A device and method for measuring the center of mass of a vehicle

Abstract

The application discloses a kind of aircraft mass center measuring device and measuring method, the measuring device includes base, bearing combination, shaft, storage board, measuring block, balancing body, pull rope fixed shaft, pull rope, electronic force gauge, level, locking pin and fixed seat;Base is connected with shaft by bearing combination, storage board is fixed with shaft, storage board is locked with base by locking pin, fixed seat is fixed on one side of storage board, the two side faces of fixed seat can install aircraft, the two side faces are perpendicular to the upper surface of storage board, the two side faces are parallel to the rotation center line of shaft, level, measuring block, balancing body and pull rope fixed shaft are installed on the other side of storage board, measuring block, balancing body can be individually slid and locked on the other side of storage board, the center line of pull rope fixed shaft is parallel to the rotation center line of shaft, electronic force gauge is connected with pull rope fixed shaft by pull rope, the device is simple in structure, without installing multiple sensors, operation, observation and data processing are convenient, and cost is low.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of measuring the mass center of a vehicle, and particularly relates to a device and method for measuring the mass center of a vehicle. BACKGROUND

[0002] The mass center of a vehicle is often measured at various stages of development of the vehicle and its subsystems. Most existing devices and methods for measuring the mass center use the principle of multi-point weighing, which requires multiple sensors to be installed at different parts of the measured object and simultaneously measured, and the measured data of the multiple sensors are comprehensively processed before the mass center can be calculated. The measuring device is complex in structure, high in cost, large in amount of measured data, and complicated in calculation process, and even requires a special data processing computer or processor. Some existing patents using the principle of moment balance also have shortcomings. Some of them ignore the friction moment in the moment balance analysis, resulting in a large measurement error. Some of the devices and methods for measuring the mass center are only suitable for symmetric structures and are not suitable for measuring the mass center in the direction of the asymmetric shape of the vehicle. SUMMARY

[0003] In view of the above, the present application provides a device and method for measuring the mass center of a vehicle, which uses the principle of moment balance, is simple in structure, does not require the installation of multiple sensors, is convenient to operate, observe and process data, and is low in cost. It is not only suitable for measuring the mass center in the direction of the symmetric shape of the vehicle, but also suitable for measuring the mass center in the direction of the asymmetric shape of the vehicle.

[0004] The technical scheme of the present application is as follows:

[0005] A device for measuring the mass center of a vehicle, comprising a base, a bearing combination, a rotating shaft, a placing plate, a measuring block, a balancing body, a fixed rope, an electronic force gauge, a level, a locking pin and a fixed seat. The base is fixed on the ground, the base is connected with the rotating shaft through the bearing combination, the center line of the rotation of the rotating shaft is parallel to the horizontal plane, the placing plate is fixed with the rotating shaft, the placing plate is locked with the base through the locking pin, the locking pin is installed on the base, the placing plate has a locking pin hole at the corresponding position, the fixed seat is fixed on one side of the placing plate, the two side surfaces of the fixed seat can be installed and fixed with the vehicle, the two side surfaces of the fixed seat are perpendicular to the upper surface of the placing plate, and the two side surfaces of the fixed seat are parallel to the center line of the rotation of the rotating shaft. The level, the measuring block and the balancing body are installed on the other side of the placing plate, the level is fixed with the placing plate, the level axis of the level is perpendicular to the center line of the rotation of the rotating shaft, and the level axis of the level is parallel to the upper surface of the placing plate.

[0006] Further, the measuring block is separately slid along the upper surface of the placing plate or is separately locked with the placing plate on the other side of the placing plate. During the separate sliding or locking of the measuring block, the mass center of the measuring block is always in the plane composed of the center line of the rotation of the rotating shaft and the center line of the fixed rope.

[0007] Further, the balancing body is separately slid on the other side of the placing plate or is separately locked relative to the placing plate.

[0008] Further, the pull rope fixing shaft is fixed with the placing plate, the center line of the pull rope fixing shaft is parallel to the rotation center line of the rotating shaft, the distance between the center line of the pull rope fixing shaft and the upper surface of the placing plate is equal to the distance between the rotation center line of the rotating shaft and the upper surface of the placing plate, the pull rope is connected with the pull rope fixing shaft through the center line of the pull rope fixing shaft, and the electronic force gauge is connected with the pull rope fixing shaft through the pull rope.

