Five-degree-of-freedom virtual flight test device based on motion compensation

Abstract

According to the five-degree-of-freedom virtual flight test device based on motion compensation, the test model of the device can complete three-axis rotation motion with the help of the three-degree-of-freedom hinge, and the test model and the abdomen supporting rod can move up and down in the axial direction of the three-fork suspension support so as to complete release of the heaving degree of freedom; and the test model and the three-fork suspension bracket can realize transverse undamped movement under the support of the pneumatic suspension bearing, so that the purpose of releasing the transverse movement freedom degree is achieved. The parallel six-degree-of-freedom mechanism base located at the bottom is responsible for motion compensation of transverse moving, heaving, rolling and pitching degrees of freedom, and based on the structure, the device can achieve the coupling motion test capacity of other five degrees of freedom except front-back motion. Implementation of the above functions is of great significance to improvement of the capability of a wind tunnel virtual flight test to restore real dynamic characteristics of an aircraft model.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft wind tunnel virtual flight test, in particular to a five-degree-of-freedom virtual flight test device based on motion compensation. Background Art

[0002] Wind tunnel virtual flight test generally refers to a test method in which one or several degrees of freedom of an aircraft are released and then tested in a wind tunnel. These include typical three-degree-of-freedom virtual flight tests achieved through three-degree-of-freedom rotating hinges and wind tunnel free flight tests with six degrees of freedom released. However, wind tunnel free flight tests are difficult to control and have low flight tolerance, so their application is relatively limited. The virtual flight test method is classified as a wind tunnel dynamic test. Unlike forced dynamic tests, wind tunnel virtual flight tests mainly refer to free dynamic tests of aircraft models. They are often used in research in the fields of aircraft rudder excitation response, flight control rate verification, flight parameter identification, etc. It is a comprehensive test method that integrates multiple disciplines such as aerodynamics, flight mechanics, and flight control.

[0003] In recent years, a four-degree-of-freedom test method has emerged that further releases the heave degree of freedom on the basis of releasing the three rotational degrees of freedom. In addition to the six-degree-of-freedom wind tunnel free flight, which is not very practical, virtual flight that releases four degrees of freedom is currently a relatively advanced test technology. After considering the heave motion factors, the simulation of the longitudinal motion characteristics of the test model is more realistic, and its characteristics such as frequency and damping ratio are very different from those of the model that only releases three rotational degrees of freedom. In general, the more degrees of freedom are released, the higher the level of dynamic characteristics testing of the model. The wind tunnel free flight test that releases six degrees of freedom is undoubtedly the most capable test method to fully restore the dynamic characteristics of flight, but this method has high requirements on the size of the wind tunnel, flight control means, flight safety protection, and model design, and the test fault tolerance rate is low, so it has not been widely adopted.

[0004] In summary, in the field of virtual flight testing, although the test method of releasing some degrees of freedom is still the main test method, releasing more degrees of freedom to improve test accuracy and simulation fidelity is an important development trend. Therefore, there is an urgent need for a virtual flight test device that can effectively increase the degrees of freedom and improve the test effect, so as to meet the growing test needs of aircraft research and development and promote the further development of aerospace technology. Summary of the invention

[0005] The purpose of the present invention is to provide a five-degree-of-freedom virtual flight test device based on motion compensation to solve the defect that the conventional virtual flight test has a small range of degrees of freedom.

[0006] The invention provides a five-degree-of-freedom virtual flight test device based on motion compensation, comprising a parallel six-degree-of-freedom mechanism base, a three-pronged suspension bracket, a test model and a measurement and control computer, wherein a drive controller is arranged on the parallel six-degree-of-freedom mechanism base; a pneumatic suspension bearing is arranged on the top end of the parallel six-degree-of-freedom mechanism base, and the three-pronged suspension bracket can be slidably inserted on the pneumatic suspension bearing; a belly support strut is installed through the three-pronged suspension bracket in the longitudinal direction, the test model is installed on the top end of the belly support strut through a three-degree-of-freedom hinge, an angle sensor is fixedly installed on the test model, a lateral displacement sensor is fixedly installed on the top end of the parallel six-degree-of-freedom mechanism base, a heave displacement sensor is installed on the bottom end of the belly support strut, and the angle sensor, the lateral displacement sensor, the heave displacement sensor and the drive controller are all connected with the measurement and control computer signal.

