CN109870269B - Calibration method for three-dimensional force measuring platform - Google Patents
Calibration method for three-dimensional force measuring platform Download PDFInfo
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Abstract
The invention discloses a three-dimensional force measuring platform calibration method, which comprises the following steps: s1, calibrating a vertical force value; s2, calibrating a heading force value; s3, calibrating a lateral force value; s4, force value error and coupling error judgment. The invention solves the problem that a three-way force measuring platform for a drop test of an aviation industry landing gear company is difficult to systematically calibrate on a test site, and provides a calibration method for calibrating a large-tonnage three-way force measuring platform.
Description
Technical Field
The invention relates to the technical field of calibration of drop test equipment, in particular to a calibration method of a three-dimensional force measuring platform.
Background
During landing of an airplane and landing of a landing gear, generally, the tires of the airplane only bear normal forces in three directions, namely a heading direction (X direction), a lateral direction (Y direction) and a vertical direction (Z direction), which are applied by the ground. In the landing earthquake test for simulating the landing of the airplane, the three-way force measuring platform for testing the load of the landing gear also measures the normal force borne by the tire in three directions, namely the heading direction (X direction), the lateral direction (Y direction) and the vertical direction (Z direction) in the landing process of the simulated airplane. When the landing gear drop test of the airplane is carried out, only the loads in the X direction, the Y direction and the Z direction borne by the tire of the landing gear in the drop test process are accurately measured, the buffering and bearing characteristics of the tested landing gear can be really judged through calculation and analysis, and therefore the force value accuracy of the three-way force measuring platform needs to be subjected to system calibration judgment. The drop test result can be approved by the user only after the force measuring platform is measured or calibrated.
The three-way force measuring platform is a nonstandard device designed by each airline company, and generally comprises an upper table top, a lower table top and a three-way (vertical direction, course direction and lateral direction) force sensor assembly arranged between the upper table top and the lower table top. Three-way force platforms typically require 4 or 6 three-way force sensors. Namely, the vertical force value output of the force measuring platform is output by the vector sum of the vertical force values corresponding to the three-way sensors, the heading force value output of the force measuring platform is output by the vector sum of the heading force values corresponding to the three-way sensors, and the lateral force value output of the force measuring platform is output by the vector sum of the lateral force values corresponding to the three-way sensors; the heading and lateral force output of the three-way force measuring platform for the drop test is generally 1/3-1/2 of the vertical force value output. At present, a nonstandard equipment three-way force measuring platform for a drop test is not provided with a special measuring standard and a special measuring device in China, and the problem that a self-developed large-tonnage three-way force measuring platform of an aviation industry landing gear company is difficult to calibrate is always to be solved.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a three-way force measuring platform calibration method with high reliability and accuracy.
In order to solve the technical problems, the invention adopts the following technical scheme:
a calibration method of a three-way force measuring platform is characterized in that a rectangular coordinate system is established by taking the course stress of the three-way force measuring platform as the X direction, the lateral stress of the three-way force measuring platform as the Y direction and the vertical stress direction of the three-way force measuring platform as the Z direction, and comprises the following steps:
s1 vertical force value calibration
S1.1, loading standard vertical force to the three-way force measuring platform step by step along the Z direction, recording the actual vertical output force of the three-way force measuring platform, and recording a series set (Z1, Z2 … … Zm, … … Zn), wherein the numbers 1-n represent the series loaded step by step, Z represents the vertical direction, Zm represents the mth stage loaded vertically, and the standard vertical force set (F) is recordedZ1,FZ2……FZm……FZn) Wherein the numbers 1-n represent the number of stages loaded step by step, Z represents the vertical direction, F represents the normal force, FZmThe standard vertical force representing the loading of the m-th level, and the actual vertical output force set are recorded as (f)Z1,fZ2……fZm……fZn) Wherein the numbers 1-n represent the number of stages loaded step by step, Z represents the vertical direction, f represents the actual output forceZmThe actual vertical output force after the m-th level loading and the vertical force value error of the Zm-th level are shownZmThe calculation is as follows: (f)Zm-FZm)/FZ full rangeWherein F isZ full rangeThe standard vertical force of the full scale of the three-dimensional force measuring platform, and the error set of the vertical force value is recorded as (A)Z1,Z2……Zm……Zn) Wherein the numbers 1-n represent the number of stages loaded step by step, Z represents the vertical direction and is an error code,Zmrepresenting the vertical force value error of the mth level; if the absolute value of the vertical force value error of each stage is less than or equal to the set vertical force value error, turning to step S2; if the absolute value of the vertical force value error of at least one stage is larger than the set vertical force value error, the step S1.2 is carried out;
s1.2 with (1-Zmax) As a correction coefficient, multiplying the force value of each measuring point of a vertical force value calibration curve corresponding to each three-way force sensor in the software of the upper computer of the three-way force measuring platform by the correction coefficient, and re-fitting to obtain a corrected force valueFitting a curve vertically; wherein,Zmaxthe vertical force value error with the largest absolute value in the vertical force value error set is obtained;