[0009] A method for measuring the center of mass of a vehicle, comprising the following steps:

[0010] Step 1, without installing the vehicle, without pulling the pull rope or without installing the electronic force gauge, sliding the measuring block along the direction away from the rotation center line of the rotating shaft until the level is approximately horizontal, locking the measuring block, measuring the distance between the center of mass of the measuring block and the rotation center line of the rotating shaft, and recording the distance as L4; then sliding the balancing body along the direction away from the rotation center line of the rotating shaft until the level is horizontal, locking the balancing body, and inserting the locking pin on the base into the locking pin hole of the placing plate;

[0011] Step 2, installing and fixing the vehicle on one side of the fixing base, and ensuring that the rear end surface of the vehicle is close to one side of the fixing base during installation;

[0012] Step 3, pulling the locking pin on the base out of the locking pin hole of the placing plate, applying a pulling force along the vertical direction of the plumb line by the electronic force gauge until the level is horizontal, recording the reading of the electronic force gauge at this time, and recording the reading as F;

[0013] Step 4, inserting the locking pin on the base into the locking pin hole of the placing plate, removing the vehicle from one side of the fixing base, and installing and fixing the vehicle on the other side of the fixing base, and ensuring that the rear end surface of the vehicle is close to the other side of the fixing base during installation;

[0014] Step 5, pulling the locking pin on the base out of the locking pin hole of the placing plate, reapplying the same pulling force F as in step 3 along the vertical direction of the plumb line by the electronic force gauge, keeping the pulling force along the vertical direction of the plumb line unchanged, loosening the measuring block, and slowly sliding the measuring block along the direction away from the rotation center line of the rotating shaft until the level is horizontal, locking the measuring block, and measuring the distance between the center of mass of the measuring block and the rotation center line of the rotating shaft, and recording the distance as L5;

[0015] Step 6, calculating the distance between the center of mass of the vehicle and the rear end surface of the vehicle according to the distance L4 and the distance L5 obtained in steps 1 and 5 as [G1*(L5-L4) / (2*G2)]-0.5*L3, wherein L3 is the distance between the two sides of the fixing base, G1 is the gravity of the measuring block, and G2 is the gravity of the vehicle.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] (1) The present application adopts a measuring block and a balancing body for double alignment, and the measuring block has the functions of alignment and measurement.

[0018] (2) The present application is designed with a locking pin, which realizes the connection and separation of the vehicle and the fixed seat in the state that the fixed seat is static.

[0019] (3) The present application uses the principle of moment balance, adjusts the position of the center of mass of the measuring block, and realizes the measurement of the center of mass of the vehicle with only one force measurement, without the need to install multiple sensors, and is convenient for operation, observation and data processing, and low in cost.

[0020] (4) The present application considers the friction moment in the moment balance analysis during measurement, and uses an electronic force gauge to measure the tension, which effectively improves the measurement accuracy.

[0021] (5) The present application is not only suitable for the measurement of the center of mass of the vehicle in the direction of symmetrical shape, but also suitable for the measurement of the center of mass of the vehicle in the direction of asymmetrical shape. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a schematic diagram of the present application vehicle center of mass measurement device.

[0023] Figure 2 It is a schematic diagram of the first measurement of the vehicle center of mass of the present application.

[0024] Figure 3 It is a schematic diagram of the second measurement of the vehicle center of mass of the present application.

[0025] Wherein, 1 - base, 2 - bearing combination, 3 - rotating shaft, 4 - placing plate, 5 - measuring block, 6 - balancing body, 7 - pull rope fixing shaft, 8 - pull rope, 9 - electronic force gauge, 10 - level, 11 - locking pin, 12 - fixed seat, 13 - vehicle, 14 - vehicle center of mass. DETAILED DESCRIPTION

[0026] The present application will be described in detail below in combination with the drawings and examples.

[0027] As Figure 1As shown, the application provides a kind of aircraft mass center measuring device, including base 1, bearing combination 2, shaft 3, storage plate 4, measuring block 5, balance body 6, pull rope fixing shaft 7, pull rope 8, electronic force gauge 9, level 10, locking pin 11 and fixed seat 12. Wherein, base 1 is fixed on the ground, base 1 is connected with shaft 3 by bearing combination 2, the rotation center line of shaft 3 is parallel with horizontal plane, storage plate 4 is fixed integrally with shaft 3 by screw, storage plate 4 and shaft 3 rotate around the rotation center line of shaft 3 relative to base 1, storage plate 4 is locked with base 1 by locking pin 11, locking pin 11 is installed on base 1, locking pin hole is left in the corresponding position of storage plate 4. Fixed seat 12 is fixed on the left side of the upper surface of storage plate 4, the left and right two sides of fixed seat 12 can be installed and fixed aircraft 13, the left and right two sides of fixed seat 12 are perpendicular to the upper surface of storage plate 4, the left and right two sides of fixed seat 12 are parallel to the rotation center line of shaft 3, the distance between the right side of fixed seat 12 and the rotation center line of shaft 3 is recorded as L2, and the distance between the left and right two sides of fixed seat 12 is recorded as L3. Level 10, measuring block 5 and balance body 6 are installed on the right side of storage plate 4, level 10 is fixed with storage plate 4, the level axis of level 10 is perpendicular to the rotation center line of shaft 3, and the level axis of level 10 is parallel to the upper surface of storage plate 4.