[0007] Furthermore, two bearing brackets are fixedly mounted on the base of the parallel six-degree-of-freedom mechanism, and the pneumatic suspension bearings are fixedly mounted on the bearing brackets. The axes of the pneumatic suspension bearings are parallel to each other, and two pneumatic suspension bearings are fixedly mounted on one of the bearing brackets along the axial direction thereof at intervals.

[0008] Furthermore, the three-pronged suspension bracket includes a main support tube, and three parallel sliding rods are arranged on the side of the main support tube, one of the sliding rods is located on the side opposite to the other two sliding rods, and each of the sliding rods can be slidably inserted on the corresponding pneumatic suspension bearing.

[0009] Furthermore, linear bearings are installed at two ports of the main support tube, and the abdominal support rod is sleeved inside the linear bearings.

[0010] Furthermore, the sum of the length of the sliding rod and the outer diameter of the main support tube is greater than the distance between the two bearing supports.

[0011] Furthermore, the axes of the two sliding rods located at the bottom ends coincide with each other.

[0012] Furthermore, the installation height of the lateral displacement sensor coincides with the height position of the sliding rod located at the bottom end.

[0013] Furthermore, the three-pronged suspension bracket is made of carbon fiber material.

[0014] Furthermore, the mass of the three-pronged suspension bracket is less than 10% of the mass of the test model.

[0015] The beneficial effects of this technical solution are: the test model of the device can complete three-axis rotation with the help of the three-degree-of-freedom hinge, and the test model and the abdominal support rod can move up and down along the axis of the three-pronged suspension bracket to complete the release of the heave freedom, and the test model and the three-pronged suspension bracket can achieve lateral undamped movement under the support of the pneumatic suspension bearing, thereby achieving the purpose of releasing the lateral freedom. The parallel six-degree-of-freedom mechanism base located at the bottom is responsible for the motion compensation of the lateral, heave, roll and pitch freedom. Based on the above structure, the device can realize the coupled motion test capability of the remaining five degrees of freedom except for the forward and backward motion. The realization of the above functions is of great significance to improving the ability of the wind tunnel virtual flight test to restore the real dynamic characteristics of the aircraft model. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 Schematic diagram of the planar structure of the present invention.

[0018] Figure 2 Schematic diagram of the lateral movement and compensation of the model of the present invention.

[0019] Figure 3 Schematic diagram of heave motion and compensation of the model of the present invention.

[0020] Figure 4 Schematic diagram of the rolling motion and compensation of the model of the present invention.

[0021] Figure 5 Schematic diagram of pitch motion and compensation of the model of the present invention.

[0022] Explanation of the accompanying drawings: 1-three-pronged suspension bracket, 2-abdominal support rod, 3-three-degree-of-freedom hinge, 4-pneumatic suspension bearing, 5-bearing bracket, 6-parallel six-degree-of-freedom mechanism base, 7-linear bearing, 8-angle sensor, 9-lateral displacement sensor, 10-heave displacement sensor, 11-test model, 12-measurement and control computer, 13-drive controller. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of 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.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0025] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] Example 1

[0027] like Figure 1-Figure 5As shown, the present invention provides a five-degree-of-freedom virtual flight test device based on motion compensation, including a parallel six-degree-of-freedom mechanism base 6, a three-pronged suspension bracket 1, a test model 11 and a measurement and control computer 12, wherein the parallel six-degree-of-freedom mechanism base 6 is provided with a drive controller 13; two bearing brackets 5 are fixedly mounted on the parallel six-degree-of-freedom mechanism base 6, and pneumatic suspension bearings 4 are fixedly mounted on the bearing brackets 5, and the axes of the pneumatic suspension bearings 4 are parallel to each other, and two pneumatic suspension bearings 4 are fixedly mounted on one of the bearing brackets 5 along its axial direction at intervals, and one pneumatic suspension bearing 4 is fixedly mounted on the other bearing bracket 5. The three-pronged suspension bracket 1 can be slidably inserted on the pneumatic suspension bearing 4, and the specific structure is as follows: the three-pronged suspension bracket 1 includes a main support tube, and three parallel sliding rods are arranged on the side of the main support tube, one of which is located on the opposite side of the other two sliding rods, and the axes of the two sliding rods at the bottom position coincide; each sliding rod can be slidably inserted on the corresponding pneumatic suspension bearing 4, and can achieve non-damping lateral sliding under the support of the pneumatic suspension bearing 4, thereby releasing the model's degree of freedom. The sum of the length of the sliding rod and the outer diameter of the main support tube is greater than the spacing between the two bearing brackets 5, preventing the three-pronged suspension bracket 1 from detaching from the pneumatic suspension bearing 4.

