CN114705361A

CN114705361A - Gravity center weight measuring system and method for irregular object

Info

Publication number: CN114705361A
Application number: CN202210297086.3A
Authority: CN
Inventors: 万明; 刘钢; 谭楚斌; 何小婷; 何念; 谭红军; 景慧
Original assignee: Hengyang North Photoelectricity Information Technology Co ltd
Current assignee: Hengyang North Photoelectricity Information Technology Co ltd
Priority date: 2022-03-24
Filing date: 2022-03-24
Publication date: 2022-07-05

Abstract

The invention discloses a gravity center weight measuring system and a gravity center weight measuring method for irregular objects, belongs to the technical field of application of mechanical testing devices, and solves the problems of low measuring precision and measuring efficiency when the mass is measured by the existing jack type, suspension type and weighing platform type measuring methods. The gravity center weight measuring system for the irregular object comprises a test board and a computer which are connected through signals; the test bench is used for realizing acquisition and sending of sensor data; and the computer is responsible for receiving the sensor data and calculating the weight and the gravity coordinate value of the irregular object according to the sensor data. The invention can quickly and accurately measure the gravity center and the weight of the irregular object.

Description

Gravity center weight measuring system and method for irregular object

Technical Field

The invention relates to the technical field of object gravity center measurement, in particular to a gravity center weight measurement system and a gravity center weight measurement method for an irregular object.

Background

The weight measurement of the gravity center of a general object is respectively carried out by adopting a suspension wire balance method, and the weight measurement is carried out by adopting a weighing instrument, so that the measurement precision and the measurement efficiency are low. The digital weight gravity center measuring instrument formed by the three pressure sensors and the pressure data measuring and calculating circuit can quickly and accurately measure the gravity center and the weight of irregular objects.

The determination of the weight and the position of the center of gravity of an object is an essential ring in engineering, and is particularly important in the application of objects with safety requirements. At present, the measurement of objects with large weight is generally based on a moment balance principle, and the measurement modes such as a jack type, a suspension type and a weighing platform type are mainly adopted.

However, when the jack type is adopted for measurement, the measurement precision is low due to the existence of lateral force, and the measurement repeatability is poor; suspension type measurement needs to be carried out for multiple times to determine the gravity center, the operation is complex, the method is only suitable for thin plate measurement, and the measurement error of a solid object is large; the weighing platform method is to put a weighing platform down at each force-measuring supporting point without the influence of lateral force, but the level adjustment is difficult, and the measurement precision is influenced.

Disclosure of Invention

In view of the above analysis, the present invention aims to provide a system and a method for measuring the gravity center and weight of an irregular object, so as to solve the problems of low measurement accuracy and measurement efficiency when the mass is measured by the existing jack type, suspension type and weighing platform type measurement methods.

The purpose of the invention is mainly realized by the following technical scheme:

in one aspect, the invention provides a gravity center weight measurement system for irregular objects, which comprises a test board and a computer which are connected through signals;

the test bench is used for realizing the acquisition and the transmission of sensor data; and the computer is used for receiving the sensor data and calculating the weight and the gravity coordinate value of the irregular object according to the sensor data.

In one possible design, the test stand includes a load-bearing platform, a sensor, and a data acquisition board;

the bearing platform is used for fixing the sensor and bearing the irregular object; the irregular object is fixed on the bearing platform through the fixing tool, and the sensor is used for collecting the weight of the irregular object; the data acquisition board is used for controlling the analog-to-digital conversion to complete signal acquisition and sending an acquisition result to the computer.

In one possible design, a level gauge is arranged on the bearing platform and used for ensuring that the bearing platform is in a horizontal state;

the edge of the table top of the bearing platform is provided with a plurality of vertical positioning plates which are used for ensuring that the fixing tool is placed along the edge of the bearing platform; fixing the irregular object on a fixing tool;

the sensors include a first sensor, a second sensor and a third sensor; the data acquisition board comprises an instrument amplifier, a filter, an A/D (analog/digital) conversion module, an MCU (microprogrammed control unit) and a serial port which are sequentially connected in a signal manner;

the A/D analog-to-digital conversion module is used for converting the analog signals into digital signals, the MCU microcontroller is used for receiving the digital signals, and the digital signals are transmitted to the computer through the serial port.

In one possible design, the fixing tool comprises a rectangular fixing bottom plate and a fixing frame, wherein the fixing frame is erected on the rectangular fixing bottom plate and is arranged perpendicular to the rectangular fixing bottom plate;

the fixed frame comprises a rectangular steel plate, a first right-angled triangular steel plate and a second right-angled triangular steel plate; the rectangle steel sheet is located a long edge of rectangle PMKD, and first right angle triangle-shaped steel sheet and second right angle triangle-shaped steel sheet are located two short edges of rectangle PMKD respectively, and the right angle limit and the rectangle steel sheet fixed connection of first right angle triangle-shaped steel sheet and second right angle triangle-shaped steel sheet.

