A tilt-rotor UAV rotor nacelle aerodynamic measurement system and method

Abstract

The invention belongs to the technical field of unmanned aerial vehicle testing, and discloses a tilt-rotor unmanned aerial vehicle rotor nacelle aerodynamic measurement system and method, comprising a test bench, a six-component strain balance, a nacelle support and a data acquisition and processing module; the six-component strain balance is arranged at the top of the test bench, the nacelle support is arranged at the top of the six-component strain balance, and the rotor nacelle to be measured is installed on the top side of the nacelle support; the six-component strain balance comprises a balance body and eight measuring elements; the balance body is arranged at the top of the test bench, and the nacelle support is installed at the top center of the balance body; four measuring elements are respectively arranged at the four corners of the balance body, and the remaining four measuring elements are respectively arranged at the four sides of the balance body; the eight measuring elements are all connected to the data acquisition and processing module; the invention realizes accurate measurement of the aerodynamic parameters of the rotor nacelle to be measured under different working conditions, and effectively improves the practicability and adaptability of the measurement system.

Description

Technical Field

[0001] The invention belongs to the technical field of unmanned aerial vehicle testing, and in particular relates to a system and method for measuring aerodynamic force of a rotor nacelle of a tilt-rotor unmanned aerial vehicle. Background Art

[0002] Tilt-rotor UAV is a new type of UAV that combines the advantages of fixed-wing aircraft and helicopters. Compared with fixed-wing aircraft, it can take off and land vertically in a limited space, has low runway requirements and good site adaptability. Compared with traditional helicopters, it has a faster cruising speed and longer range, less vibration, lower fuel consumption and a larger payload. Therefore, tilt-rotor UAV has a wider flight envelope and broad application prospects.

[0003] The tilt-rotor UAV combines the rotor of a helicopter and the propeller of a fixed-wing aircraft into one, and has the vertical take-off and landing flight mode of a helicopter and the horizontal flight mode of a fixed-wing aircraft. Among them, the rotor nacelle is the key core component of the tilt-rotor aircraft. Before the whole machine is assembled, a large number of aerodynamic performance tests must be carried out on the ground for the rotor nacelle. At present, the existing rotor test bench is mainly used for aerodynamic testing of the rotor nacelle of a helicopter. The total pitch and cyclic pitch cannot usually be changed during the test. Therefore, it cannot meet the aerodynamic measurement needs of the rotor nacelle of the tilt-rotor aircraft under different tilt angles, total pitch and cyclic pitch conditions. Summary of the invention

[0004] In view of the technical problems existing in the prior art, the present invention provides a tilt-rotor UAV rotor nacelle aerodynamic measurement system and method to solve the technical problem that the existing rotor test bench cannot meet the aerodynamic measurement requirements of the tilt-rotor aircraft rotor nacelle under different tilt angles, total pitch and cyclic pitch conditions.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention provides a tilt-rotor UAV rotor nacelle aerodynamic force measurement system, comprising a test bench, a six-component strain balance, a nacelle support and a data acquisition and processing module; the six-component strain balance is arranged at the top of the test bench, the nacelle support is arranged at the top of the six-component strain balance, and the rotor nacelle to be measured is installed on the top side of the nacelle support;

[0007] The six-component strain balance includes a balance body and eight measuring elements; the balance body is arranged at the top of the test bench, and the nacelle support is installed at the top center of the balance body; four of the measuring elements are respectively arranged at the four corners of the balance body, and the remaining four measuring elements are respectively arranged at the four sides of the balance body; the eight measuring elements are connected to the data acquisition and processing module;

[0008] Among them, the measuring element is used to sense the stress changes acting on the balance body under the preset tilt angle, collective pitch or cyclic pitch variation conditions of the rotor nacelle to be tested and output it in the form of an electrical signal to obtain voltage measurement data; the data acquisition and processing module is used to obtain and calculate the aerodynamic parameters of the rotor nacelle to be tested under the preset tilt angle, collective pitch or cyclic pitch variation conditions based on the voltage measurement data.

[0009] Furthermore, the eight measuring elements have the same structure and all adopt a full-bridge circuit module; wherein the full-bridge circuit module is a Wheatstone full-bridge circuit formed by connecting four strain gauges.

[0010] Furthermore, the aerodynamic parameters of the rotor nacelle to be measured under the preset tilt angle, collective pitch or cyclic pitch condition are specifically:

[0011]

[0012]

[0013] in, is the six-component aerodynamic matrix of the rotor nacelle to be measured relative to the six-component strain balance; is the principal coefficient matrix of the six-component strain balance; is the coefficient matrix of the first-order interference term of the six-component strain balance; is the first-order interference matrix of the six-component strain balance; is the coefficient matrix of quadratic interference term of six-component strain balance; is the quadratic interference matrix of the six-component strain balance; for y The voltage increment corresponding to the aerodynamic force; For around z The voltage increment corresponding to the shaft aerodynamic torque; For around x The voltage increment corresponding to the shaft aerodynamic torque; for x The voltage increment corresponding to the aerodynamic force; for z The voltage increment corresponding to the aerodynamic force; For around y The voltage increment corresponding to the shaft aerodynamic torque;

[0014] in, y Voltage increment corresponding to the aerodynamic force , around z Voltage increment corresponding to the shaft aerodynamic torque , around x Voltage increment corresponding to the shaft aerodynamic torque , xVoltage increment corresponding to the aerodynamic force , z Voltage increment corresponding to the aerodynamic force And around y Voltage increment corresponding to the shaft aerodynamic torque The voltage measurement data are respectively used for calculation.

