An Unmanned Aerial Vehicle Gravity Center Measurement and Thrust Line Adjustment Device and Method

Abstract

The present invention discloses a device for measuring the center of gravity and adjusting the thrust line of an unmanned aerial vehicle, which includes a bearing platform. A support assembly for the unmanned aerial vehicle is provided on the bearing platform, and a variety of measuring sensors are cooperatively installed. The present invention also discloses a method for measuring the center of gravity and adjusting the thrust line of an unmanned aerial vehicle. Through the above support assembly and measuring sensors, the actual center of gravity position of the unmanned aerial vehicle is obtained, and then the angle that the booster rocket needs to be adjusted is obtained, which is convenient for adjusting the thrust line of the unmanned aerial vehicle. The beneficial effects of the present invention are as follows: The installation and positioning accuracy of the unmanned aerial vehicle is higher, which is beneficial to reducing the deviation of the center of gravity measurement caused by the error of the unmanned aerial vehicle's feet, beneficial to improving the measurement and calculation accuracy, and effectively reducing the launch risk caused by inaccurate measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicle (UAV) launching, in particular to a device and method for measuring the center of gravity of a UAV and adjusting the thrust line. Background Art

[0002] At present, UAVs have been widely used in both military and civilian fields and play an increasingly important role. Rocket boost is a commonly used launching method for UAVs. Before launching, it is necessary to measure the actual center of gravity of the UAV and adjust the thrust line so that the boost direction is consistent with the actual center of gravity of the UAV to ensure the safe launch of the UAV.

[0003] Traditional methods for measuring the center of gravity of UAVs mostly use the UAV's own feet as the positioning reference, and the support of the measuring equipment is mostly in a completely fixed manner. Due to deformation and position errors during the manufacturing process of the UAV's feet, the support of the UAV's feet and the measuring equipment cannot be accurately installed and positioned, resulting in inaccurate calculated center of gravity positions. The resulting thrust line deviation may cause launch risks. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a device and method for measuring the center of gravity of a UAV and adjusting the thrust line.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A device for measuring the center of gravity of a UAV and adjusting the thrust line includes a bearing platform. The front part of the bearing platform is relatively provided with first support frames, and the rear part of the bearing platform is provided with a second support frame. A linear sliding guide is provided on the first support frames. A lead screw mounting seat is slidably mounted on the linear sliding guide. The lower parts of the two lead screw mounting seats are respectively provided with a first X-direction distance measuring sensor and a second X-direction distance measuring sensor. A first lifting lead screw is provided on the lead screw mounting seat. The upper movable ends of the two first lifting lead screws are respectively provided with a first weighing sensor and a second weighing sensor. Leg fixing seats are provided on both the first weighing sensor and the second weighing sensor. A second lifting lead screw is installed on the second support frame. Distance measuring reference plates adapted to the first X-direction distance measuring sensor and the second X-direction distance measuring sensor are provided on both sides of the second support frame. The upper end of the second lifting lead screw is provided with a third weighing sensor. The upper end of the third weighing sensor is provided with a simulated tooling ball seat. A boost rocket simulation tooling is provided on the simulated tooling ball seat. An inclination sensor is provided on the boost rocket simulation tooling.

[0007] The X-direction ranging sensor measures the actual distance in the horizontal direction between the front and rear supports in real time; the booster rocket simulation tooling is installed on the UAV instead of the booster rocket and is installed in the simulation tooling ball seat to fix the UAV; the inclination sensor measures the inclination angle of the UAV in real time during measurement and adjustment.

[0008] Further, the end face of the ranging reference plate coincides with the axis of the second lifting screw. One of the ranging reference plates is perpendicular to the first X-direction ranging sensor, and the other ranging reference plate is perpendicular to the second X-direction ranging sensor.

[0009] Further, a linear through hole adapted to the first lifting screw is provided in the middle of the linear sliding guide.