On the other hand, the invention also provides a gravity center weight measuring method for irregular objects, which adopts the gravity center weight measuring system and comprises the following steps:

step 1, defining a coordinate system of a bearing platform as O-XYZ, and defining a barycentric coordinate of an irregular object as G (x0, y0, z 0); fixing the irregular object on the bearing platform through a fixing piece to enable the irregular object to be in a static state;

step 2, measuring the weight of the irregular object and the center-of-gravity component value of the X, Y axis;

step 3, rotating the irregular object clockwise by 90 degrees along the ZOY plane, then placing the irregular object on the bearing platform after rotating, measuring the weight of the irregular object again, and measuring the gravity center component value of the X, Z axis;

and 4, analyzing and comparing the weight of the irregular object measured twice and the measurement precision of the X axis by using a computer, and calculating the weight of the irregular object and XYZ barycentric coordinates according to a barycentric calculation principle.

Further, in step 2, the weight of the irregular object is obtained by the following process:

starting a weight and gravity center measuring system, wherein the supporting force of the irregular object measured by a first sensor is F1, the supporting force of the irregular object measured by a second sensor is F2, and the supporting force of the irregular object measured by a third sensor is F3; the weight of the irregular object is:

M*g＝F1+F2+F3 (1)

wherein M is the mass of the irregular object, g is the acceleration of gravity, and F1 is the supporting force provided by the first sensor; f2 is the supporting force provided by the second sensor; f3 is the support force provided by the third sensor.

Further, in step 2, the weight and gravity center measuring system is started, pressure signals collected by the first sensor, the second sensor and the third sensor are conditioned by the instrument amplifier and the filter, the conditioned analog signals are converted into digital signals by the A/D analog-to-digital conversion module, the digital signals are received by the MCU microcontroller and then transmitted to the computer for processing by the serial port, and the supporting force F1 of the irregular object measured by the first sensor, the supporting force F2 of the irregular object measured by the second sensor and the supporting force F3 of the irregular object measured by the third sensor are obtained.

Further, in step 2, the process of measuring the values of the components of the center of gravity of the X and Y axes of the irregular object is:

M*g*y0＝F1*Y1+F2*Y2+F3*Y3 (2)

M*g*x0＝F1*X1+F2*X2+F3*X3 (3)

the horizontal and vertical coordinates of the gravity center of the irregular object are calculated as follows:

x0＝(F1*X1+F2*X2+F3*X3)/M*g

y0＝(F1*Y1+F2*Y2+F3*Y3)/M*g

wherein M is the mass of the irregular object, g is the gravitational acceleration, F1 is the supporting force of the irregular object measured by the first sensor, F2 is the supporting force of the irregular object measured by the second sensor, F3 is the supporting force of the irregular object measured by the third sensor, and a (X1, Y1,0) is the coordinates of the first sensor; b (X2, Y2,0) is the coordinates of the second sensor; c (X3, Y3,0) is the coordinates of the third sensor.

Further, in step 3, the irregular object is rotated by 90 degrees and then placed on the bearing platform, and the weight of the irregular object is measured again; the weight measurement process of the irregular object is as follows:

M*g＝F1'+F2'+F3' (1)

wherein M is the mass of the irregular object, g is the gravitational acceleration, F1' is the supporting force of the irregular object measured by the first sensor after the irregular object rotates 90 degrees clockwise along the ZOY plane, F2' is the supporting force of the irregular object measured by the second sensor after the irregular object rotates 90 degrees clockwise along the ZOY plane, and F3' is the supporting force of the irregular object measured by the third sensor after the irregular object rotates 90 degrees clockwise along the ZOY plane.

Further, in step 3, after the irregular object is rotated by 90 ° clockwise along the ZOY plane, the abscissa of the barycentric position of the irregular object is x 0', the ordinate is changed to the ordinate before the rotation, and the process of measuring the barycentric component values of X, Z axes is:

x0’＝(F1'*X1+F2'*X2+F3'*X3)/M*g；

z0＝(F1'*Y1+F2'*Y2+F3'*Y3)/M*g；

wherein M is the mass of the irregular object, g is the gravitational acceleration, F1' is the supporting force of the irregular object measured by the first sensor, F2' is the supporting force of the irregular object measured by the second sensor, and F3' is the supporting force of the irregular object measured by the third sensor; a (X1, Y1,0) is the coordinates of the first sensor; b (X2, Y2,0) is the coordinates of the second sensor; c (X3, Y3,0) is the coordinates of the third sensor.

Further, in the step 1, when placing the irregular object, the edge of the irregular object is ensured to be tightly attached to the bearing platform.

