Attack angle and yaw combined system for test piece in high-altitude cabin

Abstract

The invention discloses an attack angle and yaw combined system for a test piece in a high altitude cabin, and the whole system comprises an attack angle mechanism, a yaw mechanism, a control device, measurement and control software, a pipeline and accessories, a cable and accessories, a heat insulation structure and the like, and the attack angle mechanism comprises a movable platform, a static platform, a rotating shaft system, an angle adjustment device, a bearing device and the like. The mechanism is provided with a locking device, angle measurement and closed-loop feedback, and is provided with a limiting protection switch function; the yaw mechanism comprises a movable platform, a static platform, a rotating shaft system, a bearing device, an angle adjusting driving cylinder and the like, and heat insulation measures of the system are considered. The yaw mechanism is also provided with a locking device, angle measurement and closed-loop feedback, and is provided with a limiting protection switch function.

Description

Technical Field

[0001] The invention relates to an attack angle and yaw combined system, in particular to an attack angle and yaw combined system of a test piece inside a high-altitude test cabin. Background Art

[0002] High-altitude test chambers are equipment used to simulate various environmental factors of aircraft in high-altitude flight, and are widely used in research and testing in the aerospace field. This test chamber can test the performance of aircraft components or overall structures under specific high-altitude conditions, including the influence of parameters such as air pressure, temperature, wind speed, and attitude. However, in the prior art, high-altitude test chambers have conducted few tests on variable-attitude aircraft, and the adjustment of their angle of attack and yaw is often not flexible enough, and it is impossible to simulate complex flight motion states at the same time, which limits the comprehensiveness and accuracy of the test.

[0003] In order to solve the above problems, it is necessary to develop a system that can accurately adjust the angle of attack and yaw of the test piece inside the high-altitude test chamber. The system should be able to achieve multi-angle positioning of the test piece in the high-altitude environment to simulate the aerodynamic effects under different flight conditions. In addition, the system design should ensure high repeatability and accuracy in order to obtain more reliable test data.

[0004] The current high-altitude test chamber technology mainly focuses on the accuracy of environmental simulation and the performance of the test piece, but the dynamic attitude adjustment capability of the test piece itself is relatively weak. Therefore, the development of a test system that integrates the angle of attack and yaw angle adjustment functions can not only improve the applicability and flexibility of the test, but also significantly enhance the accuracy of the data, thereby promoting the in-depth development of research in the field of high-altitude simulation tests. Summary of the invention

[0005] The technical problem to be solved by the present invention is to adjust and control the angle of attack of the test piece during the test in the angle of attack mechanism, that is, to adjust the pitch angle of the test piece, simulate different flight attitudes and evaluate the performance of the engine under these conditions. In the yaw mechanism (2), the test piece is rotated around its vertical axis during the test to simulate the yaw action in flight. This system can accurately adjust the yaw angle from negative angle to positive angle by precisely controlling the angle change of the test piece on the horizontal plane.

[0006] To solve the above problems, the present invention is implemented by the following scheme: the whole system for changing the angle of attack includes an angle of attack mechanism including a push rod, a control device, measurement and control software, pipelines and accessories, cables and accessories, thermal insulation structure, etc. The mechanism has a locking device, angle measurement and closed-loop feedback, and is equipped with a limit protection switch function; the yaw mechanism (2) is composed of a yaw mechanism including a push rod and a steering gear, a bearing device, auxiliary components, etc., and thermal insulation measures of the system are considered. The operator issues a control instruction through the upper computer human-machine interface, and then transmits the control command to the lower controller, which controls the servo system of each degree of freedom, and then drives each sub-mechanism to complete the corresponding movement, thereby completing the angle of attack movement or steering requirements of the test piece model.