[0010] Further, a third support frame is provided behind the second support frame on the bearing platform. A third lifting screw is provided at the upper end of the third support frame. A rubber base is provided at the upper end of the third lifting screw. An arc surface for supporting the UAV is provided at the upper end of the rubber base.

[0011] The rubber base is used to protect the UAV from being bumped and to lift the aircraft when adjusting the thrust line.

[0012] Further, a thrust line projection display board is provided behind the third support frame on the bearing platform.

[0013] The thrust line projection display board is used to check whether the adjustment of the thrust line reaches the desired position.

[0014] Further, roller feet are installed at the bottom of the bearing platform. The roller feet are used for the movement and leveling of the device.

[0015] A method for measuring the center of gravity and adjusting the thrust line of a UAV includes the following steps:

[0016] Step 1: Install the booster rocket simulation tooling on the UAV;

[0017] Step 2: Lift and place the UAV onto the measuring device. The booster rocket simulation tooling installed on the UAV is placed in the simulation tooling ball seat. The two front feet of the UAV are respectively placed on the two leg fixing seats at the front end of the device. Under the action of the gravity of the UAV, the first lifting screws under the two leg fixing seats respectively generate displacements along their respective linear sliding guides 5. After the adjustment is completed, three-point support for the UAV is formed.

[0018] Step 3: Use the first lifting lead screw and the second lifting lead screw to adjust the UAV to a horizontal state. Taking the simulated tooling ball seat as the coordinate origin, establish a coordinate system XYZ, measure the values of the first weighing sensor, the second weighing sensor, the third weighing sensor, the first X-direction distance measuring sensor, and the second X-direction distance measuring sensor, and calculate the centroid positions of the UAV in the X direction and the Y direction;

[0019] Step 4: Use the second lifting lead screw to lower the height of the aircraft tail. At the same time, the first lifting lead screws at the two front legs will also move in the direction close to the tail along the linear sliding guide 5 under the push of the UAV legs. After the displacement is in place, measure the values of the first weighing sensor, the second weighing sensor, the third weighing sensor, the first X-direction distance measuring sensor, the second X-direction distance measuring sensor, and the inclination sensor, and calculate the centroid position of the UAV in the Z direction;

[0020] Step 5: According to the actual centroid position of the UAV in the coordinate system, obtain the angle that the booster rocket needs to adjust, and adjust the thrust line to make the thrust line match the actual centroid.

[0021] The present invention has the following advantages:

[0022] The installation and positioning accuracy of the UAV is higher, which is beneficial to reducing the centroid measurement deviation caused by the UAV leg error, beneficial to improving the measurement and calculation accuracy, and effectively reducing the launch risk caused by inaccurate measurement. Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of the present invention.

[0024] Figure 2 It is a top view of the XY coordinates of the actual centroid in the horizontal state of the UAV.

[0025] Figure 3 It is a front view of the Z coordinate of the actual centroid in the inclined state of the UAV.

[0026] Figure 4 It is a schematic diagram of the inclined state of the UAV.

[0027] In the figure, 1 - bearing platform, 2 - first support frame, 3 - second support frame, 4 - linear sliding guide rail, 5 - lead screw mounting base, 6 - first X-direction distance measuring sensor, 7 - second X-direction distance measuring sensor, 8 - first lifting lead screw, 9 - first weighing sensor, 10 - second weighing sensor, 11 - leg fixing base, 12 - second lifting lead screw, 13 - distance measuring reference plate, 14 - third weighing sensor, 15 - simulated tooling ball seat, 16 - simulated tooling of booster rocket, 17 - linear through hole, 18 - third support frame, 19 - third lifting lead screw, 20 - rubber base, 21 - thrust line projection display board, 22 - roller foot, 23 - actual center of gravity position of the UAV, 24 - expected thrust line, 25 - initial thrust line of the simulated tooling of booster rocket. Detailed implementation manners

[0028] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0031] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0032] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0033] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "install", "connect", and "couple" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. 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.