Compared with the prior art, the invention can realize at least one of the following beneficial effects:

(1) the gravity center weight measurement system provided by the invention is suitable for measuring the gravity center and the weight of a regular or irregular object, the measurement system is simple in composition, and the measurement method has the characteristics of simplicity in operation, convenience in maintenance, high measurement precision and the like.

(2) The gravity center weight measuring system has the automatic zero calibration function, can solve the zero drift problem under different environments, and reduces the measurement error.

(3) According to the gravity center weight measuring instrument, the high-precision pressure sensor is used for collecting pressure signals of irregular objects, the signals are conditioned through the instrument amplifier and the second-order low-pass filter, common-mode signals can be effectively inhibited, effective differential signals are amplified, the measuring precision is improved, and the effective measuring range is enlarged.

(4) The test board can be obliquely arranged, and irregular objects are fixed on the bearing platform through the fixing tool during oblique arrangement; according to the invention, the first sensor, the second sensor and the third sensor are integrated on the same test board, and the weight and gravity center measuring system is formed by the three pressure sensors for acquiring pressure data, the data acquisition board and the calculating mechanism, so that the gravity center and the weight of an irregular object can be measured quickly and accurately.

In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

FIG. 1 is a schematic diagram of the force applied to an irregular object according to the present invention in a balanced state;

FIG. 2 is a schematic diagram of the force-to-axis distance experienced by an irregular object according to the present invention;

FIG. 3 is a schematic diagram of the gravity center calculation of the irregular object according to the present invention;

FIG. 4 is a schematic view of the irregular object in FIG. 3 rotated 90 clockwise along the ZOY plane;

FIG. 5 is a main flow chart of center of gravity measurement;

FIG. 6 is a schematic diagram of the system components of a center of gravity weight measurement system for irregular objects;

FIG. 7 is a block diagram of the components of a system for measuring the weight of the center of gravity for irregular objects;

FIG. 8 is a schematic structural diagram of a testing table;

fig. 9 is a schematic structural view of a fixing tool for an irregular object provided in embodiment 1;

fig. 10 is a schematic structural view of a fixture for fixing an irregular object provided in embodiment 2;

fig. 11 is a schematic view of fixing an irregular object by using the fixing tool provided in embodiment 1;

FIG. 12 is a schematic view of the fixing tool provided in example 1 after the fixing tool is used for fixing the irregular object and rotating the irregular object by 90 degrees clockwise along the ZOY plane.

Reference numerals:

a first vertical positioning plate; 2-a second vertical positioning plate; 3-a third vertical positioning plate; 4-a level meter; 5-a rectangular fixed bottom plate; 6-rectangular steel plate; 7-a first right-angled triangular steel plate; 8-a second right-angled triangular rectangular steel plate; 9-a first sensor; 10-a second sensor; 11-a third sensor; 12-a test bench; 13-adjusting the feet. 14-fixing block; 15-a locking block; 16-fixing a tool; 17-a first guide fixing plate; 18-a second guide fixing plate; 19-a third guide fixing plate; 20-rectangular bottom plate with groove.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention and not to limit its scope.

In one aspect, the present invention provides a gravity center weight measuring system for irregular objects, as shown in fig. 6 and 7, comprising a test stand 12 and a computer; the test bench 12 is used for acquiring and sending sensor data; and the computer is used for receiving the sensor data and calculating the weight and the gravity coordinate value of the irregular object according to the sensor data.

It should be noted that the test platform 12 of the present invention includes a bearing platform, a sensor and a data acquisition board, wherein the bearing platform is used for fixing the sensor and bearing an irregular object; the sensor is used for acquiring the weight of the irregular object; the data acquisition board is used for controlling the analog-to-digital conversion to complete signal acquisition and sending an acquisition result to the computer.

In order to adjust the height of the test bench 12, the test bench 12 of the present invention is in the shape of a table, and the adjusting feet 13 are provided at the legs of the test bench 12, so that the overall height of the test bench 12 can be adjusted by adjusting the adjusting feet 13.

As shown in fig. 1 and 2, the sensor of the present invention includes a first sensor 9, a second sensor 10, and a third sensor 11; the first sensor 9, the second sensor 10 and the third sensor 11 are all used for measuring the pressure of the irregular object at different positions. The data acquisition board comprises an instrument amplifier, a filter, an A/D (analog/digital) conversion module, an MCU (microprogrammed control unit) and a serial port which are sequentially connected in a signal manner; the A/D analog-to-digital conversion module is used for converting the analog signals into digital signals, the MCU microcontroller is used for receiving the digital signals, and the digital signals are transmitted to the computer through the serial port.

It should be noted that, when the first sensor 9, the second sensor 10 and the third sensor 11 are arranged, the arrangement principle is that the projection of the gravity center of the irregular object on the carrying platform is in the closed area enclosed by the first sensor 9, the second sensor 10 and the third sensor 11.

