CN-122016157-A - Centroid measurement system and method for winged aircraft

CN122016157ACN 122016157 ACN122016157 ACN 122016157ACN-122016157-A

Abstract

A centroid measuring system and method for a winged aircraft belong to the technical field of aircraft centroid measurement. The method solves the problems that the existing method is complex in operation, low in efficiency and precision and easy to influence in measurement safety. The three-dimensional adjustable electric combined measurement is realized through the front car mechanism with adjustable width and lifting height and the ground steel rail with adjustable horizontal distance between the front car mechanism and the rear car mechanism, the electric combined measurement tool is adopted to replace the traditional fixed or manual tool replacement mode, the rapid and accurate adaptation of the head support of the multi-model aircraft is realized, and the measurement method is simple and convenient to operate. The accuracy and repeatability of the two measurement postures are ensured, a reliable physical basis is provided for the subsequent mass center calculation by adopting the flexible measurement method, and the problems that the compatibility of multiple types of fixed measurement platforms is difficult, the measurement efficiency is low, the safety is poor and the measurement accuracy of the Z-direction mass center is not easy to guarantee are effectively solved. The method can be applied to the measurement of the mass center of the aircraft.

Inventors

ZHANG XIAOLIN
CHENG YILANG
HAN JUNHAO
LUO JINGLONG

Assignees

哈尔滨工业大学

Dates

Publication Date: 20260512
Application Date: 20260318

Claims (9)