[0015] Furthermore, the test bench includes a main support bench and a transfer bench; the main support bench is vertically fixed on the ground or the test bench, the transfer bench is installed on the top of the main support bench, and the six-component strain balance is installed on the top of the transfer bench.

[0016] The present invention also provides a tilt-rotor UAV rotor nacelle aerodynamic force measurement method, using the tilt-rotor UAV rotor nacelle aerodynamic force measurement system;

[0017] The tilt-rotor UAV rotor nacelle aerodynamic measurement method comprises:

[0018] Adjusting and controlling the tilt angle of the rotor nacelle to be tested so that the rotor nacelle to be tested is at a preset tilt angle;

[0019] When the rotor nacelle to be measured is at a preset tilt angle, obtaining voltage measurement data output by eight measuring elements in the six-component strain balance to obtain an initial output voltage reading;

[0020] Adjusting and controlling the collective pitch or cyclic pitch of the rotor nacelle to be tested so that the rotor nacelle to be tested is in a preset collective pitch or cyclic pitch state;

[0021] When the rotor nacelle to be measured is in a preset collective pitch or cyclic pitch state, obtaining voltage measurement data output by eight measuring elements in the six-component strain balance to obtain a final output voltage reading;

[0022] The aerodynamic parameters of the rotor nacelle to be tested under a preset tilt angle, collective pitch or cyclic pitch condition are calculated according to the initial output voltage reading and the final output voltage reading.

[0023] Further, according to the output voltage initial reading and the output voltage final reading, the process of calculating the aerodynamic parameters of the rotor nacelle to be tested under the preset tilt angle, collective pitch or cyclic pitch condition comprises the following steps:

[0024] According to the output voltage initial reading and the output voltage final reading, a voltage increment corresponding to the aerodynamic performance of the rotor nacelle to be tested under different collective pitch or cyclic pitch variation conditions is calculated;

[0025] The aerodynamic parameters of the rotor nacelle to be tested under a preset tilt angle, collective pitch or cyclic pitch condition are calculated according to the voltage increment corresponding to the aerodynamic performance of the rotor nacelle to be tested under different collective pitch or cyclic pitch condition.

[0026] Furthermore, the voltage increment corresponding to the aerodynamic performance of the rotor nacelle to be measured under different collective pitch or cyclic pitch conditions is specifically:

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033] in, for y The voltage increment corresponding to the aerodynamic force; For around z The voltage increment corresponding to the shaft aerodynamic torque; For around x The voltage increment corresponding to the shaft aerodynamic torque; for x The voltage increment corresponding to the aerodynamic force; for z The voltage increment corresponding to the aerodynamic force; For around y The voltage increment corresponding to the shaft aerodynamic torque; It is the difference between the final output voltage reading and the initial output voltage reading of the first measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the second measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the third measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the fourth measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the fifth measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the sixth measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the seventh measuring element; It is the difference between the final output voltage reading and the initial output voltage reading of the eighth measuring element.

[0034] Further, according to the voltage increment corresponding to the aerodynamic performance of the rotor nacelle to be tested under different collective pitch or cyclic pitch variation conditions, the process of calculating the aerodynamic parameters of the rotor nacelle to be tested under the preset tilt angle, collective pitch or cyclic pitch variation conditions is as follows:

[0035]

[0036]

[0037] in, is the six-component aerodynamic matrix of the rotor nacelle to be measured relative to the six-component strain balance; is the principal coefficient matrix of the six-component strain balance; is the coefficient matrix of the first-order interference term of the six-component strain balance; is the first-order interference matrix of the six-component strain balance; is the coefficient matrix of quadratic interference term of six-component strain balance; is the quadratic interference matrix of the six-component strain balance; for y The voltage increment corresponding to the aerodynamic force; For around z The voltage increment corresponding to the shaft aerodynamic torque; For around x The voltage increment corresponding to the shaft aerodynamic torque; for x The voltage increment corresponding to the aerodynamic force; for z The voltage increment corresponding to the aerodynamic force; For around y The voltage increment corresponding to the shaft aerodynamic torque.

[0038] Furthermore, the tilt angle of the rotor nacelle to be tested is adjusted and controlled so that the rotor nacelle to be tested is located before a preset tilt angle, and a static calibration step is also included;

[0039] The static calibration step is specifically as follows:

[0040] Perform static calibration on the six-component strain balance to obtain the main coefficient matrix of the six-component strain balance , the coefficient matrix of the first-order interference term of the six-component strain balance And the quadratic interference coefficient matrix of the six-component strain balance .