Compared with the prior art, the invention uses the high-precision first pressure sensor, the second pressure sensor and the third pressure sensor to collect three paths of pressure signals of an irregular object, then conditions the pressure signals by the instrument amplifier and the second-order low-pass filter, converts the analog signals (pressure signals) into digital signals by the A/D analog-to-digital conversion module, transmits the digital signals to the PC end computer through the serial port after the digital signals are received by the MCU microcontroller, completes the calculation process of the gravity center through the computer, and displays the result on the display interface of the computer.

It should be noted that the load-bearing platform of the present application is provided with a level 4, and the level 4 is used for ensuring that the load-bearing platform is in a horizontal state.

In order to ensure the positioning of irregular objects, a plurality of vertical positioning plates are arranged at the edge of the table top of the bearing platform, and the vertical positioning plates are used for ensuring that the fixing tool 16 is placed along the edge of the bearing platform; the irregular object is fixed on the fixing tool 16, so that the irregular object is ensured to be fixed along the edge position of the bearing platform.

It should be noted that the number of the vertical positioning plates in the present invention is 2-5, for example, the number of the vertical positioning plates in fig. 6 is two, and the number of the vertical positioning plates in fig. 8 is 3. The vertical positioning plate is arranged at the edge position of the bearing platform to ensure that the fixing tool 16 is also placed along the edge position of the bearing platform.

It should be noted that the measurement principle of the gravity center weight measurement system for irregular objects of the present invention is as follows: when the weight and the gravity center coordinate of an irregular object are measured, two principles according to are respectively as follows:

the first principle is as follows: "when the object is in the balance state, the resultant external force is zero"; the second principle is as follows: "the moment of the resultant force on any axis is equal to the algebraic sum of the moments of the component forces on the same axis".

As shown in fig. 1, when the irregular object is placed on the bearing platform and is in a static state, the action point is at the gravity center G (x, y, z) under the action of the gravity Mg which is vertically downward; the vertical upward supporting force of three sensors (a first sensor 9, a second sensor 10 and a third sensor 11) respectively acts on the three sensors, and the magnitude and the action point coordinates are respectively as follows: f1, F2, F3; (X1, Y1,0), (X2, Y2,0), (X3, Y3, 0). The basis when the weight of the irregular object is measured is as follows: "when the object is in the equilibrium state, the resultant external force is zero", there are: m × g ═ F1+ F2+ F3.

As shown in FIG. 2, taking the moment of F1 to the x-axis as an example, the intersection of the plane perpendicular to the x-axis passing through F1 is D, and the moment of F1 to the x-axis is equal to the moment of F1 to the D point. The magnitude M is F1 y1, where y1 is the ordinate of the first sensor 9, and the direction of the moment is to the right according to the right-hand screw rule. The moment of the supporting force is directed to the right and the gravity moment is directed to the left.

When taking the moment of F2 to the x-axis as an example, the intersection of the plane perpendicular to the x-axis passing through F2 is E, and the moment of F2 to the x-axis is equal to the moment of F2 to the D-point. The magnitude M is F2 y2, where y2 is the ordinate of the second sensor 10, and the direction of the moment is to the right according to the right-hand screw rule. The moment of the supporting force is directed to the right and the gravity moment is directed to the left.

When taking the moment of F3 to the x-axis as an example, a plane perpendicular to the x-axis passing through F3 intersects the x-axis at F, and the moment of F3 to the x-axis is equal to the moment of F3 to the D-point. The magnitude M is F3 y3, where y3 is the ordinate of the third sensor 11, and the direction of the moment is to the right according to the right-hand screw rule. The moment of the supporting force is directed to the right and the gravity moment is directed to the left.

2) Principle of gravity center calculation

Step 1, placing irregular objects according to the graph 3, ensuring that the edges of the irregular objects are tightly attached to vertical baffles arranged at the edges of the bearing platform, and according to a formula:

M*g＝F1+F2+F3 (1)；

wherein M is the mass of the irregular object, g is the gravity acceleration, and F1, F2 and F3 are respectively supporting forces provided by three sensors; the coordinate system of the test table 12 is O-XYZ.