1. A centroid measurement system for a winged aircraft, the system comprising in particular a front and a rear vehicle mechanism, wherein: The front vehicle mechanism comprises a tool base (1), a first upright post (2), a second upright post (3), a first screw nut pair (4), a second screw nut pair (5), a linear guide rail (6), a first electric push rod (7), a second electric push rod (16), a front measuring vehicle (8), a first supporting block (11) and a second supporting block (12); The upper surface of the tool base (1) is provided with a plurality of linear guide rails (6), the first upright post (2) and the second upright post (3) are slidably arranged on the upper surface of the tool base (1) through the linear guide rails (6), and the first upright post (2) and the second upright post (3) are symmetrically arranged relative to the central axis of the tool base (1); A first electric push rod (7) and a second electric push rod (16) are arranged between the first upright (2) and the second upright (3), a telescopic rod of the first electric push rod (7) is connected with the first upright (2), and a telescopic rod of the second electric push rod (16) is connected with the second upright (3); The first electric push rod (7) and the second electric push rod (16) are used for changing the distance between the first upright (2) and the second upright (3); the second upright post (2) and the second upright post (3) are respectively provided with a slideway, a first supporting block (11) is fixedly connected with a nut of the first screw nut pair (4), the first supporting block (11) is in sliding connection with the slideway on the second upright post (2), a second supporting block (12) is fixedly connected with a nut of the second screw nut pair (5), and the second supporting block (12) is in sliding connection with the slideway on the second upright post (3); a first supporting frame (13) is arranged on the first supporting block (11), and a second supporting frame (14) is arranged on the second supporting block (12); The head of the aircraft is fixed between the first upright (2) and the second upright (3) through a first support frame (13) and a second support frame (14); the front measuring trolley (8) is positioned below the tool base (1); The rear vehicle mechanism comprises a rear measuring vehicle (9) and a third supporting frame (10); The support frame (10) is used for clamping the tail of the aircraft, and the rear measuring vehicle (9) is located below the third support frame (10).
2. A centroid measurement system for a winged aircraft according to claim 1 characterized in that the front (8) and rear (9) measuring vehicles are provided with load cells (15) at each of the four bottom corners of the upper surface.
3. Centroid measurement method for a centroid measurement system for a winged aircraft according to claim 1 characterized in that the method comprises in particular the following steps: step one, recording measured values of 4 weighing sensors on a front measuring vehicle and measured values of 4 weighing sensors on a rear measuring vehicle when no load exists; measuring the coordinates of the geometric center of the tool base (1) under a reference coordinate system, the coordinates of 3 reference points on the front measuring vehicle under the reference coordinate system and the coordinates of 3 reference points on the rear measuring vehicle under the reference coordinate system by using a laser tracker when in no-load; Obtaining coordinates of the 4 weighing sensor bearing points on the front measuring vehicle under a reference coordinate system according to the coordinate conversion relation between the 4 weighing sensor bearing points on the front measuring vehicle and the 3 reference points on the front measuring vehicle; obtaining coordinates of the 4 weighing sensor bearing points on the rear measuring vehicle under a reference coordinate system according to the coordinate conversion relation between the 4 weighing sensor bearing points on the rear measuring vehicle and the 3 reference points on the rear measuring vehicle; Step two, calculating a conversion matrix from a sensor coordinate system of the front measuring vehicle to a reference coordinate system according to the coordinates of 3 reference points on the front measuring vehicle under the reference coordinate system, the coordinates of the geometric center of the tool base (1) under the reference coordinate system and the coordinates of 4 weighing sensor bearing points on the front measuring vehicle under the reference coordinate system; similarly, a conversion matrix from a sensor coordinate system of the rear measuring vehicle to a reference coordinate system is obtained; step three, obtaining coordinates of 4 weighing sensor bearing points on the front measuring vehicle under the front measuring vehicle sensor coordinate system according to a conversion matrix from the front measuring vehicle sensor coordinate system to the reference coordinate system and coordinates of 4 weighing sensor bearing points on the front measuring vehicle under the reference coordinate system, and marking sitting marks of the 4 weighing sensor bearing points on the front measuring vehicle under the front measuring vehicle sensor coordinate system as follows ; According to the coordinates of the 4 weighing sensor bearing points on the front measuring vehicle under the front measuring vehicle sensor coordinate system and the coordinates of the 3 reference points on the front measuring vehicle under the reference coordinate system, calculating a conversion matrix from the front measuring vehicle reference coordinate system to the reference coordinate system; Similarly, according to a transformation matrix from the sensor coordinate system of the rear measuring vehicle to the reference coordinate system and the coordinates of the 4 weighing sensor bearing points on the rear measuring vehicle under the reference coordinate system, the coordinates of the 4 weighing sensor bearing points on the rear measuring vehicle under the sensor coordinate system of the rear measuring vehicle are obtained; According to the coordinates of 4 weighing sensor bearing points on the rear measuring vehicle under the sensor coordinate system of the rear measuring vehicle and the coordinates of 3 reference points on the rear measuring vehicle under the reference coordinate system, calculating a conversion matrix from the reference coordinate system of the rear measuring vehicle to the reference coordinate system; Step four, calculating a conversion matrix from the front measuring vehicle sensor coordinate system to the front measuring vehicle reference coordinate system according to the conversion matrix from the front measuring vehicle reference coordinate system to the reference coordinate system and the conversion matrix from the front measuring vehicle sensor coordinate system to the reference coordinate system; Calculating a conversion matrix from the rear measuring vehicle sensor coordinate system to the rear measuring vehicle reference coordinate system according to the conversion matrix from the rear measuring vehicle reference coordinate system to the reference coordinate system and the conversion matrix from the rear measuring vehicle sensor coordinate system to the reference coordinate system; loading the tested aircrafts on the front measuring vehicle and the rear measuring vehicle, and initializing the aircrafts on the front measuring