[0041] Further, when the rotor nacelle to be tested is in a preset collective pitch or cyclic pitch state, the rotor nacelle to be tested is in a rated speed operation state.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The tilt-rotor UAV rotor nacelle aerodynamic force measurement system provided by the present invention installs the rotor nacelle to be measured on a six-component strain balance through a nacelle support, uses the six-component strain balance to sense the voltage measurement data of the rotor nacelle to be measured under a preset tilt angle, total pitch or cyclic pitch change working condition, and calculates the aerodynamic force parameters of the rotor nacelle to be measured under the preset tilt angle, total pitch or cyclic pitch change working condition according to the acquired voltage measurement data, thereby realizing accurate measurement of the aerodynamic force parameters of the rotor nacelle to be measured under different working conditions, and effectively improving the practicality and adaptability of the measurement system; wherein, by arranging eight measuring elements in the six-component strain balance, it is possible to Comprehensively capturing the stress conditions of the rotor nacelle to be tested in different directions ensures the comprehensiveness and accuracy of the measurement data, helps to more accurately measure the aerodynamic characteristics of the rotor nacelle under different working conditions, and provides strong support for the design optimization, performance improvement and troubleshooting of tilt-rotor UAVs; in addition, installing the rotor nacelle to be tested on the top side of the nacelle support can support the adjustment and control of the tilt angle, total pitch or cyclic pitch of the rotor nacelle to be tested, so as to simulate various postures and states of the rotor nacelle in actual flight, thereby meeting the test requirements under different working conditions, while ensuring the stability and safety of the rotor nacelle to be tested during the measurement process. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A schematic diagram of the structure of the tilt-rotor UAV rotor nacelle aerodynamic force measurement system provided in Example 1;

[0046] Figure 2 Schematic diagram of the installation structure of the rotor nacelle to be tested in Example 1;

[0047] Figure 3 Schematic diagram of the structure of the six-component strain balance in Example 1;

[0048] Figure 4 Schematic diagram of the full-bridge circuit module in the six-component strain balance in Example 1;

[0049] Figure 5 Flow chart of the method for measuring aerodynamic force of the rotor nacelle of a tilt-rotor UAV provided in Example 2.

[0050] Among them, 1 is a main support stand, 2 is an adapter stand, 3 is a six-component strain balance, 4 is a nacelle support, 5 is a rotor nacelle to be measured; 31 is a balance body, 32 is a first measuring element, 33 is a second measuring element, 34 is a third measuring element, 35 is a fourth measuring element, 36 is a fifth measuring element, 37 is a sixth measuring element, 38 is a seventh measuring element, 39 is an eighth measuring element; 301 is a first strain gauge, 302 is a second strain gauge, 303 is a third strain gauge, 304 is a fourth strain gauge; 51 is a tilt-steer servo, 52 is a propeller hub, 53 is a rotor, 54 is a rotor shaft, 55 is a variable pitch servo, and 56 is a power motor. DETAILED DESCRIPTION

[0051] In order to make the technical problems, technical solutions and beneficial effects solved by this application clearer, the technical solutions in the embodiments of this application will be described clearly and completely in combination with the drawings in the embodiments of this application; obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] Example 1

[0053] As attached Figure 1-4 As shown, this embodiment 1 provides a tilt-rotor UAV rotor nacelle aerodynamic measurement system, including a main support stand 1, a transfer stand 2, a six-component strain balance 3, a nacelle support 4 and a data acquisition and processing module.

[0054] The main support bench 1 is vertically fixed on the ground or the test bench, and the adapter bench 2 is installed on the top of the support bench 1; wherein, the main support bench 1 and the adapter bench 2 are combined up and down to form a test bench; the test bench is used as a load-bearing support frame for the six-component strain balance 3, the nacelle support 4 and the rotor nacelle 5 to be tested; preferably, the main support bench 1 and the adapter bench 2 are both welded with steel structures, the main support bench 1 is fixedly connected to the ground or the test bench by anchor bolts, and the adapter bench 2 is connected to the main support bench 1 by bolts.

[0055] The six-component strain balance 3 is arranged at the top of the test bench, and the nacelle support 4 is arranged at the top of the six-component strain balance 3; wherein, the six-component strain balance 3 is installed on the top of the adapter bench 2 by screws, and the nacelle support 4 is installed on the top of the six-component strain balance 3 by screws.

[0056] Specifically, the six-component strain balance 3 includes a balance body 31 and eight measuring elements; the balance body 31 is installed on the top of the adapter stand 2 by screws, and the nacelle support 4 is installed at the top center of the balance body 31; wherein, the bottom of the balance body 31 is connected to the top of the adapter stand 2 by screws, and the bottom of the nacelle support 4 is connected to the top center of the balance body 31 by screws; the eight measuring elements are evenly distributed around the balance body 31, and the eight measuring elements are connected to the data acquisition and processing module; wherein four of the measuring elements are respectively arranged at the four corners of the balance body 31, and the remaining four measuring elements are respectively arranged at the four sides of the balance body 31; preferably, the eight measuring elements have the same structure, and all adopt a full-bridge circuit module; wherein the full-bridge circuit module is a Wheatstone full-bridge circuit formed by connecting four strain gauges.

[0057] It should be noted that the eight measuring elements specifically include a first measuring element 32, a second measuring element 33, a third measuring element 34, a fourth measuring element 35, a fifth measuring element 36, a sixth measuring element 37, a seventh measuring element 38 and an eighth measuring element 39; the first measuring element 32, the second measuring element 33, the third measuring element 34, the fourth measuring element 35, the fifth measuring element 36, the sixth measuring element 37, the seventh measuring element 38 and the eighth measuring element 39 are all connected to the data acquisition and processing module through cables.