Assuming a center of gravityThe coordinate is G (x0, y0, z0) according to "the moment of the resultant force on any axis is equal to the algebraic sum of the moments of the component forces on the same axis". The algebraic sum of the x-axis moments of the respective force components should be 0, and the algebraic sum of the z-axis moments should be zero. I.e. has sigma M_X＝0、∑M_Y＝0；

M*g*y0＝F1*Y1+F2*Y2+F3*Y3 (2)

M*g*x0＝F1*X1+F2*X2+F3*X3 (3)

Where a (X1, Y1) is the coordinates of the first sensor 9, B (X2, Y2) is the coordinates of the second coarse sensor, and C (X3, Y3) is the coordinates of the third sensor 11. According to the formula (2) and the formula (3), the abscissa and the ordinate of the gravity center are calculated respectively:

x0＝(F1*X1+F2*X2+F3*X3)/M*g

y0＝(F1*Y1+F2*Y2+F3*Y3)/M*g

and 2, rotating the irregular object clockwise 90 degrees (in the direction marked in figure 3) along the ZOY plane to obtain the state shown in figure 4.

After the rotation, the abscissa of the gravity center position of the irregular object is unchanged, the ordinate is changed into the vertical coordinate in fig. 1, the vertical coordinate is also changed, and the gravity center position is not used for calculating the gravity center position and is not required to be calculated. The moment to the X axis according to the resultant force is zero:

∑M_X＝0

obtaining the z-axis coordinate value when the state of FIG. 4 is placed:

x0’＝(F1'*X1+F2'*X2+F3'*X3)/M*g；

z0＝(F1'*Y1+F2'*Y2+F3'*Y3)/M*g；

wherein, F1', F2' and F3' are the corresponding pressure signals respectively collected by the first sensor 9, the second sensor 10 and the third sensor 11 when the irregular object is placed according to fig. 4.

At this point, sensor data is acquired twice, and the three-dimensional space coordinate G (x0, y0, z0) of the center of gravity when the irregular object is placed in the state of fig. 3 is obtained by flipping the irregular object once. The center of gravity of the object can be determined by the method.

Based on the principle, the invention also provides a gravity center weight measuring method for the irregular object, the gravity center weight measuring system is adopted, the gravity center calculating process of the irregular object is shown in figure 5, a power supply is started, a data acquisition board is electrified, and a computer is started; placing an irregular object, sending a command by an upper computer software end, acquiring data of three sensors by using a data acquisition board and a first data board, sending the data to a PC (personal computer), and calculating coordinates of an x axis and a y axis of a gravity center by software according to the received data; and turning over the weight to be measured, resending the command to read the sensor data, and calculating the barycentric z-axis coordinate. The method specifically comprises the following steps:

step 1, defining a coordinate system of a bearing platform as O-XYZ; defining the barycentric coordinate of the irregular object as G (x0, y0, z 0); fixing the irregular object on the bearing platform through a fixing tool 16 to enable the irregular object to be in a static state;

step 2, measuring the weight of the irregular object and the gravity center component values of x and y axes;

step 3, rotating the irregular object clockwise by 90 degrees along the ZOY plane, then placing the irregular object on a bearing platform after rotating, measuring the weight of the irregular object again, and measuring the gravity component values of the x axis and the z axis;

and 4, analyzing and comparing the weight of the irregular object measured twice and the measurement precision of the x axis by using a computer, and calculating the weight and the barycentric coordinate of the irregular object according to the barycentric calculation principle.

In step 1, when placing an irregular object, the level 4 is used to ensure that the bearing platform is in a horizontal state and ensure that the edge of the irregular object is tightly attached to the bearing platform.

In step 1, when measuring the irregular object, the weight and the center of gravity of the fixed tool 16 are measured, and then the weight of the fixed tool 16 is removed, that is, the measurement system is set to a zero state, and then the weight and the center of gravity of the irregular object are measured.

In step 1, the projection of G (x0, y0, z0) on the carrying platform is located in the area enclosed by the connecting line of the first sensor 9, the second sensor 10 and the third sensor 11.

In the step 2, the process of obtaining the weight of the irregular object is as follows:

starting a weight and gravity center measuring system, wherein the supporting force of the irregular object measured by the first sensor 9 is F1, the supporting force of the irregular object measured by the second sensor 10 is F2, and the supporting force of the irregular object measured by the third sensor 11 is F3; the weight of the irregular object is:

M*g＝F1+F2+F3 (1)

where M is the irregular object mass, g is the gravitational acceleration, and F1 is the supporting force provided by the first sensor 9; f2 is the supporting force provided by the second sensor 10; f3 is the support force provided by the third sensor 11.

It should be noted that, according to irregular objects with different shapes, different fixing tools 16 may be used to fix the irregular objects on the bearing platform, and before the weight of the irregular objects is obtained, the weight of the fixing tool 16 is weighed and then set to zero, so that the measurement system starts to measure the weight and the gravity center position of the irregular objects after being in an initial state.

In the step 2, the weight and gravity center measuring system is started, the pressure signals collected by the first sensor 9, the second sensor 10 and the third sensor 11 are conditioned by the instrumentation amplifier and the filter, the conditioned analog signals are converted into digital signals by the a/D analog-to-digital conversion module, the digital signals are received by the MCU microcontroller and transmitted to the computer through the serial port for processing, and the supporting force F1 of the irregular object measured by the first sensor 9, the supporting force F2 of the irregular object measured by the second sensor 10 and the supporting force F3 of the irregular object measured by the third sensor 11 are obtained.