[0028] The main support tube of the three-pronged suspension bracket 1 is longitudinally penetrated by an abdominal support rod 2, and the installation structure is as follows: linear bearings 7 are installed at both ends of the main support tube, and the abdominal support rod 2 is sleeved inside the linear bearing 7. With the help of the linear bearing 7, the test model 11 and the abdominal support rod 2 can move up and down along the axis of the main support tube, thereby releasing the model's heave and sink degrees of freedom. The bottom parallel six degrees of freedom are mainly used to support the above-mentioned construction, and on the other hand, to provide motion compensation for each degree of freedom, thereby expanding the range of motion of each degree of freedom.

[0029] The test model 11 is installed on the top of the abdominal support rod 2 through the three-degree-of-freedom hinge 3. With the help of the three-degree-of-freedom hinge 3, the test model 11 can realize virtual flight including three-degree-of-freedom rotational movement including pitch, yaw and roll. The three-degree-of-freedom hinge 3 is a prior art and will not be described in detail here.

[0030] An angle sensor 8 is fixedly mounted on the test model 11, and a lateral displacement sensor 9 is fixedly mounted on the top of the parallel six-degree-of-freedom mechanism base 6. The installation height of the lateral displacement sensor 9 coincides with the height position of the slide bar at the bottom. A heave displacement sensor 10 is installed at the bottom end of the abdominal support strut 2. The angle sensor 8, the lateral displacement sensor 9, the heave displacement sensor 10 and the drive controller 13 are all connected to the measurement and control computer 12 for signal connection.

[0031] During the wind tunnel virtual flight test, Figure 2As shown, when the model is subjected to aerodynamic force to the left or right, the model and the three-pronged suspension bracket 1 can move horizontally to the left or right as a whole under the support of three pneumatic suspension bearings 4. At this time, the displacement sensor measures the displacement of the three-pronged suspension bracket 1 relative to the parallel six-degree-of-freedom upper platform in real time, and the displacement is transmitted to the measurement and control computer 12 through the signal line. The measurement and control computer 12 calculates the movement of the parallel six-degree-of-freedom mechanism according to the displacement and sends the movement command to the drive controller 13 of the parallel six-degree-of-freedom mechanism base 6 through the communication line, thereby driving the parallel six-degree-of-freedom mechanism base 6 to cooperate with the three-pronged suspension bracket 1 to move left and right in real time, so as to compensate for the lateral displacement and achieve the purpose of extending the lateral displacement stroke. Since the model moves simultaneously with the three-pronged suspension bracket 1, the weight of the bracket itself is added to the model mass. In order to minimize the influence of the mass of the bracket itself on the dynamic characteristics of the model, the three-pronged suspension bracket 1 here is made of all carbon fiber material, and the bracket mass is controlled within 10% of the model mass.

[0032] according to Figure 3 As shown, when the lift of the model changes, it may move upward or downward. At this time, the model and the abdominal support rod 2 can move up and down along the axis of the main support tube at the same time under the constraint of the linear bearing 7. At this time, the heave displacement sensor 10 measures the heave displacement of the abdominal support rod 2 in real time, and the displacement signal is sent to the measurement and control computer 12 through the signal line. The measurement and control computer 12 calculates the heave displacement of the parallel six-degree-of-freedom mechanism and sends the movement command to the drive controller 13 of the parallel six-degree-of-freedom mechanism at the bottom through the communication line, thereby driving the parallel six-degree-of-freedom mechanism base 6 to move up and down in real time with the model, compensating for the model heave movement, and achieving the expansion of the model's heave freedom range.

[0033] according to Figure 4 As shown, when the model rolls under the action of aerodynamic force, the angle sensor 8 located inside the model measures the roll angle of the model, and the roll angle signal is transmitted to the measurement and control computer 12 through the signal line. The computer calculates the corresponding displacement of the parallel six-degree-of-freedom mechanism base 6 according to the angle value and sends it to the drive controller 13, thereby driving the six-degree-of-freedom mechanism to cooperate with the model to perform rolling motion, thereby achieving the purpose of compensating the model roll and expanding the rolling freedom range.