[0034] Refer to Figures 1-4 As shown, an embodiment of the present invention is:

[0035] An unmanned aerial vehicle (UAV) center-of-gravity measurement and thrust-line adjustment device, comprising a bearing platform 1. First support frames 2 are oppositely arranged at the front part of the bearing platform 1. A second support frame 3 is arranged at the rear part of the bearing platform 1. A linear sliding guide rail 4 is arranged on the first support frame 2. A lead screw mounting seat 5 is slidably mounted on the linear sliding guide rail 4. A first X-direction distance measuring sensor 6 and a second X-direction distance measuring sensor 7 are respectively mounted on the lower parts of the two lead screw mounting seats 5. A first lifting lead screw 8 is arranged on the lead screw mounting seat 5. First weighing sensors 9 and second weighing sensors 10 are respectively arranged at the upper movable ends of the two first lifting lead screws 8. Leg fixing seats 11 are arranged on both the first weighing sensor 9 and the second weighing sensor 10. A second lifting lead screw 12 is mounted on the second support frame 3. Distance measuring reference plates 13 adapted to the first X-direction distance measuring sensor 6 and the second X-direction distance measuring sensor 7 are arranged on both sides of the second support frame 3. A third weighing sensor 14 is arranged at the upper end of the second lifting lead screw 12. An analog tooling ball seat 15 is arranged at the upper end of the third weighing sensor 14. A booster rocket simulation tooling 16 is arranged on the analog tooling ball seat 15. An inclination sensor is arranged on the booster rocket simulation tooling 16.

[0036] The end face of the ranging reference plate 13 coincides with the axis of the second lifting lead screw 12. One of the ranging reference plates 13 is perpendicular to the first X-direction ranging sensor 6, and the other ranging reference plate 13 is perpendicular to the second X-direction ranging sensor 7.

[0037] A linear through hole 17 adapted to the first lifting lead screw 8 is provided in the middle of the linear sliding guide 4.

[0038] A third support frame 18 is provided behind the second support frame 3 on the bearing platform 1. A third lifting lead screw 19 is provided at the upper end of the third support frame 18. A rubber base 20 is provided at the upper end of the third lifting lead screw 19. An arc surface for supporting the unmanned aerial vehicle is provided at the upper end of the rubber base 20.

[0039] A thrust line projection display board 21 is provided behind the third support frame 18 on the bearing platform 1.

[0040] Roller feet 22 are installed at the bottom of the bearing platform 1.

[0041] A method for measuring the center of gravity and adjusting the thrust line of an unmanned aerial vehicle includes the above device and the following steps:

[0042] Step 1: Install the booster rocket simulation tooling 16 on the unmanned aerial vehicle.

[0043] Step 2: Hoist and place the unmanned aerial vehicle on the measuring device. The booster rocket simulation tooling 16 installed on the unmanned aerial vehicle is placed in the simulation tooling ball seat 15. The two front feet of the unmanned aerial vehicle are respectively placed on the two leg fixing seats 11 at the front end of the device. Under the action of the gravity of the unmanned aerial vehicle, the first lifting lead screws 8 under the two leg fixing seats 11 respectively generate displacements along their respective linear sliding guides 5. After the adjustment is completed, three-point support for the unmanned aerial vehicle is formed.

[0044] Step 3: Use the first lifting lead screw 8 and the second lifting lead screw 12 to adjust the unmanned aerial vehicle to a horizontal state. Taking the simulation tooling ball seat 15 as the coordinate origin, establish a coordinate system XYZ. Measure the values of the first weighing sensor 9, the second weighing sensor 10, the third weighing sensor 14, the first X-direction ranging sensor 6, and the second X-direction ranging sensor 7, and calculate the center of gravity positions of the unmanned aerial vehicle in the X direction and the Y direction.