vehicle and the rear measuring vehicle to be in a horizontal state; Step six, recording the measured values of 4 weighing sensors on the front measuring vehicle and the measured values of 4 weighing sensors on the rear measuring vehicle in a horizontal state, and obtaining the coordinates of 4 positioning points on the tested aircraft in the horizontal state under a reference coordinate system, 3 reference points on the front measuring vehicle and the coordinates of 3 reference points on the rear measuring vehicle under the reference coordinate system by utilizing a laser tracker; According to the coordinates of 3 reference points on the front measuring vehicle under the reference coordinate system and the coordinates of 4 positioning points on the tested aircraft under the reference coordinate system, calculating a conversion matrix from the aircraft coordinate system to the reference coordinate system and a conversion matrix from the front measuring vehicle reference coordinate system to the reference coordinate system under the horizontal state; according to the coordinates of 3 reference points on the rear measuring vehicle under the reference coordinate system and the coordinates of 4 positioning points on the tested aircraft under the reference coordinate system, calculating a conversion matrix from the aircraft coordinate system to the reference coordinate system and a conversion matrix from the reference coordinate system of the rear measuring vehicle under the horizontal state; Step seven, according to the conversion matrix from the aircraft coordinate system to the reference coordinate system and the conversion matrix from the reference coordinate system of the front measuring vehicle to the reference coordinate system in the horizontal state, obtaining the conversion matrix from the aircraft coordinate system to the reference coordinate system of the front measuring vehicle; obtaining a conversion matrix from the aircraft coordinate system to the rear measuring vehicle reference coordinate system according to the conversion matrix from the aircraft coordinate system to the reference coordinate system and the conversion matrix from the rear measuring vehicle reference coordinate system to the reference coordinate system in a horizontal state; Step eight, obtaining a conversion matrix between the aircraft coordinate system and the front measuring vehicle sensor coordinate system under the horizontal attitude according to the conversion matrix between the front measuring vehicle sensor coordinate system and the front measuring vehicle reference coordinate system and the conversion matrix between the aircraft coordinate system and the front measuring vehicle reference coordinate system; according to the conversion matrix from the rear measuring vehicle sensor coordinate system to the rear measuring vehicle reference coordinate system and the conversion matrix from the aircraft coordinate system to the rear measuring vehicle reference coordinate system, obtaining a conversion matrix from the aircraft coordinate system to the rear measuring vehicle sensor coordinate system under the horizontal attitude; Step nine, subtracting the measured values of the weighing sensors at the corresponding positions in the step six and the step one to obtain a difference value corresponding to the weighing sensor at each position; respectively establishing a static moment balance equation set under a front measuring vehicle sensor coordinate system and a rear measuring vehicle sensor coordinate system, and calculating the projection point coordinates of the resultant force points of the front measuring vehicle and the projection point coordinates of the resultant force points of the rear measuring vehicle in a horizontal state; Step ten, converting the projection point coordinates of the resultant force points of the front measuring vehicle into the aircraft coordinate system according to a conversion matrix between the aircraft coordinate system and the front measuring vehicle sensor coordinate system, and establishing a first gravity action line equation of the front measuring vehicle in the aircraft coordinate system according to the conversion result; similarly, converting the projection point coordinates of resultant force points of the rear measuring vehicle into the aircraft coordinate system according to a conversion matrix from the aircraft coordinate system to the rear measuring vehicle sensor coordinate system, and establishing a first gravity action line equation of the rear measuring vehicle; Step eleven, the aircraft is in an inclined state by improving the height of the front end of the aircraft, and the steps six to ten are repeatedly executed in the inclined state of the aircraft to obtain a second gravity action line equation of the front measuring vehicle and a second gravity action line equation of the rear measuring vehicle; Step twelve, determining the resultant force point coordinates of the front measuring vehicle according to the first gravity acting line equation of the front measuring vehicle and the second gravity acting line equation of the front measuring vehicle ; Determining the resultant force point coordinates of the rear measuring vehicle according to the first gravity acting line equation of the rear measuring vehicle and the second gravity acting line equation of the rear measuring vehicle ; And thirteen, combining the resultant force point coordinates of the front measuring vehicle and the resultant force point coordinates of the rear measuring vehicle to obtain the three-dimensional centroid coordinates of the tested aircraft.
4. A centroid measurement method for a centroid measurement system of a winged aircraft according to claim 3, wherein the transformation matrix of the front measurement car sensor coordinate system to the reference coordinate system is calculated according to the coordinates of 3 reference points on the front measurement car under the reference coordinate system, the coordinates of the geometric center of the tooling base (1) under the reference coordinate system and the coordinates of 4 weighing sensor bearing points on the front measurement car under the reference coordinate system, specifically: Marking the geometric center of the tool base (1) as a sitting mark under a reference coordinate system The first on the front measuring vehicle The seating marks of the load cell bearing points under the reference coordinate system are as follows Marking the seats of 3 reference points on the front measuring vehicle under a reference coordinate system as ; Performing plane fitting on coordinates of 4 weighing sensor bearing points on a front measuring vehicle to obtain a plane Taking the geometric center of the tool base (1) as the origin of a front measuring vehicle sensor coordinate system, and taking the 1 st reference point on the front measuring vehicle Projected to a plane Obtaining the projection point Connecting projection points Sum point Obtaining the projection point Pointing point For a plane Each normal direction of (1) is equal to the normal direction and is defined by the projection point Pointing point Taking the normal direction corresponding to the number product with the value of 1 as the Z-axis direction of the front measuring vehicle sensor coordinate system, and recording the Z-axis unit vector of the front measuring vehicle sensor coordinate system under the reference coordinate system as ; The method comprises the steps of making a vector of a1 st sensor weighing key point on a front measuring vehicle with the geometric center of a tool base (1), unitizing the vector of the 1 st sensor weighing key point on the front measuring vehicle with the geometric center of the tool base (1), wherein the obtained unit vector is an X-axis unit vector of a front measuring vehicle sensor coordinate system, recording the X-axis unit vector of the front measuring vehicle sensor coordinate system under a reference coordinate system as follows ; Make Z-axis unit vector And X-axis unit vector The unit vector of the Y axis of the front measuring vehicle sensor coordinate system under the reference coordinate system is obtained as follows ; Conversion matrix from front measuring vehicle sensor coordinate system to reference coordinate system The method comprises the following steps: Wherein, the Representing the transformation matrix of the sensor coordinate system of the front measuring vehicle to the reference coordinate system.