[0058] The first measuring element 32 , the second measuring element 33 , the third measuring element 34 and the fourth measuring element are distributed at the four corners of the balance body 31 ; the fourth measuring element 35 , the fifth measuring element 36 , the sixth measuring element 37 , the seventh measuring element 38 and the eighth measuring element 39 are respectively arranged at the four sides of the balance body 31 .

[0059] Specifically, along the counterclockwise direction of the horizontal plane where the balance body 31 is located, the first measuring element 32 is located at a first corner of the balance body 31, the second measuring element 33 is located at a second corner of the balance body 31, the third measuring element 34 is located at a fourth corner of the balance body 31, and the fourth measuring element 35 is located at a third corner of the balance body 31; that is, the first measuring element 32 and the fourth measuring element 35 are arranged along one diagonal line of the balance body 31, and the second measuring element 33 and the third measuring element 34 are arranged along another diagonal line of the balance body 31.

[0060] Along the counterclockwise direction of the horizontal plane where the balance body 31 is located, the eighth measuring element 39 is located at the first side of the balance body 31, the fifth measuring element 36 is located at the second side of the balance body 31, the seventh measuring element 38 is located at the third side of the balance body 31, and the sixth measuring element 37 is located at the fourth side of the balance body 31; that is, the eighth measuring element 39 is arranged between the first measuring element 32 and the second measuring element 33, the fifth measuring element 36 is arranged between the second measuring element 33 and the fourth measuring element 35, the seventh measuring element 38 is arranged between the fourth measuring element 35 and the fourth measuring element 34, and the sixth measuring element 37 is arranged between the third measuring element 34 and the first measuring element 32.

[0061] The nacelle support 4 includes a base plate, an end plate and two connecting side plates; the base plate is horizontally fixed at the top center of the balance body 31, and the base plate and the top of the balance body 31 are connected by screws; the end plate is vertically fixed to one side of the upper surface of the base plate, and the end plate is used as a mounting plate for the rotor nacelle 5 to be tested; the two connecting side plates are vertically symmetrically arranged on the upper surface of the base plate, and are used to fix the base plate to the end plate; wherein one end of the connecting side plate is vertically fixed to the base plate, and the other end of the connecting side plate is vertically fixed to the end plate.

[0062] The rotor nacelle 5 to be tested is a rotor nacelle system in a tilt-rotor UAV, and has the functions of rotor collective pitch variation, rotor cyclic pitch variation and nacelle tilt; the rotor nacelle 5 to be tested includes a tilt-rotor servo 51, a hub 52, a rotor 53, a rotor shaft 54, a pitch-variable servo 55 and a power motor 56; wherein the rotary servo 51 is arranged above the base plate and mounted on the end plate; it should be noted that other structural features of the rotor nacelle 5 to be tested are the same as those of the rotor nacelle system in the existing tilt-rotor UAV, and will not be repeated here.

[0063] In this embodiment 1, the eight measuring elements in the six-component strain balance 3 are used to sense the stress changes acting on the balance body 31 of the rotor nacelle 5 to be tested under a preset tilt angle, collective pitch or cyclic pitch change condition and output them in the form of electrical signals to obtain voltage measurement data; the data acquisition and processing module is used to obtain the voltage measurement data, and calculate the aerodynamic parameters of the rotor nacelle 5 to be tested under the preset tilt angle, collective pitch or shaft pitch change condition according to the voltage measurement data; wherein the aerodynamic parameters of the rotor nacelle 5 to be tested under the preset tilt angle, collective pitch or shaft pitch change condition include three force components and three torque components of the rotor nacelle 5 to be tested under the preset tilt angle, collective pitch or shaft pitch change condition.

[0064] Specifically, the three force components of the rotor nacelle 5 to be tested under the preset tilt angle, total pitch or shaft pitch change conditions include: x Aerodynamic force , y Aerodynamic force and z Aerodynamic force The three torque components of the rotor nacelle 5 to be tested under the preset tilt angle, total pitch or shaft pitch change conditions include x Axis aerodynamic torque , around y Axis aerodynamic torque And around z Axis aerodynamic torque It should be noted that x Towards, y Towards, z Towards, x axis, y Axis and z Axes follow pre-built measurement axes xyz Define; wherein, define the axis of the output shaft of the tilting servo 51 in the rotor nacelle 5 to be measured as the pre-constructed measurement coordinate system xyz of x Axis, defines the normal direction of the top of the balance body 31 as a pre-constructed measurement coordinate system xyz of z Axis, defines the centering of the balance body 31 as a pre-built measurement coordinate system xyz The pre-constructed measurement coordinate system is determined according to the right-hand rule. xyz of y axis.

[0065] It should be noted that, in order to test the rotor nacelle 5 to be tested under a preset tilt angle, collective pitch or shaft pitch change condition, the rotor nacelle 5 to be tested is also equipped with a controller, and the controller is connected to the tilt servo 51, the pitch servo 55 and the power motor 56 respectively through cables to achieve adjustment and control of the tilt angle, rotation speed, collective pitch and cyclic pitch change of the rotor nacelle 5 to be tested.

[0066] How to use and working principle:

[0067] The tilt-rotor UAV rotor nacelle aerodynamic force measurement system described in Example 1 is used as follows:

[0068] Step 1: Connect and install the main support stand 1, the transfer stand 2, the six-component strain balance 3, the nacelle support 4 and the rotor nacelle to be measured 5 in sequence.