[0034] Similarly, according to Figure 5 As shown, when the model undergoes pitch motion under the action of aerodynamic force, the angle sensor 8 located inside the model measures the pitch angle of the model, and the pitch angle signal is transmitted to the measurement and control computer 12 through the signal line. The computer calculates the corresponding displacement of the parallel six-degree-of-freedom mechanism base 6 according to the angle value, and the displacement is sent to the drive controller 13 through the communication line, thereby driving the parallel six-degree-of-freedom mechanism base 6 to cooperate with the model to perform pitch motion, thereby achieving the purpose of compensating the model pitch angle and expanding the pitch freedom range.

[0035] In summary, this solution firstly realizes the five-degree-of-freedom motion function including lateral movement, heave, roll, pitch, and yaw. Secondly, the four degrees of freedom of lateral movement, heave, roll, and pitch are compensated by the parallel six-degree-of-freedom mechanism base 6, and the travel range of the above four degrees of freedom is expanded (the yaw freedom range of the virtual flight test technology can reach 360° without infinite position, so there is no need to consider the travel expansion problem of the yaw freedom).

[0036] Compared with the previous four-degree-of-freedom virtual flight test technology, the present invention cleverly uses the pneumatic suspension bearing 4 to achieve the undamped lateral movement of the model. The realization of this function is of great significance for restoring the lateral dynamic characteristics of the aircraft through experiments, such as simulating the Dutch roll mode that couples yaw, roll and lateral movement. Secondly, on the basis of realizing the above-mentioned five-degree-of-freedom movement, the auxiliary compensation movement of the parallel six-degree-of-freedom mechanism is used to expand the movement range of four of the degrees of freedom. The realization of this function is helpful for dynamic testing of large-scale movement for a single degree of freedom.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A five-degree-of-freedom virtual flight test device based on motion compensation, characterized in that: It includes a parallel six-degree-of-freedom mechanism base, a three-pronged suspension bracket, a test model and a measurement and control computer, wherein the parallel six-degree-of-freedom mechanism base is provided with a drive controller; a pneumatic suspension bearing is mounted on the top end of the parallel six-degree-of-freedom mechanism base, and the three-pronged suspension bracket can be slidably inserted on the pneumatic suspension bearing; a belly support strut is installed longitudinally through the three-pronged suspension bracket, the test model is installed on the top end of the belly support strut through a three-degree-of-freedom hinge, an angle sensor is fixedly installed on the test model, a lateral displacement sensor is fixedly installed on the top end of the parallel six-degree-of-freedom mechanism base, a heave displacement sensor is installed on the bottom end of the belly support strut, and the angle sensor, the lateral displacement sensor, the heave displacement sensor and the drive controller are all connected with the measurement and control computer signal.

2. The five-degree-of-freedom virtual flight test device based on motion compensation according to claim 1, characterized in that: Two bearing brackets are fixedly mounted on the base of the parallel six-degree-of-freedom mechanism, and the pneumatic suspension bearings are fixedly mounted on the bearing brackets. The axes of the pneumatic suspension bearings are parallel to each other, and two pneumatic suspension bearings are fixedly mounted on one of the bearing brackets along the axial direction thereof.

3. The five-degree-of-freedom virtual flight test device based on motion compensation according to claim 2, characterized in that: The three-pronged suspension bracket includes a main support tube, and three parallel sliding rods are arranged on the side of the main support tube, one of the sliding rods is located on the side opposite to the other two sliding rods, and each of the sliding rods can be slidably inserted on the corresponding pneumatic suspension bearing.

4. The five-degree-of-freedom virtual flight test device based on motion compensation according to claim 3 is characterized in that: Linear bearings are installed at the two ports of the main support tube, and the abdominal support rod is sleeved inside the linear bearings.

5. The five-degree-of-freedom virtual flight test device based on motion compensation according to claim 3, characterized in that: The sum of the length of the sliding rod and the outer diameter of the main support tube is greater than the distance between the two bearing supports.

6. The five-degree-of-freedom virtual flight test device based on motion compensation according to claim 3, characterized in that: The axes of the two sliding rods located at the bottom positions coincide with each other.

7. The five-degree-of-freedom virtual flight test device based on motion compensation according to claim 3, characterized in that: The installation height of the lateral displacement sensor coincides with the height position of the sliding rod at the bottom end.

8. The five-degree-of-freedom virtual flight test device based on motion compensation according to claim 1, characterized in that: The three-pronged suspension bracket is made of carbon fiber material.

9. The five-degree-of-freedom virtual flight test device based on motion compensation according to claim 8, characterized in that: The mass of the three-pronged suspension bracket is less than 10% of the mass of the test model.

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