5. The method for measuring the mass center of the mass center measuring system for the winged aircraft according to claim 4, wherein a static moment balance equation set is established under a front measuring vehicle sensor coordinate system, and projection point coordinates of resultant force points of the front measuring vehicle in a horizontal state are calculated, wherein the method comprises the following steps: The static moment balance equation set is: Wherein: Representing the coordinates of the 1 st weighing sensor bearing point on the front measuring vehicle in the X S axis direction of the front measuring vehicle sensor coordinate system; Representing the coordinates of the 1 st weighing sensor bearing point on the front measuring vehicle in the Y S axis direction of the front measuring vehicle sensor coordinate system; representing the coordinates of the 2 nd weighing sensor bearing point on the front measuring vehicle in the X S axis direction of the front measuring vehicle sensor coordinate system; representing the coordinates of the 2 nd weighing sensor bearing point on the front measuring vehicle in the Y S axis direction of the sensor coordinate system of the front measuring vehicle; representing the coordinates of the 3 rd weighing sensor bearing point on the front measuring vehicle in the X S axis direction of the front measuring vehicle sensor coordinate system; representing the coordinates of the 3 rd weighing sensor bearing point on the front measuring vehicle in the Y S axis direction of the front measuring vehicle sensor coordinate system; representing the coordinates of the 4 th weighing sensor bearing point on the front measuring vehicle in the X S axis direction of the front measuring vehicle sensor coordinate system; Representing the coordinates of the 4 th weighing sensor bearing point on the front measuring vehicle in the Y S axis direction of the front measuring vehicle sensor coordinate system; representing the corresponding difference value of the 1 st weighing sensor of the front measuring vehicle, Representing the corresponding difference value of the 2 nd weighing sensor of the front measuring vehicle, Representing the corresponding difference value of the 3 rd weighing sensor of the front measuring vehicle, Representing the corresponding difference value of the 4 th weighing sensor of the front measuring vehicle; the first gravity action line of the front measuring vehicle passes through the point under the coordinate system of the front measuring vehicle sensor Because the direction of the gravity action line is vertically downward, the first gravity action line of the front measuring vehicle inevitably passes through a point under the coordinate system of the front measuring vehicle sensor 。
6. The method for measuring the mass center of the mass center measuring system of the winged aircraft according to claim 5, wherein the transformation matrix from the aircraft coordinate system to the front measuring vehicle sensor coordinate system transforms the projection point coordinates of the resultant force points of the front measuring vehicle into the aircraft coordinate system, specifically: Wherein, the Representation points Corresponding coordinates in the aircraft coordinate system, Point(s) Corresponding coordinates in the aircraft coordinate system.
7. The method according to claim 6, wherein in the step ten, a first gravity action line equation of the front survey vehicle is established in the aircraft coordinate system according to the conversion result, specifically: From the points Sum point Corresponding points in an aircraft coordinate system, and establishing a first gravity action line equation of the front measuring vehicle in the aircraft coordinate system: Wherein, the 、 And Three coordinate axis directions representing an aircraft coordinate system; The second gravity action line equation of the front measuring vehicle is as follows: Wherein, the And And representing the corresponding coordinates of two points, through which the second gravity action line of the front measuring vehicle passes, in the aircraft coordinate system.
8. A centroid measurement method for a centroid measurement system for a winged aircraft as set forth in claim 7 wherein the specific procedure of step twelve is: judging whether a first gravity action line equation of the front measuring vehicle and a second gravity action line equation of the front measuring vehicle are intersected or not; If the first gravity action line equation of the front measuring vehicle is intersected with the second gravity action line equation of the front measuring vehicle, the intersection point coordinate is the resultant force point coordinate of the front measuring vehicle, namely the resultant force point coordinate of the front measuring vehicle Simultaneously, the linear equation of two gravity action lines of the front measuring vehicle is satisfied: If the equation of the first gravity action line of the front measuring vehicle and the equation of the second gravity action line of the front measuring vehicle are not intersected, namely the two gravity action lines of the front measuring vehicle are different in space, taking the midpoint of the common vertical line of the first gravity action line of the front measuring vehicle and the second gravity action line of the front measuring vehicle as a resultant force point of the front measuring vehicle 。
9. A centroid measurement method for a centroid measurement system for a winged aircraft as in claim 8 wherein the specific procedure of step thirteen is: Wherein, the Representing the centroid coordinates of the aircraft under test, Representing the average load of the four sensors of the front measuring truck measured twice in the horizontal and inclined states, Representing the average load of the four sensors of the rear measuring vehicle in two measurements in horizontal and inclined states; Wherein, the , ; , 、、 And Representing the measurements of four sensors on a front survey vehicle when the aircraft is in a level condition, , 、、 And Representing the measurements of four sensors on a front survey vehicle while the aircraft is in a tilted state, Representing gravitational acceleration; , 、、 And Representing measurements from four sensors on the rear survey vehicle when the aircraft is in a level condition, , 、、 And Representing measurements from four sensors on a rear survey vehicle when the aircraft is in a tilted state.