[0069] Step 2: Connect the tilting servo 51, the variable pitch servo 55 and the power motor 56 in the rotor nacelle 5 to be tested to the controller through cables, respectively, and confirm that they are in normal state.

[0070] Step 3: Connect the eight measuring elements in the six-component strain balance 3 to the data acquisition and processing module through cables, and confirm that they are in normal state.

[0071] Step 4: Use the controller to regulate the tilting servo 51 so that the rotor nacelle 5 to be tested is at a preset tilting angle.

[0072] Step 5: When the rotor nacelle 5 to be measured is at a preset tilt angle, the voltage measurement data output by the eight measuring elements in the six-component strain balance 3 are obtained to obtain an initial output voltage reading; it should be noted that the initial output voltage reading is caused by the self-weight of the measurement system.

[0073] Step 6: Use the controller to regulate the power motor 56, and drive the rotor shaft 54, the hub 52 and the rotor 53 to rotate through the power motor 56 and reach the rated speed; that is, make the rotor nacelle 5 to be tested in the rated speed operation state.

[0074] Step 7: Utilize the controller to regulate the variable pitch servo 55 , and control the variable pitch servo 55 so that the rotor nacelle 5 to be tested is in a preset collective pitch or cyclic pitch state.

[0075] Step 8. When the rotor nacelle 5 to be measured is in a preset collective pitch or cyclic pitch state, the voltage measurement data output by the eight measuring elements in the six-component strain balance 3 is obtained to obtain the final output voltage reading; it should be noted that the final output voltage reading is caused by the weight of the measurement system itself and the aerodynamic force of the rotor nacelle 5 to be measured.

[0076] Step 9: Use a data acquisition and processing module to collect and process the initial output voltage reading and the final output voltage reading to obtain aerodynamic parameters of the rotor nacelle 5 to be tested under a preset tilt angle, collective pitch or cyclic pitch variation conditions.

[0077] The tilt-rotor UAV rotor nacelle aerodynamic force measurement system described in Example 1 uses a six-component strain balance 3 to sense the voltage measurement data of the rotor nacelle 5 to be measured under a preset tilt angle, total pitch or cyclic pitch condition; specifically, the eight measuring elements in the six-component strain balance 3 are all connected by four strain gauges to form a Wheatstone full-bridge circuit; in the Wheatstone full-bridge circuit, Indicates the bridge supply voltage, Indicates the voltage measurement data output by the measuring element, as shown in the attached Figure 4As shown; when the six-component strain balance 3 is not subjected to external force, the Wheatstone full-bridge circuit is in a balanced state, and the output voltage measurement data is zero at this time; when the six-component strain balance 3 is subjected to external force, the strain gauge in the measuring element is deformed after being subjected to the load, so that the resistance value of the strain gauge changes, and the Wheatstone full-bridge circuit loses its balanced state at this time, thereby generating non-zero voltage measurement data; the aerodynamic parameters of the rotor nacelle to be measured under the preset tilt angle, total pitch or cyclic pitch variation conditions are calculated based on the acquired voltage measurement data, so as to realize the accurate measurement of the aerodynamic parameters of the rotor nacelle to be measured under different working conditions.

[0078] Example 2

[0079] This embodiment 2 provides a tilt-rotor UAV rotor nacelle aerodynamic measurement method, using the tilt-rotor UAV rotor nacelle aerodynamic measurement system described in the above embodiment 1; as shown in the attached Figure 5 As shown, the rotor nacelle aerodynamic force measurement method comprises the following steps:

[0080] Step 1: statically calibrate the six-component strain balance 3. The six-component strain balance 3 is statically calibrated using a preset static calibration method to obtain the main coefficient matrix of the six-component strain balance 3. , the coefficient matrix of the first-order interference term of the six-component strain balance 3 And the quadratic interference coefficient matrix of the six-component strain balance 3 .

[0081] Specifically, the process of statically calibrating the six-component strain gauge balance 3 includes the following steps:

[0082] The six-component strain balance 3 is installed on the preset calibration device and measured according to the pre-built measurement coordinate system. xyz Apply a static load to the six-component strain balance 3; record the applied static load and the output signal of the six-component strain balance 3; calculate the main coefficient matrix of the six-component strain balance 3 according to the change relationship between the recorded applied static load and the output signal of the six-component strain balance 3 , the coefficient matrix of the first-order interference term of the six-component strain balance 3 And the quadratic interference coefficient matrix of the six-component strain balance 3 .

[0083] Step 2: adjusting and controlling the tilt angle of the rotor nacelle 5 to be tested by the tilt servo 51 so that the rotor nacelle 5 to be tested is at a preset tilt angle.

[0084] Step 3: When the rotor nacelle 5 to be measured is at a preset tilt angle, the voltage measurement data output by the eight measuring elements in the six-component strain balance 3 is obtained to obtain an initial output voltage reading. The initial output voltage reading includes the initial output voltage reading of the first measuring element 32. , the initial reading of the output voltage of the second measuring element 33 , the initial reading of the output voltage of the third measuring element 34 , the initial reading of the output voltage of the fourth measuring element 35 , the initial reading of the output voltage of the fifth measuring element 36 , the initial reading of the output voltage of the sixth measuring element 37 , the initial reading of the output voltage of the seventh measuring element 38 , the initial reading of the output voltage of the eighth measuring element 39 .