[0007] Due to the adoption of the above scheme, the present invention has the following advantages compared with the prior art: the system adjusts the angle of attack and the yaw angle simultaneously through the push rod and the steering gear, thereby improving the flexibility and accuracy of the test; it is easy to operate and can achieve fast and accurate angle adjustment; it can enhance the accuracy and real-time performance of high-altitude test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 Overall combined system plan

[0009] Figure 2 Combination system structure diagram

[0010] Figure 3 Attack angle mechanism composition diagram

[0011] Figure 4 Schematic diagram of the pitch axis

[0012] Figure 5 Structural changes of the pitch mechanism

[0013] Figure 6 Y-axis lifting mechanism diagram

[0014] Figure 7 X-axis structure diagram

[0015] Figure 8 Overall diagram of yaw mechanism

[0016] Fig. 9 Structural diagram of yaw mechanism

[0017] Fig.10 Horizontal yaw diagram

[0018] Fig.11 Control system composition diagram

[0019] Fig.12 Software function module diagram

[0020] In the picture

[0021] 1. Angle of attack mechanism 2. Yaw mechanism 3. Control system

[0022] 4. Accessories 5. Test piece 6. Attack angle dynamic platform

[0023] 7. Attack angle static platform 8. Attack angle shaft system 9. Attack angle adjustment device

[0024] 10. Attack angle bearing device 11. Locking device A 12. Angle measurement A

[0025] 13. Closed loop feedback A 14. Limit protection switch A 15. Yaw dynamic platform

[0026] 16. Yaw static platform 17. Yaw shaft system 18. Yaw bearing device

[0027] 19. Yaw angle adjustment driver 20. Locking device B 21. Angle measurement B

[0028] 22. Closed loop feedback B 23. Limit protection switch B 24. X-axis translation mechanism

[0029] 25.Y-axis lifting mechanism 26.Pitch mechanism 27.Motor drives the lead screw

[0030] 28. AC servo motor 29. Screw-nut 30. Screw drive

[0031] 31. Electric push rod 32. Bottom plate 33. Roller

[0032] 34. Cylindrical guide rail 35. Slider 36. Industrial computer

[0033] 37.PLC 38.Lifter push rod 39.Locking push rod

[0034] 40.Z-direction translation mechanism DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0036] 1. Angle of attack movement

[0037] The angle of attack motion of the test piece model can be regarded as the circular motion of the test piece model around a specified rotation axis. The angle of attack mechanism designed in this paper includes an X-axis horizontal motion mechanism (24), a Y-axis lifting mechanism (25) and a pitch mechanism (26), wherein the pitch mechanism (26) is responsible for changing the pitch angle of the test piece model. When the pitch angle changes, the coordinates of the specified rotation axis on the test piece model will change. At this time, it is necessary to ensure that the coordinates of the point remain unchanged through the movement of the X-axis horizontal mechanism (24) and the Y-axis lifting mechanism (25). In this way, the circular motion of the test piece model around a specified rotation axis on the test piece is completed through the movement of three degrees of freedom. After analysis, it can be seen that the movement of the X-axis translation mechanism (24), the Y-axis lifting mechanism (25) and the pitch mechanism (26) can synthesize the circular motion of the test piece model around the specified rotation axis.

[0038] The designed angle-of-attack mechanism (1) is composed of a mechanical system and a control system. The mechanical system is a three-degree-of-freedom mechanism consisting of an X-axis translation mechanism (24), a Y-axis lifting mechanism (25), and a pitch mechanism (26). It provides support for the test piece in the test and adjusts its posture. It is the core of the angle-of-attack mechanism (1). It is controlled by a control system (3) with a computer as the core. The two parts work together to provide the test piece model with three degrees of freedom (X-axis horizontal, Y-axis vertical, pitch) movement. The composition of the angle-of-attack mechanism (1) structure is as follows: Figure 1 shown.

[0039] The angle of attack mechanism (1) decomposes the angle of attack motion into three independent motions of freedom, namely, pitch motion, lifting motion in the Y direction, and horizontal motion in the X direction. Since the system has high requirements for accuracy, it is more appropriate to use a motor-driven lead screw (27) for transmission. Since there are no other additional restrictions on the X-axis translation direction, an AC servo motor (28) is directly selected as the prime mover and the lead screw-nut (29) is used for transmission by rotation. However, the pitch motion and the lifting motion of the Y axis are limited by the installation space, so an electric push rod (31) with the same principle as the lead screw drive (30) is selected to drive, thereby saving installation space, such as Figure 2 shown.