[0045] Specifically, taking Figure 2 the top view of the XY coordinates of the actual center of gravity of the unmanned aerial vehicle in the horizontal state as shown, it is set that in the horizontal state of the unmanned aerial vehicle, the readings of the first weighing sensor 9, the second weighing sensor 10, and the third weighing sensor 14 are respectively P 1 、P 2 、P 3; Set the measurement center coordinates of the first X-direction distance measuring sensor 6 and the second X-direction distance measuring sensor 7 to be (a 1 , -b, 0) and (a 2 , b, 0) respectively. The simulation tooling ball seat 15 is the coordinate origin with coordinates (0, 0, 0). Calculate the center of gravity of the UAV in the X and Y directions according to the relationship between force and moment balance. The specific calculation formulas are as follows:

[0046] X coordinate direction:

[0047]

[0048] Y coordinate direction:

[0049]

[0050] Calculate the center of gravity positions of the UAV in the X and Y directions.

[0051] Step 4: Use the second lifting lead screw 12 to lower the height of the aircraft tail. At the same time, the first lifting lead screws 8 at the two front feet will also move along the linear sliding guide 4 in the direction close to the tail under the push of the UAV feet. After the displacement is in place, measure the values of the first weighing sensor 9, the second weighing sensor 10, the third weighing sensor 14, the first X-direction distance measuring sensor 6, the second X-direction distance measuring sensor 7, and the inclination sensor, and calculate the center of gravity position of the UAV in the Z direction;

[0052] Specifically, taking the Figure 3 front view of the Z coordinate of the actual center of gravity of the UAV in the tilted state as shown, set the readings of the first weighing sensor 9, the second weighing sensor 10, and the third weighing sensor 14 to be P 1 ”, P 2 ’, P 3 ’; Set the distances measured by the first X-direction distance measuring sensor 6 and the second X-direction distance measuring sensor 7 to be a 1 ’ and a 2 ’ respectively, and the inclination sensor measures the inclination angle of the UAV as α. Calculate the center of gravity of the UAV in the Z direction according to the relationship between force and moment balance. The specific calculation formulas are as follows:

[0053]

[0054] Where: x - the center of gravity coordinate value in the x direction measured in the horizontal state.

[0055] Calculate the center of gravity position of the UAV in the Z direction.

[0056] Step Five: Based on the actual center-of-gravity position of the drone in the coordinate system, obtain the angle by which the booster rocket needs to be adjusted, and adjust the thrust line to match the actual center of gravity.

[0057] Specifically, taking Figure 4 the schematic diagram of the tilted state of the drone shown, obtain the actual center-of-gravity position 23 of the drone based on the center-of-gravity positions of the drone in the X, Y, and Z directions obtained in the previous steps. In the coordinate system, the connection line between the actual center-of-gravity position 23 of the drone and the coordinate origin is the expected thrust line 24. The measured angle β between the expected thrust line 24 and the initial thrust line 25 of the booster rocket simulation tooling is the angle by which the booster rocket needs to be adjusted.

[0058] This application uses a three-point support, and the front support can slide along the guide rail. Even if the drone's feet are deformed or there are position errors, it can be accurately installed and positioned; a coordinate system is established with the thrust position of the simulation tooling ball seat as the coordinate origin to reduce the deviation of the center-of-gravity measurement caused by the foot error; the distance and angle during the center-of-gravity measurement and thrust-line adjustment are measured and adjusted in real time to improve the calculation accuracy and effectively reduce the launch risk caused by inaccurate measurement.