[0085] Step 6: Use the controller to regulate the power motor 56, and drive the rotor shaft 54, the hub 52 and the rotor 53 to rotate through the power motor 56 and reach the rated speed; that is, make the rotor nacelle 5 to be tested in the rated speed operation state.

[0086] Step 7: Use the pitch-changing servo 55 to adjust and control the collective pitch or cyclic pitch of the rotor nacelle 5 to be tested, so that the rotor nacelle 5 to be tested is in a preset collective pitch or cyclic pitch state.

[0087] Step 8: When the rotor nacelle 5 to be measured is in a preset collective pitch or cyclic pitch state, the voltage measurement data output by the eight measuring elements in the six-component strain balance 3 is obtained to obtain the output voltage final reading. The output voltage final reading includes the output voltage final reading of the first measuring element 32. , the output voltage of the second measuring element 33 is read , the output voltage of the third measuring element 34 is not read , the output voltage of the fourth measuring element 35 is the final reading , the output voltage of the fifth measuring element 36 is not read , the output voltage of the sixth measuring element 37 is read , the output voltage final reading of the seventh measuring element 38 , the output voltage final reading of the eighth measuring element 39 .

[0088] Step 9: Calculate the aerodynamic parameters of the rotor nacelle 5 to be tested under a preset tilt angle, collective pitch or cyclic pitch condition according to the initial output voltage reading and the final output voltage reading.

[0089] Specifically, the process of calculating the aerodynamic parameters of the rotor nacelle 5 to be tested under the preset tilt angle, collective pitch or cyclic pitch condition according to the output voltage initial reading and the output voltage final reading is as follows:

[0090] Step 91, according to the output voltage initial reading and the output voltage final reading, calculate the voltage increment corresponding to the aerodynamic performance of the rotor nacelle 5 to be tested under different collective pitch or cyclic pitch conditions. Specifically, the steps are as follows:

[0091] Step 911: Calculate the voltage increments of the eight measuring elements in the six-component strain balance 3 according to the initial output voltage reading and the final output voltage reading; wherein the voltage increments of the eight measuring elements in the six-component strain balance 3 are caused by the aerodynamic force of the rotor nacelle 5 to be measured under different collective pitch or cyclic pitch variation conditions; wherein the calculation process of the voltage increments of the eight measuring elements in the six-component strain balance 3 is as follows:

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100] in, is the difference between the final output voltage reading and the initial output voltage reading of the first measuring element, i.e., the voltage increment of the first measuring element 32; is the difference between the final output voltage reading and the initial output voltage reading of the second measuring element, i.e., the voltage increment of the second measuring element 33; is the difference between the final output voltage reading and the initial output voltage reading of the third measuring element, i.e., the voltage increment of the third measuring element 34; is the difference between the final output voltage reading and the initial output voltage reading of the fourth measuring element, that is, the voltage increment of the fourth measuring element 35; is the difference between the final output voltage reading and the initial output voltage reading of the fifth measuring element, i.e., the voltage increment of the fifth measuring element 36; is the difference between the final output voltage reading and the initial output voltage reading of the sixth measuring element, i.e., the voltage increment of the sixth measuring element 37; is the difference between the final output voltage reading and the initial output voltage reading of the seventh measuring element, that is, the voltage increment of the seventh measuring element 38; It is the difference between the final output voltage reading and the initial output voltage reading of the eighth measuring element, that is, the voltage increment of the eighth measuring element 39.

[0101] Step 912: According to the balance bridge formula, the voltage increments of the eight measuring elements in the six-component strain balance 3 are converted into voltage increments corresponding to the aerodynamic performance of the rotor nacelle 5 to be measured under different collective pitch or cyclic pitch change conditions; wherein the calculation process of the voltage increment corresponding to the aerodynamic performance of the rotor nacelle 5 to be measured under different collective pitch or cyclic pitch change conditions is specifically as follows:

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108] in, for y The voltage increment corresponding to the aerodynamic force; For around z The voltage increment corresponding to the shaft aerodynamic torque; For around x The voltage increment corresponding to the shaft aerodynamic torque; for x The voltage increment corresponding to the aerodynamic force; for z The voltage increment corresponding to the aerodynamic force; For around y The voltage increment corresponding to the shaft aerodynamic torque.

[0109] Step 92: Calculate the aerodynamic parameters of the rotor nacelle 5 under a preset tilt angle, collective pitch or cyclic pitch variation condition according to the voltage increment corresponding to the aerodynamic performance of the rotor nacelle 5 under different collective pitch or cyclic pitch variation conditions; wherein the calculation formula of the aerodynamic parameters of the rotor nacelle 5 under a preset tilt angle, collective pitch or cyclic pitch variation condition is specifically:

[0110]

[0111] in, is the six-component aerodynamic matrix of the rotor nacelle 5 to be measured relative to the six-component strain balance 3; is the principal coefficient matrix of the six-component strain balance 3; is the coefficient matrix of the first-order interference term of the six-component strain balance 3; is the first-order interference matrix of the six-component strain balance 3; is the coefficient matrix of quadratic interference term of six-component strain balance 3; is the quadratic interference matrix of the six-component strain balance 3.

