frame structure; OXYZ represents the global coordinate system; C represents the theoretical axis of the engine; D represents the axis after engine deflection; and E represents the equivalent rigid body model of the engine. Detailed Implementation

[0027] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings and technical solutions.

[0028] A method for optimizing the sensor structure layout considering the overall angular deflection of the testing device is disclosed. This optimization method is implemented based on the testing device, which comprises four parts: an engine, a moving frame, sensor structures, and a stationary frame. This embodiment uses a testing system employing six sensor structures as an example.

[0029] Step 1: Establish the force distribution relationship under the action of vector force

[0030] Define the engine's axial direction as the X direction, the vertical direction as the Z direction, and the horizontal direction as the Y direction. Three sensing structures ①, ②, and ③ are arranged in the Z direction to ensure the stability of the test bench suspension. Two sensing structures ④ and ⑤ are placed in the X direction to bear the large axial force, and one sensing structure ⑥ is placed in the Y direction to measure the force in the Y direction. Figure 2 The test structure is simplified to Figure 3 In the model, engine A and moving frame B are simplified into an equivalent rigid body model E of the engine. Sensing structures ①, ②, ③, and ④ are simplified into three equivalent elastic supports in three directions, each elastic support can only sense axial force. Sensing structures ⑤ and ⑥ are equivalent to three elastic supports at one location. When a force F acts on the outlet end of engine A, the force F is first decomposed into three forces along the coordinate axes, and the forces that each sensing structure can sense in the three directions are solved separately when the forces in the three directions are applied.

[0031] When Fx acts alone, it can be calculated according to formula (3).

[0032]

[0033] When Fy acts alone, it can be calculated according to formula (4).

[0034]

[0035] When Fz acts alone, it can be calculated according to formula (5).

[0036]

[0037] Step 2: Calculate the deformation of the sensor structure at each measuring point and the engine axis misalignment.

[0038] After the equivalent support force calculation at each location is completed, the equivalent support is restored, and the force value is distributed according to the combined stiffness ratio. The triaxial force value of each sensing structure in the test structure can then be obtained. Based on the stiffness anisotropy law of the sensing structure, the deformation of the connection end between each sensing structure and the moving frame can be calculated by using the calculated triaxial force value of each sensing structure at each location. Using the position coordinates of the sensing structure as parameters, the overall deflection angle of the test device can be calculated by formula (6).

[0039]

[0040] Step 3: Optimization of various layouts for the sensor structure

[0041] By changing the number and arrangement of the sensing structures, the test layout is analyzed through the same process described above. The optimal layout is selected with the goal of minimizing the overall deflection angle of the test device.

[0042] This method analyzes the force transmission mechanism of the testing device, establishes a force flow transmission model, and obtains the force values ​​in three directions at the connection end between each sensing structure and the moving frame. Based on the anisotropic stiffness of the sensing structure, it obtains the triaxial deformation of the sensing structure at each position, and then calculates the offset and skew angle of the engine axis. By changing the layout of the sensing structure, it calculates the engine axis skew in each case, obtaining the layout with the minimum skew, thus optimizing the test device layout. The influence of different layout methods on the test is analyzed, the causes of test errors are traced, and the problem of incomplete consideration of factors in current layout optimization is solved. The layout is optimized from the root, improving the rotation angle and stability of the testing device and reducing test errors.

[0043] Although the present invention has been described in detail, it is not limited to the situations described above. Those skilled in the art, upon understanding the present invention, can make changes without departing from its scope. This method can also be used for optimized layouts of seven-sensor structures, eight-sensor structures, etc. Therefore, any additions to the technology and substitutions of similar content in the art should fall within the protection scope of this invention.