Description

Centroid measurement system and method for winged aircraft Technical Field The invention belongs to the technical field of aircraft centroid measurement, and particularly relates to a centroid measurement system and method for a winged aircraft. Background The centroid is an important parameter for overall aircraft design, orbit control, attitude control. The accuracy of the centroid measurement affects the attitude control of the aircraft, and the measurement of the centroid of the mass provides design input for the attitude control system of the aircraft. Inaccurate centroid positioning can cause the increase of environmental disturbance moment and the inaccuracy of aircraft inertia tensor measurement, and both the two reasons can cause control moment calculation errors, so that uncorrectable attitude deviation is finally formed. Therefore, the research of the three-dimensional centroid measurement technology of the aircraft has great significance. The large-sized winged aerospace craft is of a non-revolving body structure and can be positioned at a specific position only. In the process of measuring the three-dimensional centroid of the product, the product cannot be turned over by 90 degrees to measure the centroid position parameter in the height direction due to the safety problem and the positioning problem, so that an inclined centroid test method is often adopted to measure the centroid position parameter in the height direction of the product. The fixed measuring table is adopted in common three-dimensional centroid measuring equipment, so that the measuring table cannot adapt to the measuring requirements of aircrafts with different diameters and different supporting widths, namely, the tool universality is poor, and the operation is complex and the efficiency is low when a measuring object is switched. The measurement of the three-dimensional centroid cannot be completed by means of one-time installation, namely, the inclination is used for replacing rollover 90 degrees to measure centroid position parameters in the height direction, the second time of manual installation is usually needed for measurement, product movement easily occurs in the inclination posture adjustment process, the measurement safety and precision are easily affected, and the existing inclination centroid measurement method is only suitable for centroid measurement of small aircrafts with the size within 3 meters. Disclosure of Invention The invention aims to solve the problems that an aircraft applicable to the existing measuring method is limited in size, complex in operation, low in efficiency and precision and easy to influence measuring safety, and provides a barycenter measuring system and method with adjustable support for a winged aircraft. The technical scheme adopted by the invention for solving the technical problems is as follows: In accordance with one aspect of the present invention, a centroid measurement system for a winged aircraft, the system specifically comprising a front and rear vehicle mechanism, wherein: The front vehicle mechanism comprises a tool base, a first upright post, a second upright post, a first screw nut pair, a second screw nut pair, a linear guide rail, a first electric push rod, a second electric push rod, a front measuring vehicle, a first supporting block and a second supporting block; the upper surface of the tool base is provided with a plurality of linear guide rails, the first upright post and the second upright post are slidably arranged on the upper surface of the tool base through the linear guide rails, and the first upright post and the second upright post are symmetrically arranged relative to the central axis of the tool base; A first electric push rod and a second electric push rod are arranged between the first upright post and the second upright post, a telescopic rod of the first electric push rod is connected with the first upright post, and a telescopic rod of the second electric push rod is connected with the second upright post; The first electric push rod and the second electric push rod are used for changing the distance between the first upright post and the second upright post; The second upright post and the second upright post are respectively provided with a slideway, the first supporting block is fixedly connected with a nut of the first screw-nut pair, the first supporting block is in sliding connection with the slideway on the second upright post, the second supporting block is fixedly connected with a nut of the second screw-nut pair, and the second supporting block is in sliding connection with the slideway on the second upright post; the first support block is provided with a first support frame, and the second support block is provided with a second support frame; the head of the aircraft is fixed between the first upright post and the second upright post through the first support frame and the second support frame; The front measuring vehicle is posi