[0112] Specifically:

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120] in, for y Aerodynamic force; For around z Axis aerodynamic torque; For around x Axis aerodynamic torque; for x Aerodynamic force; for z Aerodynamic force; For around y Axis aerodynamic torque.

[0121] It should be noted that in the quadratic interference matrix of the six-component strain balance 3, express y Aerodynamic force ,Right now; ;use Indicates winding z The aerodynamic torque of the shaft is ;use Indicates winding x The aerodynamic torque of the shaft is ;use express x Aerodynamic force, i.e. ;use express z Aerodynamic force, i.e. ;use Indicates winding y The aerodynamic torque of the shaft is .

[0122] It should be noted that the calculation formula for the aerodynamic parameters of the rotor nacelle 5 to be tested under the preset tilt angle, collective pitch or cyclic pitch variation conditions is in a hidden format. By solving the calculation formula for the aerodynamic parameters of the rotor nacelle 5 to be tested under the preset tilt angle, collective pitch or cyclic pitch variation conditions in an iterative calculation manner, the aerodynamic parameters of the rotor nacelle 5 to be tested under the preset tilt angle, collective pitch or cyclic pitch variation conditions can be obtained.

[0123] The rotor nacelle aerodynamic force measurement system and method described in the present invention can comprehensively capture the force conditions of the rotor nacelle to be measured in different directions by arranging eight measuring elements in a six-component strain balance, thereby ensuring the comprehensiveness and accuracy of the measurement data; the six-component strain balance is used to sense the voltage measurement data of the rotor nacelle to be measured under a preset tilt angle, total pitch or cyclic pitch change working condition, and the aerodynamic force parameters of the rotor nacelle to be measured under the preset tilt angle, total pitch or cyclic pitch change working condition are calculated based on the acquired voltage measurement data, thereby achieving accurate measurement of the aerodynamic force parameters of the rotor nacelle to be measured under different working conditions, effectively improving the practicability and adaptability of the measurement system, and effectively solving the problem that the traditional rotor test bench cannot change the nacelle tilt angle and the rotor total pitch and cyclic pitch change when measuring the rotor aerodynamic force.

[0124] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention.

Claims

1. A tilt-rotor UAV rotor nacelle aerodynamic measurement system, characterized in that: The invention comprises a test bench, a six-component strain balance (3), a nacelle support (4), and a data acquisition and processing module; the six-component strain balance (3) is arranged at the top of the test bench, the nacelle support (4) is arranged at the top of the six-component strain balance (3), and the rotor nacelle (5) to be tested is installed on the side of the top of the nacelle support (4); The six-component strain balance (3) comprises a balance body (31) and eight measuring elements; the balance body (31) is arranged at the top of the test bench, and the nacelle support (4) is installed at the top center of the balance body (31); four of the measuring elements are respectively arranged at the four corners of the balance body (31), and the remaining four measuring elements are respectively arranged at the four sides of the balance body (31); the eight measuring elements are connected to the data acquisition and processing module; The measuring element is used to sense the stress change acting on the balance body (31) of the rotor nacelle (5) to be measured under a preset tilt angle, collective pitch or cyclic pitch change condition and output it in the form of an electrical signal to obtain voltage measurement data; the data acquisition and processing module is used to obtain and calculate the aerodynamic parameters of the rotor nacelle (5) to be measured under the preset tilt angle, collective pitch or cyclic pitch change condition based on the voltage measurement data.

2. The tilt-rotor UAV rotor nacelle aerodynamic force measurement system according to claim 1, characterized in that: The eight measuring elements have the same structure and all adopt a full-bridge circuit module; wherein the full-bridge circuit module is a Wheatstone full-bridge circuit formed by connecting four strain gauges.

3. The tilt-rotor UAV rotor nacelle aerodynamic force measurement system according to claim 1, characterized in that: The aerodynamic parameters of the rotor nacelle (5) to be tested under a preset tilt angle, collective pitch or cyclic pitch condition are specifically: in, is the six-component aerodynamic matrix of the rotor nacelle (5) to be measured, centered relative to the six-component strain balance (3); is the principal coefficient matrix of the six-component strain balance (3); is the coefficient matrix of the first-order interference term of the six-component strain balance (3); is the first-order interference matrix of the six-component strain balance (3); is the coefficient matrix of the quadratic interference term of the six-component strain balance (3); is the quadratic interference matrix of the six-component strain balance (3); for y The voltage increment corresponding to the aerodynamic force; For around z The voltage increment corresponding to the shaft aerodynamic torque; For around x The voltage increment corresponding to the shaft aerodynamic torque; for x The voltage increment corresponding to the aerodynamic force; for z The voltage increment corresponding to the aerodynamic force; For around y The voltage increment corresponding to the shaft aerodynamic torque; in, y Voltage increment corresponding to the aerodynamic force , around z Voltage increment corresponding to the shaft aerodynamic torque , around x Voltage increment corresponding to the shaft aerodynamic torque , x Voltage increment corresponding to the aerodynamic force , z Voltage increment corresponding to the aerodynamic force And around y Voltage increment corresponding to the shaft aerodynamic torque The voltage measurement data are respectively used for calculation.