[0040] The function of the X-direction mechanism (24) is to realize the horizontal movement of the angle-of-attack mechanism (1) along the X-direction, thereby realizing the X-direction movement of the test piece (5). The X-direction mechanism is composed of a base plate (32), a roller (33), a limit device (14) and a driving screw (27). The X-direction mechanism is connected to the ground through the base plate (32) to provide fixed support for the angle-of-attack mechanism (1). The X-direction mechanism (24) is driven by the roller (33) to move on the guide rail. The function of the Y-direction lifting mechanism (25) is to realize the lifting movement of the test piece (5) in the vertical direction. The mechanism adopts a center-of-gravity driving method guided by a cylindrical guide rail (34). The driving principle of the Y-direction lifting mechanism (25) is to use the guide rail and the slider (35) as a guide device, and the electric push rod (31) as a power device to drive the pitch mechanism (26) and the test piece (5) to perform vertical lifting movement. Both the X-direction mechanism (24) and the Y-direction mechanism (25) can change the position of the lateral rotation center of the test piece in the angle of attack mechanism (1). The pitch mechanism (26) realizes the smooth and accurate pitching movement of the test piece (5) model. One end of the angle of attack dynamic platform (6), i.e., the mounting plate of the test piece (5), is connected to the angle of attack rotation axis system (8), and the other end is connected to the extension axis of the electric push rod (31), and the pitching movement of the test piece model is completed by the extension and contraction of the electric push rod (31).

[0041] The attack angle mechanism (1) controls the X-direction, Y-direction and pitch motion of the test piece model to realize the attack angle motion around a certain rotation axis. The control system (3) adopts a two-level control scheme with an industrial computer (36) as the upper computer and a PLC (37) as the lower computer.

[0042] The mechanical structure system is an important component of the angle-of-attack mechanism (1). Its strength, stiffness, dynamic performance and thermal performance all have a significant impact on the overall performance and functional reliability of the angle-of-attack mechanism (1). Structural calculations are required during the design.

[0043] 1) Design and calculation of pitch mechanism (26)

[0044] The pitch mechanism (26) is an indispensable and important part of the angle of attack mechanism (1), and its function is to achieve a smooth and accurate pitch motion of the test piece. Figure 4 shown.

[0045] 2) Driving element travel

[0046] The size of the pitch mechanism (26) is determined according to the rotation angle range of the overall attack angle mechanism (1), and the stroke of the driving element can be calculated to be 1624 mm through complex geometric relationships.

[0047] 2) Driving force analysis

[0048] Since the angle of attack mechanism (1) is relatively complex, its force condition is simplified and the driving force that the driving element should have is calculated to be 27600N.

[0049] 4) Driving component selection

[0050] The electric push rod (31) is a modular product that converts the rotary motion of the servo motor (27) into linear motion, which fully utilizes the advantages of the servo motor (27) and can achieve precise speed, position and thrust control. The servo electric cylinder (28) has the advantages of high control accuracy, thrust can be maintained at any position, high dynamic response time, high acceleration, high rigidity, impact resistance, ultra-long life, simple operation and maintenance, low noise, etc.

[0051] 5) Design of the shaft

[0052] Since the force of the angle of attack mechanism (1) is relatively complex, with thrusts in different directions and the gravity of the model itself, in order to facilitate the design and calculation of the rotating shaft (8), the following simplification is made: the thrust and the gravity of the test piece (5) act on the mandrel and all forces are in the same plane. The diameter of the rotating shaft is finally selected as 160 mm.

[0053] 6) Design and calculation of Y-axis lifting mechanism (25)

[0054] The Y-direction lifting mechanism (25) needs to lift a large load during operation, including the weight of the pitch mechanism (26) and the weight of the test piece (5), and the position of the load center of gravity of the Y-direction lifting mechanism (25) will change when the test piece model is different. In view of the above problems, the mechanism adopts a double drive method guided by a cylindrical guide rail (34).