[0059] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An unmanned aerial vehicle (UAV) gravity center measurement and thrust line adjustment device, characterized in that: It includes a bearing platform. At the front part of the bearing platform, first support frames are relatively arranged. At the rear part of the bearing platform, a second support frame is provided. A linear sliding guide rail is provided on the first support frame. A lead screw mounting seat is slidably installed on the linear sliding guide rail. A first X-direction distance measuring sensor and a second X-direction distance measuring sensor are respectively installed at the lower parts of the two lead screw mounting seats. A first lifting lead screw is provided on the lead screw mounting seat. The upper movable ends of the two first lifting lead screws are respectively provided with a first weighing sensor and a second weighing sensor. Leg fixing seats are provided on both the first weighing sensor and the second weighing sensor. A second lifting lead screw is installed on the second support frame. Distance measuring reference plates adapted to the first X-direction distance measuring sensor and the second X-direction distance measuring sensor are provided on both sides of the second support frame. A third weighing sensor is provided at the upper end of the second lifting lead screw. An analog tooling ball seat is provided at the upper end of the third weighing sensor. A booster rocket analog tooling is provided on the analog tooling ball seat. An inclination sensor is provided on the booster rocket analog tooling.

2. The unmanned aerial vehicle (UAV) gravity center measurement and thrust line adjustment device according to claim 1, characterized in that: The end face of the distance measuring reference plate coincides with the axis of the second lifting lead screw. One of the distance measuring reference plates is perpendicular to the first X-direction distance measuring sensor, and the other distance measuring reference plate is perpendicular to the second X-direction distance measuring sensor.

3. The unmanned aerial vehicle (UAV) gravity center measurement and thrust line adjustment device according to claim 1, characterized in that: A linear through hole adapted to the first lifting lead screw is opened in the middle of the linear sliding guide rail.

4. The unmanned aerial vehicle (UAV) gravity center measurement and thrust line adjustment device according to claim 1, characterized in that: A third support frame is provided behind the second support frame on the bearing platform. A third lifting lead screw is provided at the upper end of the third support frame. A rubber base is provided at the upper end of the third lifting lead screw. An arc surface for supporting the UAV is opened at the upper end of the rubber base.

5. The unmanned aerial vehicle (UAV) gravity center measurement and thrust line adjustment device according to claim 4, characterized in that: A thrust line projection display board is provided behind the third support frame on the bearing platform.

6. The unmanned aerial vehicle (UAV) gravity center measurement and thrust line adjustment device according to claim 1, characterized in that: Roller feet are installed at the bottom of the bearing platform.

7. An unmanned aerial vehicle (UAV) gravity center measurement and thrust line adjustment method, characterized in that: It includes the unmanned aerial vehicle (UAV) gravity center measurement and thrust line adjustment device according to any one of claims 1-6, and includes the following steps: Step 1: Install the booster rocket analog tooling on the UAV; Step 2: Lift and place the drone onto the measuring device. Place the booster rocket simulation tooling installed on the drone into the simulation tooling ball seat. Place the two front feet of the drone on the two leg fixing seats at the front end of the device. Under the action of the gravity of the drone, the first lifting screws under the two leg fixing seats respectively generate displacements along their respective linear sliding guides. After the adjustment is completed, a three-point support for the drone is formed. Step 3: Use the first lifting screw and the second lifting screw to adjust the drone to a horizontal state. Taking the simulation tooling ball seat as the coordinate origin, establish a coordinate system XYZ, measure the values of the first weighing sensor, the second weighing sensor, the third weighing sensor, the first X-direction distance measuring sensor, and the second X-direction distance measuring sensor, and calculate the center-of-gravity positions of the drone in the X direction and the Y direction. Step 4: Use the second lifting screw to lower the height of the tail of the aircraft. At the same time, the first lifting screws at the two front feet will also move along the linear sliding guide in the direction close to the tail under the push of the drone feet. After the displacement is in place, measure the values of the first weighing sensor, the second weighing sensor, the third weighing sensor, the first X-direction distance measuring sensor, the second X-direction distance measuring sensor, and the inclination sensor, and calculate the center-of-gravity position of the drone in the Z direction. Step 5: According to the actual center-of-gravity position of the drone in the coordinate system, obtain the angle that the booster rocket needs to be adjusted, and adjust the thrust line so that the thrust line matches the actual center of gravity.

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