4. The tilt-rotor UAV rotor nacelle aerodynamic force measurement system according to claim 1, characterized in that: The test bench comprises a main support bench (1) and a transfer bench (2); the main support bench (1) is vertically fixed on the ground or a test bench surface, the transfer bench (2) is installed on the top of the main support bench (1), and the six-component strain balance (3) is installed on the top of the transfer bench (2).

5. A method for measuring the aerodynamic force of a tilt-rotor UAV rotor nacelle, characterized in that: Utilizing the tilt-rotor UAV rotor nacelle aerodynamic force measurement system as described in any one of claims 1 to 4; The tilt-rotor UAV rotor nacelle aerodynamic measurement method comprises: Adjusting and controlling the tilt angle of the rotor nacelle (5) to be tested so that the rotor nacelle (5) to be tested is at a preset tilt angle; When the rotor nacelle (5) to be measured is at a preset tilt angle, obtaining voltage measurement data output by eight measuring elements in the six-component strain balance (3) to obtain an initial output voltage reading; Adjusting and controlling the collective pitch or cyclic pitch variation of the rotor nacelle (5) to be tested so that the rotor nacelle (5) to be tested is in a preset collective pitch or cyclic pitch variation state; When the rotor nacelle (5) to be measured is in a preset collective pitch or cyclic pitch change state, obtaining voltage measurement data output by eight measuring elements in the six-component strain balance (3) to obtain a final output voltage reading; The aerodynamic parameters of the rotor nacelle (5) to be tested under a preset tilt angle, collective pitch or cyclic pitch condition are calculated based on the output voltage initial reading and the output voltage final reading.

6. A tilt-rotor UAV rotor nacelle aerodynamic measurement method according to claim 5, characterized in that: The process of calculating the aerodynamic parameters of the rotor nacelle (5) to be tested under a preset tilt angle, collective pitch or cyclic pitch condition according to the output voltage initial reading and the output voltage final reading comprises the following steps: According to the output voltage initial reading and the output voltage final reading, a voltage increment corresponding to the aerodynamic performance of the rotor nacelle (5) to be tested under different collective pitch or cyclic pitch variation conditions is calculated; The aerodynamic parameters of the rotor nacelle (5) to be tested under a preset tilt angle, collective pitch or cyclic pitch condition are calculated based on the voltage increment corresponding to the aerodynamic performance of the rotor nacelle (5) to be tested under different collective pitch or cyclic pitch condition.

7. A method for measuring aerodynamic force of a tilt-rotor UAV rotor nacelle according to claim 6, characterized in that: The voltage increment corresponding to the aerodynamic performance of the rotor nacelle (5) to be tested under different collective pitch or cyclic pitch variation conditions is specifically: in, for y The voltage increment corresponding to the aerodynamic force; For around z The voltage increment corresponding to the shaft aerodynamic torque; For around x The voltage increment corresponding to the shaft aerodynamic torque; for x The voltage increment corresponding to the aerodynamic force; for z The voltage increment corresponding to the aerodynamic force; For around y The voltage increment corresponding to the shaft aerodynamic torque; It is the difference between the final output voltage reading and the initial output voltage reading of the first measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the second measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the third measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the fourth measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the fifth measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the sixth measuring element; is the difference between the final output voltage reading and the initial output voltage reading of the seventh measuring element; It is the difference between the final output voltage reading and the initial output voltage reading of the eighth measuring element.

8. The method for measuring aerodynamic force of a tilt-rotor UAV rotor nacelle according to claim 7, characterized in that: The process of calculating the aerodynamic parameters of the rotor nacelle (5) to be tested under a preset tilt angle, collective pitch or cyclic pitch condition according to the voltage increment corresponding to the aerodynamic performance of the rotor nacelle (5) to be tested under different collective pitch or cyclic pitch condition is as follows: in, is the six-component aerodynamic matrix of the rotor nacelle (5) to be measured, centered relative to the six-component strain balance (3); is the principal coefficient matrix of the six-component strain balance (3); is the coefficient matrix of the first-order interference term of the six-component strain balance (3); is the first-order interference matrix of the six-component strain balance (3); is the coefficient matrix of the quadratic interference term of the six-component strain balance (3); is the quadratic interference matrix of the six-component strain balance (3); for y The voltage increment corresponding to the aerodynamic force; For around z The voltage increment corresponding to the shaft aerodynamic torque; For around x The voltage increment corresponding to the shaft aerodynamic torque; for x The voltage increment corresponding to the aerodynamic force; for z The voltage increment corresponding to the aerodynamic force; For around y The voltage increment corresponding to the shaft aerodynamic torque.

9. The method for measuring aerodynamic force of a rotor nacelle of a tilt-rotor UAV according to claim 8, characterized in that: The tilt angle of the rotor nacelle (5) to be tested is adjusted and controlled so that the rotor nacelle (5) to be tested is located before a preset tilt angle, and also includes a static calibration step; The static calibration step is specifically as follows: The six-component strain balance (3) is calibrated statically to obtain the principal coefficient matrix of the six-component strain balance (3): , the first-order interference coefficient matrix of the six-component strain balance (3) And the quadratic interference coefficient matrix of the six-component strain balance (3) .

10. The method for measuring aerodynamic force of a rotor nacelle of a tilt-rotor UAV according to claim 5, characterized in that: When the rotor nacelle (5) to be tested is in a preset collective pitch or cyclic pitch change state, the rotor nacelle (5) to be tested is in a rated speed operation state.

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