[0055] It is known that the mass of the moving part is 6t, the moving stroke is 1250mm, and the maximum running speed is 62.5mm / s. The lift push rod (38) is composed of a screw lift, a motor, a reducer and other modules. Its high sealing protection level can ensure that it can adapt to harsh use environments and can achieve heavy-load lifting movements in the industrial field. The lift push rod (38) driven by a single motor can have a lifting accuracy of 0.1mm, simple control and high reliability.

[0056] The maximum push-pull load of the lift push rod (38) can reach 20 tons, the maximum speed can reach 100 mm / s, and the stroke can reach 2.5 meters, which can fully meet the power requirements of the Y-direction lifting mechanism (25).

[0057] 7) Design and calculation of X-axis translation mechanism (24)

[0058] The X-direction horizontal motion mechanism (24) is located at the bottom layer of the angle-of-attack mechanism (1). In addition to providing fixed support for the angle-of-attack mechanism (1), its main function is to realize the translation of the angle-of-attack mechanism (1) along the X-direction, so that the model can be adjusted in the X-direction. The X-direction motion platform (24) is driven by the lead screw-nut (29) to move the roller (33) on the guide rail. The roller (33) in the X-direction mechanism (24) is used to support other structures of the angle-of-attack mechanism and provide a guiding function for it. Since it has a large load and a harsh working environment, pay attention to the protection of the roller (33) when using it.

[0059] 8) Selection of lead screw and servo motor (27)

[0060] According to the calculation, the results of the preselection of the lead screw (27) and its specific parameters are shown in Table 1. Considering that the lead screw (29) has a long stroke, the X-direction translation mechanism (24) requires high precision, and taking into account factors such as installation precision and cost, the support method adopted by the X-direction translation mechanism (24) is a "fixed-support" method.

[0061] 9) Locking mechanism (11) Design

[0062] The function of the locking mechanism (11) is to lock the degrees of freedom of the angle-of-attack mechanism (1) after the test piece (5) is sent to a certain position, thereby fixing the spatial position of the test piece (5) for the purpose of conducting experiments. The locking mechanism (11) uses a locking push rod (39) as a power source, first converting the push rod extension movement of the locking push rod (39) into the swing of the locking rod and the upper shaft connecting rod, and then driving the stud to perform thread rotation movement, so that the stud exerts force on the locking sleeve, and the locking sleeve deforms and locks the locking shaft, thereby achieving the purpose of locking. In addition, the stud has a self-locking ability and can maintain a locked state.

[0063] Table 1 Ball screw parameters

[0064]

[0065] Taking the safety factor as 2, the thrust of each electric push rod (31) is 33320N. The calculated length of the rotating platform of the angle-of-attack mechanism (1) is 6.6m, and the stroke of the driving element is 1624mm. The diameter of the horizontal rotating shaft is 160mm, and the initial distance between the horizontal rotating shaft and the floor is 1.4m. After measurement, the rotation angle range of the angle-of-attack mechanism (1) is + / -10°, and the measurement accuracy exceeds 0.02°.

[0066] 2. Yaw motion

[0067] The yaw mechanism (2) decomposes the yaw motion into two independent motions of freedom, namely, the turning motion and the horizontal motion in the Z direction. Since the system has high requirements for precision, it is more appropriate to use a motor to drive the turntable (17) to rotate. Since there are no other additional restrictions on the Z-axis translation direction, an AC servo motor (28) is directly selected as the prime mover and the screw-nut (29) is used for transmission.

[0068] like Fig. 9 As shown, the mechanical part of the yaw mechanism (2) is composed of two main sub-devices, namely the Z-direction translation mechanism (40) and the steering mechanism (15). The two sub-devices are connected in series to form the entire yaw mechanism (2), thereby ensuring the flexibility of the yaw mechanism (2) and the yaw range of the test piece model. The basic principle of steering is similar to that of the angle of attack mechanism (1).