In step 2, the process of measuring the values of the gravity center components of the irregular object in the x and y axes is as follows:

M*g*y0＝F1*Y1+F2*Y2+F3*Y3 (2)

M*g*x0＝F1*X1+F2*X2+F3*X3 (3)

the horizontal and vertical coordinates for calculating the gravity center of the irregular object are respectively as follows:

x0＝(F1*X1+F2*X2+F3*X3)/M*g

y0＝(F1*Y1+F2*Y2+F3*Y3)/M*g

where M is the mass of the irregular object, g is the gravitational acceleration, F1 is the supporting force of the irregular object measured by the first sensor 9, F2 is the supporting force of the irregular object measured by the second sensor 10, F3 is the supporting force of the irregular object measured by the third sensor 11, and a (X1, Y1,0) is the coordinates of the first sensor 9; b (X2, Y2,0) is the coordinates of the second sensor 10; c (X3, Y3,0) is the coordinates of the third sensor 11.

In the step 3, the irregular object is rotated by 90 degrees and then placed on the bearing platform, and the weight of the irregular object is measured again; the weight measurement process of the irregular object is as follows:

M*g＝F1'+F2'+F3' (4)

where M is the mass of the irregular object, g is the gravitational acceleration, F1' is the supporting force of the irregular object measured by the first sensor 9 after the irregular object rotates 90 ° clockwise along the ZOY plane, F2' is the supporting force of the irregular object measured by the second sensor 10 after the irregular object rotates 90 ° clockwise along the ZOY plane, and F3' is the supporting force of the irregular object measured by the third sensor 11 after the irregular object rotates 90 ° clockwise along the ZOY plane.

In step 3, after the irregular object is rotated 90 ° clockwise along the ZOY plane, the abscissa of the barycentric position of the irregular object is x 0' (same as x0 before flipping), the ordinate is the vertical coordinate before rotation, and the process of measuring the barycentric component values of the x and z axes is as follows:

x0’＝(F1'*X1+F2'*X2+F3'*X3)/M*g；

z0＝(F1'*Y1+F2'*Y2+F3'*Y3)/M*g；

wherein M is the mass of the irregular object, g is the gravitational acceleration, F1' is the supporting force of the irregular object measured by the first sensor 9, F2' is the supporting force of the irregular object measured by the second sensor 10, and F3' is the supporting force of the irregular object measured by the third sensor 11; a (X1, Y1,0) is the coordinates of the first sensor 9; b (X2, Y2,0) is the coordinates of the second sensor 10; c (X3, Y3,0) is the coordinates of the third sensor 11.

Compared with the prior art, the measuring method can synchronously measure two parameters of the weight and the gravity center of the irregular object, the weight and the horizontal coordinate of the gravity center of the irregular object are measured twice in the steps 2 and 3, the two measurement results are compared and analyzed (namely, the weight of the irregular object before being overturned is compared with the weight after being overturned, and x0 and x 0' are compared), the difference of the two weight measurement results is ensured to be within an error range, and the effectiveness and the precision of weight measurement are further improved by using two redundant measurement results.

It should be noted that, when the two weight measurement results are compared and are not within the error range, it is necessary to check the fastening degree of the fixing member to the irregular object and to maintain whether the carrying platform is in a horizontal state.

It should be noted that, because of the irregularity of the irregular object, direct measurement cannot be performed, the fixed tool 16 is needed to fix the measured object (irregular object) to establish a three-dimensional measurement coordinate system, so as to ensure the coincidence accuracy of the measurement coordinate origin, and accurately calculate the gravity coordinate value of the measured object (irregular object).

(3) According to the gravity center gravimetric measuring instrument, the high-precision pressure sensor is used for collecting pressure signals of irregular objects, the signals are conditioned through the instrument amplifier and the second-order low-pass filter, common-mode signals can be effectively inhibited, effective differential signals are amplified, the measuring precision is improved, and the effective measuring range is enlarged.

(4) According to the invention, the first sensor 9, the second sensor 10 and the third sensor 11 are simultaneously integrated on the same test bench 12, and a weight and gravity center measuring system is formed by the three pressure sensors for acquiring pressure data, the data acquisition board and the calculating mechanism, so that the gravity center and the weight of an irregular object can be rapidly and accurately measured.