Claims

1. A method for optimizing the layout of a sensing structure considering the overall angular deflection of the testing device, characterized in that, The sensor structure layout optimization method is implemented based on a testing device, which includes an engine, a moving frame, sensor structures, and a fixed frame. First, the input vector force is decomposed into three directional components, and a force distribution model for each sensor structure under unidirectional force is established. Then, through the stiffness anisotropy of the sensor structures, the deformation in the three directions is calculated. Second, combining the position coordinates of each sensor structure, the relationship between the sensor structure deformation and the overall engine axis deviation is established, thus obtaining the magnitude of the engine axis deviation for that sensor structure and its arrangement. Finally, using this method, the overall angular deflection of the testing device is compared under different quantities and arrangement methods to obtain the sensor structure layout with the smallest overall angular deflection. Includes the following steps: Step 1: Establish the force distribution relationship of the testing device under the action of vector force; The testing device mainly comprises four parts: an engine, a moving frame, a sensing structure, and a fixed frame, wherein the fixed frame is fixed. The engine, being the test object, is fixedly connected to the moving frame, and no displacement occurs between them. The moving frame supports the engine, with its inner side fixed to the engine and its outer side connected to the sensing structure. The sensing structure is arranged between the moving frame and the fixed frame, and each sensing structure contains a unidirectional force sensor to measure the external force acting on the engine. A vector force application device is placed at one end of the testing device to generate a standard resultant force, which can be decomposed into three directional components. The engine's axial direction is defined as the X direction, the vertical direction as the Z direction, and the horizontal direction as the Y direction. Three sensing structures ①, ②, and ③ are arranged in the Z direction, two sensing structures ④ and ⑤ are placed in the X direction, and one sensing structure ⑥ is placed in the Y direction. To obtain the force characteristics of each sensing structure at each measuring point under the action of the vector force, the force distribution relationship of each sensing structure under the action of the unidirectional force needs to be calculated. The sensor structures at each sensor location are divided and combined according to their stiffness in each direction. Specifically, the engine and the moving frame are simplified into an equivalent rigid body model of the engine. Sensor structures ①, ②, ③, and ④ are simplified into three equivalent elastic supports in three directions. Each elastic support can only feel axial force. Sensor structures ⑤ and ⑥ are equivalent to three elastic supports at one location. When a force F acts on the engine A outlet end, the force F is first decomposed into three forces along the coordinate axis direction. When the three forces act, the force in each direction that each sensor structure can feel is calculated. That is, it is simplified into three unidirectional support points. Each unidirectional support point only bears normal force and not tangential force. Through the principle of spatial force-torque balance and the law of rigid body rotation, a multivariate equation system is established to calculate the contact force of the three supports of each unidirectional support point under the action of unidirectional force. According to the stiffness combination law of each measuring point, the force values ​​in three directions of each sensor structure free end before the stiffness of the measuring point is simplified can be calculated. The calculation formula is shown in equation (1). (1) in, This represents the external force acting in the X direction. This indicates the value of the elastic support force in the X direction; This represents the external force in the Y direction. This indicates the force value of the elastic support in the Y direction; This represents the external force in the Z direction. This indicates the value of the elastic support force in the Z direction; , , This represents the torque about the three coordinate axes; Step 2: Calculate the deformation of the sensor structure at each measuring point and the engine axis deviation; Based on the calculated force values ​​experienced by the sensing structure at different locations, denoted as... F ij ,at this time i Number the location of the sensing structure, take i =1,2,3,···n; j Let the direction of displacement of the sensing structure be taken. j = x , y , z The deformation in three directions at the connection point between the sensing structure and the moving frame was calculated and denoted as... u ij ,at this time i Number the location of the sensing structure, take i =1,2,3,···n; j Let the direction of displacement of the sensing structure be taken. j = x , y , z The moving frame and the engine as a whole will also undergo the same deformation as the sensing structure at this position. When calculating the overall axial deviation of the engine, it is necessary to analyze the relationship between the deformation of the moving frame in each direction and the deformation of the sensing structure, determine the sensing structure number and deformation direction related to the deformation of the moving frame in the X, Y, and Z directions, and then calculate the overall deflection angle of the test device, as shown in formula (2). (2) in, , , These represent the rotation angles of the testing device around the X, Y, and Z coordinate axes, respectively. f (), g (), h () represent the functional relationships between the rotation angles of the X, Y, and Z coordinate axes and the displacement quantities, respectively; Step 3: Optimize the layout of multiple sensor structures; Based on the calculated overall deflection angle of the test device under the action of vector force, the layout of the sensing structure is optimized. First, the number of sensing structures is fixed, and the coordinates of the position of the sensing structures and the number of them in the three directions are changed to calculate the deflection angle of the engine axis. Second, the number of sensing structures is increased or decreased, and the engine axis deflection angle is calculated through the same calculation process as the first and second steps. The degree of engine axis deflection under each layout is calculated and compared, and the sensing structure layout with the smallest overall deflection angle and the best stability is selected.

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