[0069] During the design of the test piece (5), after the turning radius of the test piece (5) is determined, the yaw angle can be determined. When designing the mechanism, not only the available steering angle should be considered, but also the situation where the applied force can be greater than the required force should be considered, and the available turning angle should be reasonably limited. After the size of the turning angle is determined, the steering method should be reasonably selected based on the physical connection between the installation and the rear end support link (31) of the mechanism and the servo motor (27), the specific requirements of the structural clearance, stiffness, damping, etc.

[0070] The function of the Z-direction mechanism (40) is to realize the horizontal movement of the yaw mechanism (2) along the Z direction, thereby realizing the Z-direction movement of the test piece (5). The Z-direction mechanism (40) is composed of a base plate (32), a roller (33), a limit device (14) and a driving screw (27). The Z-direction mechanism (40) is similar to the X-direction mechanism (24), and provides a high-precision guiding function, and can change the position of the horizontal rotation center of the test piece (5) in the yaw mechanism (2).

[0071] The turning angle of the turntable turning mechanism (17) is usually small. If a larger traction turning angle is required, the rear telescopic connecting rod (31) needs to be driven to rotate in coordination so that the front end rotating shaft (19) can turn at a larger angle. This type of turntable (15) is small and has a simple structure.

[0072] The yaw mechanism (2) controls the Z-direction and steering motion of the test piece (5) to achieve yaw motion around a certain rotation axis. The control system (3) also uses an industrial computer (36) as a host computer and a PLC (37) as a secondary control scheme for a lower computer.

[0073] The structural performance estimation mainly calculates the rotational driving capacity of the turntable (15) and the bearing capacity of the supporting connecting rod (31). In terms of rotational driving capacity, it is assumed that the time from the start to the rotation speed is 8s; the angular velocity is ω = 1rad / s, then the angular acceleration β = 0.125rad.s2 ; Moment of inertia J = 0.5MR 2 =9900kg.m 2 , torque T = Jβ = 1237N·m, the turntable (15) can meet the requirements. After the structure basically meets the requirements, the structure is checked. The check results show that the yaw mechanism (2) meets the design requirements. The height of the turntable (15) in the steering mechanism of the yaw mechanism (2) is 0.3m, the diameter is 0.7m, and the initial distance between the turntable (15) and the floor (32) is 1m. The rotation angle range of the yaw mechanism (2) is + / -8°, and the measurement accuracy exceeds 0.02°.

[0074] 3. Control system (3)

[0075] In the whole combined system, considering many factors, this control system (3) decided to adopt a two-level control system scheme with an industrial computer (36) as the upper computer and a PLC (37) as the lower computer. This meets the requirements of the control system in terms of applicability, reliability, and economy. The basic scheme of the control system is as follows: Fig.11 shown.

[0076] The control process is as follows: PLC (37) is a lower controller responsible for collecting and processing various data collected by the sensor, and interacting with the upper industrial computer through the PROFIBUS-DP bus. The upper computer interface is configured using WINCC software to intuitively display the data collected by the field sensor system, and to operate the relevant parameters through data interaction with the PLC (37), thereby realizing the motion control and monitoring of the motion mechanism. The sensors installed on each degree of freedom upload the collected data to the controller, and compare the collected data with the input value of the upper computer, and then use appropriate algorithms to process the data, and then transmit the control signal obtained after processing to the driver, and finally realize the control of the prime mover of each degree of freedom. When the mechanism is running, the limit switch (14) can make the mechanism run within a safe range. In this way, the closed-loop control of the motion mechanism system is completed, and the attack angle and yaw motion of the test piece are accurately controlled according to the instructions of the operator.

[0077] This motion combination mechanism system controls the X, Y, Z, steering and pitching motions of the test piece model to achieve the angle of attack and yaw motions around a certain rotation axis. Since the control accuracy requirements of the system (3) are relatively high, it is necessary to use an intelligent controller in the host computer to control the motion speed, position, etc.

[0078] The hardware design of the control system (3) is as follows:

[0079] 1) Main Controller

[0080] The basic parameters of the industrial computer of this system are 1G memory, 16QG hard disk, and multiple disk drives, as well as 2 USB and PS / 2 keyboard I / O interfaces, and 5 PCI slots, which makes it very convenient to expand the system. In addition, an optional LCD monitor is used to display various graphics and texts. The industrial computer is installed with WINDOWS system, and printers and other devices can be connected when necessary to expand the functions required by users.