Example 1

As shown in fig. 9, 11 and 12, the present embodiment provides a fixing tool 16 structure for fixing an irregular object (an object to be measured) on a supporting platform, where the fixing tool 16 includes a rectangular fixing base plate 5 and a fixing frame, the fixing frame is installed on the rectangular fixing base plate 5, and the fixing frame are perpendicular to each other; the fixed frame comprises a rectangular steel plate 6, a first right-angled triangular steel plate 7 and a second right-angled triangular steel plate 8; rectangular steel plate 6 locates a long edge of rectangle PMKD 5, and first right angle triangle-shaped steel sheet 7 and second right angle triangle-shaped steel sheet 8 locate two short edges of rectangle PMKD 5 respectively, and the right angle limit of first right angle triangle-shaped steel sheet 7 and second right angle triangle-shaped steel sheet 8 and rectangular steel plate 6 fixed connection.

In order to reduce the weight of the fixing tool 16, save the manufacturing material of the fixing tool 16 and save the manufacturing cost of the fixing tool 16, the first right-angled triangular steel plate 7 and the second right-angled triangular steel plate 8 both adopt hollow-out designs.

In order to further fix the irregular object, a plurality of locking assemblies are arranged on the fixing frame, the locking assemblies are arranged on the rectangular fixing bottom plate 5 and/or the rectangular steel plate 6 and/or the first right-angled triangular steel plate 7 and/or the second right-angled triangular steel plate 8, the locking assemblies all comprise fixing blocks 14 and locking blocks 15, the fixing blocks 14 and the locking blocks 15 are rectangular blocks, concave cavities are formed in the rectangular blocks, the fixing blocks 14 and the locking blocks 15 are butted together, and a space for accommodating a certain part of the irregular object is formed. In addition, a fixing block 14 in a locking assembly arranged on the rectangular fixing bottom plate 5 is welded with the rectangular fixing bottom plate 5, a locking block 15 and the fixing block 14 can be locked through a lock catch, and then an irregular object is fixed on the rectangular fixing bottom plate 5, when the fixing tool 16 is arranged on the bearing platform, a coordinate system (shown in fig. 9) on the fixing tool is overlapped with a coordinate system defined by the bearing platform, the fixing tool can ensure that the irregular object is in a static state, and when the irregular object is rotated, the fixing tool 16 rotates along with the irregular object and is relatively fixed between the irregular object and the bearing platform.

In the present application, a coordinate system of the fixing tool is defined, and the rectangular side of the first rectangular triangular steel plate 7 is taken as an x-axis, the long side of the rectangular steel plate 6 is taken as a y-axis, and the short side of the rectangular steel plate 6 is taken as a z-axis. The reason is that when the gravity center coordinate of the irregular object is measured, the irregular object needs to be rotated by 90 degrees clockwise along the ZOY plane, and the overturning angle can be ensured to be 90 degrees by defining the coordinate system of the fixed tool.

Example 2

As shown in fig. 10, the present embodiment provides a fixing tool 16 structure for fixing an irregular object (object to be measured) on a supporting platform, the fixing tool 16 includes a rectangular bottom plate 20 with a groove, a first guide fixing plate 17, a second guide fixing plate 18 and a third guide fixing plate 19 are disposed at an edge position on the rectangular bottom plate 20 with a groove, and the first guide fixing plate 17, the second guide fixing plate and the third guide fixing plate are perpendicular to the rectangular hollow bottom plate and are fixedly connected through pins.

It should be noted that, when the fixing tool 16 is fixed with the irregular object and then placed on the carrying platform, the first guide fixing plate 17 corresponds to the first vertical positioning plate 1 on the carrying platform, the second guide fixing plate 18 corresponds to the second vertical positioning plate 2 on the carrying platform, and the third guide fixing plate 19 corresponds to the third vertical positioning plate 3 on the carrying platform.

It should be noted that, the rectangular bottom plate 20 with the groove according to the present invention can reduce the weight of the fixing tool 16, and the groove formed according to the present invention can clamp and fix irregular objects.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims

1. A gravity center weight measurement system for irregular objects is characterized by comprising a test board and a computer which are connected through signals;

the test bench is used for realizing acquisition and sending of sensor data; and the computer is used for receiving the sensor data and calculating the weight and the gravity coordinate value of the irregular object according to the sensor data.

2. The system of claim 1, wherein the test platform comprises a load-bearing platform, a sensor and a data acquisition board;

the bearing platform is used for fixing the sensor and bearing the irregular object; the irregular object is fixed on the bearing platform through a fixing tool, and the sensor is used for acquiring the weight of the irregular object; the data acquisition board is used for controlling the analog-to-digital conversion to complete signal acquisition and sending an acquisition result to the computer.