[0028] Measuring block 5 can be independently slid along the upper surface of storage plate 4 on the other side of storage plate 4, and measuring block 5 can be independently locked relative to storage plate 4. During the independent sliding and locking of measuring block 5, the mass center of measuring block 5 is always in the plane composed of the rotation center line of shaft 3 and the center line of pull rope fixing shaft 7. Balance body 6 can be independently slid and locked relative to storage plate 4 on the other side of storage plate 4. Pull rope fixing shaft 7 is installed on the right side in front of storage plate 4, the center line of pull rope fixing shaft 7 is parallel to the rotation center line of shaft 3, the distance between the center line of pull rope fixing shaft 7 and the upper surface of storage plate 4 is equal to the distance between the rotation center line of shaft 3 and the upper surface of storage plate 4, and the distance between the center line of pull rope fixing shaft 7 and the rotation center line of shaft 3 is recorded as L1. Pull rope 8 is connected with pull rope fixing shaft 7, pull rope 8 passes through the center line of pull rope fixing shaft 7, and electronic force gauge 9 is connected with pull rope 8.

[0029] The application also provides an aircraft mass center measuring method applied to the aircraft mass center measuring device, which specifically includes the following steps:

[0030] Step 1, as Figure 1As shown, the aircraft 13 is not installed, the pull rope 8 is not pulled tight or the electronic force gauge 9 is not installed, the measuring block 5 is first slid in the direction away from the rotation center line of the rotating shaft 3 until the level 10 is approximately horizontal, the measuring block 5 is locked, the distance between the mass center of the measuring block 5 and the rotation center line of the rotating shaft 3 is measured and recorded as L4, the balancing body 6 is then slid in the direction away from the rotation center line of the rotating shaft 3 until the level 10 is horizontal, the balancing body 6 is locked, and the locking pin 11 on the base 1 is inserted into the locking pin hole of the placement plate 4;

[0031] Step 2, as shown in the figure, the aircraft 13 is installed and fixed on the right side of the fixed seat 12, and the rear end surface of the aircraft 13 is ensured to be close to the right side of the fixed seat 12 during installation; Figure 2

[0032] Step 3, as shown in the figure, the locking pin 11 on the base 1 is pulled out of the locking pin hole of the placement plate 4, a pulling force is applied to the electronic force gauge 9 in the vertical downward direction along the plumb line, the pulling force is slowly increased from zero, the minimum indicated value of the electronic force gauge 9 is increased each time, the level 10 is observed during the application of the pulling force, until the level 10 is horizontal, and the indicated value of the electronic force gauge 9 at this time is recorded as F; Figure 2

[0033] According to the mechanical balance equation of the level when it is horizontal, the following equation is obtained:

[0034] (F*L1)-G2*(L2-A)-M=0 (1)

[0035] Wherein, G2 is the weight of the aircraft 13, A is the distance between the mass center 14 of the aircraft and the rear end surface of the aircraft 13, and M is the friction torque;

[0036] Step 4, as shown in the figure, the locking pin 11 on the base 1 is inserted into the locking pin hole of the placement plate 4, the aircraft 13 is removed from the right side of the fixed seat 12 and installed and fixed on the left side of the fixed seat 12, and the rear end surface of the aircraft 13 is ensured to be close to the left side of the fixed seat 12 during installation; Figure 3 Step 5, as shown in the figure, the locking pin 11 on the base 1 is pulled out of the locking pin hole of the placement plate 4, the same pulling force F as in step 3 is applied to the electronic force gauge 9 in the vertical downward direction along the plumb line, the pulling force in the vertical downward direction along the plumb line is kept unchanged, the measuring block 5 is loosened, the measuring block 5 is slowly slid in the direction away from the rotation center line of the rotating shaft 3 until the level 10 is horizontal, the measuring block 5 is locked, and the distance between the mass center of the measuring block 5 and the rotation center line of the rotating shaft 3 is measured and recorded as L5;

[0037] Figure 3 According to the mechanical balance equation of the level when it is horizontal, the following equation is obtained:

[0038]

[0039] ​​​​(F*L1)+ G1*(L5-L4)- G2*(L2+L3+A)-M=0 (2)

[0040] Where G2 is the gravity of the vehicle 13, A is the distance between the center of mass 14 of the vehicle and the rear end face of the vehicle 13, and M is the frictional torque.