[0081] The CPU built-in I / O used by the lower PLC of this system can be connected to the process signal, and the PROFIBUS master-slave interface can control the servo motor driver and can also be connected to the ET200 remote module. The CPU can communicate with the upper computer through the PROFIBUS protocol, and its diagnostic function and self-protection technology make the control system highly reliable.

[0082] 2) Sensor system

[0083] According to the control requirements, a closed linear grating ruler is used as the detection device for the mechanism position, and the displacement signal of the mechanism is converted into a pulse signal, which is then transmitted to the PLC to realize the closed-loop servo control of the platform control. The displacement sensor used in this system has an accuracy level of 0.03mm, and the maximum measurable moving speed is <180m / min, which meets the requirements of high-precision positioning of the mechanism.

[0084] In order to ensure the reliability of the locking mechanism (20), a flameproof magnetostrictive displacement sensor is installed in parallel with the push rod of the locking mechanism (20) to measure the stroke of the locking push rod (39), thereby judging whether the locking mechanism is safely locked.

[0085] In order to ensure accurate positioning of the pitch mechanism, an inclination sensor is used to detect the inclination of the model mounting plate. The sensitivity error of the sensor is ±0.5%, the range is ±10°, and the full-scale voltage is 5V. This sensor based on the principle of capacitive micro-pendulum can fully meet the requirements of this system for inclination detection.

[0086] The software design of the control system (3) is as follows:

[0087] According to the functional requirements analysis of the control software, the functional modules of the host computer software are preliminarily determined, such as Fig.12 shown.

[0088] The upper computer software mainly includes the main interface, system parameter setting interface and motion setting interface. The main interface mainly displays the on-site monitoring screen and system information. Through the main interface, you can enter the other two sub-interfaces, and through the main interface, you can control the entire system. The system parameter setting interface is mainly responsible for inputting the position of the rotation center and the size of the test piece (5). The motion setting interface is mainly responsible for selecting the operation mode and setting the motion speed and motion mechanism angle.

[0089] The contents not described in detail in the present invention are well known to those skilled in the art.

Claims

1. A combined system of attack angle and yaw of a test piece in a high altitude cabin, characterized in that: The angle of attack and yaw combined system comprises an angle of attack mechanism (1), a yaw mechanism (2), a control system (3), an auxiliary component (4), etc., wherein the angle of attack mechanism (1) mainly functions to adjust and control the angle of attack of the test piece (5) during the test, that is, to adjust the pitch angle of the test piece (5), simulate different flight attitudes and evaluate the performance of the engine under these conditions. The system allows the test piece (5) to rotate around its horizontal axis during the test through a precise mechanical device to achieve adjustment from a negative angle to a positive angle; the yaw mechanism (2) of the test piece (5) mainly functions to allow the test piece (5) to rotate around its vertical axis during the test to simulate the yaw action in flight. This system can accurately adjust the yaw angle from a negative angle to a positive angle by precisely controlling the angle change of the test piece (5) on the horizontal plane.

2. The angle of attack mechanism (1) according to claim 1, characterized in that: The invention comprises an angle of attack dynamic platform (6), an angle of attack static platform (7), an angle of attack rotating shaft system (8), an angle of attack angle adjustment device (9), an angle of attack bearing device (10) and the like. The mechanism also has a locking device A (11), an angle measurement A (12) and a closed-loop feedback A (13), and is equipped with a limit protection switch A (14) function.

3. The yaw mechanism (2) according to claim 1, characterized in that: It includes a yaw dynamic platform (15), a yaw static platform (16), a yaw shaft system (17), a yaw bearing device (18), a yaw angle adjustment driver (19), etc. The yaw mechanism (2) also has a similar locking device B (20), an angle measurement B (21) and a closed-loop feedback B (22), and is configured with a limit protection switch B (23) function.

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