3. The system for measuring the weight of the center of gravity of an irregular object according to claim 2, wherein a level gauge is arranged on the carrying platform and used for ensuring that the carrying platform is in a horizontal state;

a plurality of vertical positioning plates are arranged at the edge of the table top of the bearing platform and are used for ensuring that the fixing tool is placed along the edge of the bearing platform; the irregular object is fixed on the fixing tool;

the sensors include a first sensor, a second sensor, and a third sensor; the data acquisition board comprises an instrument amplifier, a filter, an A/D (analog/digital) conversion module, an MCU (micro control unit) and a serial port which are sequentially connected in a signal manner;

the A/D analog-to-digital conversion module is used for converting analog signals into digital signals, the MCU is used for receiving the digital signals, and the digital signals are transmitted to the computer through a serial port.

4. The system for measuring the weight of the center of gravity of an irregular object according to claim 3, wherein the fixing tool comprises a rectangular fixing bottom plate and a fixing frame, the fixing frame is arranged on the rectangular fixing bottom plate, and the fixing frame are arranged perpendicularly to each other;

the fixed frame comprises a rectangular steel plate, a first right-angled triangular steel plate and a second right-angled triangular steel plate; the rectangle steel sheet is located a long edge of rectangle PMKD, first right angle triangle-shaped steel sheet and second right angle triangle-shaped steel sheet are located two short edges of rectangle PMKD respectively, just the right angle limit of first right angle triangle-shaped steel sheet and second right angle triangle-shaped steel sheet with rectangle steel sheet fixed connection.

5. A gravity center weight measurement method for an irregular object, characterized by using the gravity center weight measurement system of claim 4, comprising the steps of:

step 1, defining a coordinate system of a bearing platform as O-XYZ; defining the barycentric coordinate of the irregular object as G (x0, y0, z 0); fixing the irregular object on the bearing platform through a fixing tool to enable the irregular object to be in a static state;

step 2, measuring the weight of the irregular object and the center of gravity component value of the X, Y axis;

and 4, analyzing and comparing the weight of the irregular object measured twice and the measurement precision of the X axis through a computer, and calculating the weight of the irregular object and XYZ barycentric coordinates according to a barycentric calculation principle.

6. The method according to claim 5, wherein in step 2, the weight of the irregular object is obtained by:

starting the weight and gravity center measuring system, wherein the supporting force of the irregular object measured by the first sensor is F1, the supporting force of the irregular object measured by the second sensor is F2, and the supporting force of the irregular object measured by the third sensor is F3; the weight of the irregular object is:

M*g＝F1+F2+F3 (1)

wherein M is the mass of the irregular object, g is the gravitational acceleration, and F1 is the supporting force provided by the first sensor; f2 is the supporting force provided by the second sensor; f3 is the support force provided by the third sensor.

7. The method as claimed in claim 6, wherein in the step 2, the system for measuring the gravity center of the irregular object is turned on, the pressure signals collected by the first sensor, the second sensor and the third sensor are processed by an instrumentation amplifier and a filter, the analog signals after being processed are converted into digital signals by an A/D analog-to-digital conversion module, and the digital signals are received by the MCU microcontroller and then transmitted to the computer for processing by a serial port, so as to obtain the supporting force F1 of the irregular object measured by the first sensor, the supporting force F2 of the irregular object measured by the second sensor and the supporting force F3 of the irregular object measured by the third sensor.

8. The gravity center weight measurement method for an irregular object according to claim 7, wherein in said step 2, said process of measuring the values of the gravity center components of the irregular object in the X-axis and the Y-axis is:

M*g*y0＝F1*Y1+F2*Y2+F3*Y3 (2)

M*g*x0＝F1*X1+F2*X2+F3*X3 (3)

x0＝(F1*X1+F2*X2+F3*X3)/M*g

y0＝(F1*Y1+F2*Y2+F3*Y3)/M*g

wherein M is the mass of the irregular object, g is the gravitational acceleration, F1 is the supporting force of the irregular object measured by the first sensor, F2 is the supporting force of the irregular object measured by the second sensor, F3 is the supporting force of the irregular object measured by the third sensor, and a (X1, Y1,0) is the coordinate of the first sensor; b (X2, Y2,0) is the coordinates of the second sensor; c (X3, Y3,0) is the coordinates of the third sensor.

9. The method according to claim 8, wherein in the step 3, the irregular object is rotated by 90 ° and then placed on the carrying platform, and the weight of the irregular object is measured again; the weight measurement process of the irregular object comprises the following steps:

M*g＝ F1'+ F2'+ F3' (1)

10. The gravity center weight measurement method for an irregular object according to claims 5 to 9, wherein in said step 3, after rotating the irregular object 90 ° clockwise along the ZOY plane, the abscissa of the gravity center position of the irregular object is x 0', the ordinate becomes the ordinate before the rotation, and said process of measuring the gravity center component value of X, Z axis is:

x0’＝(F1'*X1+F2'*X2+F3'*X3)/M*g；

z0＝(F1'*Y1+F2'*Y2+F3'*Y3)/M*g；