[0041] Step 6: Solve equations (1) and (2) to obtain the distance between the center of mass 14 of the vehicle and the rear end face of the vehicle 13:

[0042] A=[G1*(L5-L4) / (2*G2)]-0.5*L3 (3)

[0043] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for measuring the center of mass of a spacecraft, the method being applied to a spacecraft center of mass measuring device, the measuring device comprising a base, a bearing assembly, a rotating shaft, a mounting plate, a measuring block, a balance body, a rope fixing shaft, a rope, an electronic force gauge, a level, a locking pin, and a fixing seat; wherein, The base is fixed to the ground, and the base and the rotating shaft are connected by a bearing assembly. The rotation center line of the rotating shaft is parallel to the horizontal plane. The placement plate is fixed to the rotating shaft, and the placement plate and the base are locked together by locking pins installed on the base. Locking pin holes are provided at corresponding positions on the placement plate. A fixing seat is fixed to one side of the placement plate. The two sides of the fixing seat can be used to mount and fix the aircraft. Both sides of the fixing seat are perpendicular to the upper surface of the placement plate and parallel to the rotation center line of the rotating shaft. A level, measuring block, and balancing body are installed on the other side of the placement plate. The level is fixed to the placement plate, and the leveling axis of the level is perpendicular to the rotation center line of the rotating shaft and parallel to the upper surface of the placement plate. The measurement method includes the following steps: Step 1: Without installing the aircraft, with the rope not taut or the electronic force gauge not installed, first slide the measuring block along the rotation center line away from the axis of rotation until the level is roughly horizontal, then lock the measuring block, measure the distance between the center of mass of the measuring block and the rotation center line of the axis of rotation, and record it as L4; then slide the balance body along the rotation center line away from the axis of rotation until the level is horizontal, lock the balance body, and insert the locking pin on the base into the locking pin hole of the placement plate; Step 2: Install and secure the aircraft to one side of the mounting base, ensuring that the rear end of the aircraft is flush with one side of the mounting base during installation; Step 3: Pull the locking pin on the base out of the locking pin hole on the shelf, and apply a pulling force vertically downward along the plumb line using an electronic force gauge until the level is horizontal. Record the reading of the electronic force gauge at this time as F. Step 4: Insert the locking pin on the base into the locking pin hole of the storage plate. Remove the aircraft from one side of the mounting base and install it on the other side of the mounting base. During installation, ensure that the rear end face of the aircraft is close to the other side of the mounting base. Step 5: Pull the locking pin on the base out of the locking pin hole on the plate. Reapply the same pulling force F as in Step 3 along the vertical downward direction using the electronic force gauge. Keep the pulling force applied along the vertical downward direction unchanged. Release the measuring block and slowly slide the measuring block along the rotation center line away from the rotating shaft until the level is horizontal. Lock the measuring block and measure the distance between the center of mass of the measuring block and the rotation center line of the rotating shaft, and record it as L5. Step 6: Based on the distances L4 and L5 obtained in Step 1 and Step 5, calculate the distance between the center of mass of the vehicle and the rear end face of the vehicle as [G1*(L5-L4) / (2*G2)]-0.5*L3, where L3 is the distance between the two sides of the fixed base, G1 is the weight of the measuring block, and G2 is the weight of the vehicle.

2. The measurement method as described in claim 1, characterized in that, The measuring block slides independently along the upper surface of the shelf on the other side or locks independently relative to the shelf. During the independent sliding or locking process, the center of mass of the measuring block is always in the plane formed by the rotation center line of the rotating shaft and the center line of the fixed shaft of the pull rope.

3. The measurement method as described in claim 2, characterized in that, The balancer can slide independently on the other side of the shelf or lock independently relative to the shelf.

4. The measurement method as described in claim 3, characterized in that, The pull rope fixing shaft is fixed to the shelf, and the center line of the pull rope fixing shaft is parallel to the rotation center line of the rotating shaft. The distance between the center line of the pull rope fixing shaft and the upper surface of the shelf is equal to the distance between the rotation center line of the rotating shaft and the upper surface of the shelf. The pull rope passes through the center line of the pull rope fixing shaft and is connected to the pull rope fixing shaft. The electronic force gauge is connected to the pull rope fixing shaft through the pull rope.

Images