s2 calibration of heading force value
S2.1, loading pre-pressure to the three-way force measuring platform along the Z direction;
s2.2, loading a standard course force to the three-way force measuring platform step by step along the X direction, and turning to the step S2.3 if the error between the actual vertical output force and the pre-pressure is less than or equal to a set interference error; if the error between the actual vertical output force and the pre-pressing force is more than the set interference error, judging that the vertical output force is unqualified;
s2.3, recording the actual course output force of the three-way force measuring platform, and recording a series set as (X1, X2 … … Xm, … … Xn), wherein the numbers 1-n represent the series loaded step by step, X represents the course direction, Xm represents the mth stage loaded by the course, and a standard course force set is (F)X1,FX2……FXm……FXn) Wherein the numbers 1-n represent the number of stages loaded step by step, X represents the heading force direction, F represents the standard force, FXmThe standard course force of the m-th level loading is represented, and the set of the actual course output force is recorded as (f)X1,fX2……fXm……fXn) Wherein the numbers 1-n represent the number of stages loaded step by step, X represents the heading force direction, f represents the actual output forceXmRepresenting the actual course output force after the mth level loading and the course force value error of the Xm levelXmThe calculation is as follows: (f)Xm–FXm)/FX full rangeWherein F isX full rangeThe standard course force of the full scale of the three-way force measuring platform, and the error set of the course force value is recorded as (A)X1,X2……Xm……Xn) Wherein the numbers 1-n represent the stage number loaded stage by stage, X represents the direction of course force and is an error code,Xmrepresenting the error of the heading force value of the mth level; if the absolute value error of the heading force value of each stage is less than or equal to the set heading force value error, turning to the step S3; if the absolute value of the error of the heading force value of at least one stage is larger than the error of the set heading force value, turning to the step S2.4;
s2.4 with (1-Xmax) As a correction coefficient, the three-dimensional force measuring platform is arranged onMultiplying the force value of each metering point of a course force value calibration curve corresponding to each three-way force sensor in the computer software by the correction coefficient, and re-fitting to obtain a corrected course fitting curve; wherein,Xmaxthe absolute value of the error is the largest course force value error in the course force value error set;
s3, calibrating lateral force value
S3.1, loading pre-pressure to the three-way force measuring platform along the Z direction;
s3.2, loading standard lateral force to the three-way force measuring platform step by step along the Y direction, and turning to the step S3.3 if the error between the actual vertical output force and the pre-pressure is less than or equal to a set interference error; if the error between the actual vertical output force and the pre-pressing force is more than the set interference error, judging that the vertical output force is unqualified;
s3.3, recording the actual lateral output force of the three-way force measuring platform, and recording the set of the stages as (Y1, Y2 … … Ym, … … Yn), wherein the numbers 1-n represent the stages loaded step by step, Y represents the lateral direction, Ym represents the mth stage loaded laterally, and the set of the standard lateral force is (F)Y1,FY2……FYm……FYn) Wherein the numbers 1-n represent the number of steps of the stepwise loading, Y represents the direction of the lateral force, F represents the normal force, FYmThe standard lateral force of the loading of the m-th stage is shown, and the set of the actual lateral output force is (f)Y1,fY2……fYm……fYn) Wherein the numbers 1-n represent the number of steps of the stepwise loading, Y represents the direction of the lateral force, f represents the actual output force, fYmRepresenting the actual lateral output force after the m-th level loading and the lateral force value error of the Ym-th levelYmThe calculation is as follows: (f)Ym–FYm)/FY full scaleWherein F isY full scaleThe error set of the lateral force value is the standard lateral force of the full scale of the three-dimensional force measuring platform and is recorded as (Y1,Y2……Ym……Yn) Wherein the numbers 1-n represent the number of stages loaded step by step, Y represents the direction of the lateral force and is an error code,Ymrepresenting the lateral force value error of the mth order; if the absolute value of the lateral force value error of each stage is less than or equal to the set lateral force value error, turning to step S4; if there is at least one absolute value of lateral force value errorSetting the error of the lateral force value for more than ten, and turning to the step S3.4;
s3.4 with (1-Ymax) Taking the force values of all metering points of a lateral force value calibration curve corresponding to each three-way force sensor in the three-way force measuring platform upper computer software as correction coefficients, multiplying the correction coefficients by the force values of all metering points, and re-fitting to obtain corrected lateral fitting curves; wherein,Ymaxthe lateral force value error with the maximum absolute value in the lateral force value error set is obtained;
s4, force value error and coupling error judgment
Step-by-step loading standard vertical force to the three-way force measuring platform along the Z direction, and recording output force values in the Z direction, the X direction and the Y direction; calculating the force value error in the Z direction and the force value coupling error of the Z direction to the X direction and the Y direction respectively;
step-by-step loading standard course force to the three-way force measuring platform along the X direction, and recording output force values in the Z direction, the X direction and the Y direction; calculating the force value error in the X direction and the force value coupling error of the X direction to the Z direction and the Y direction respectively;
step-by-step loading standard lateral force to the three-way force measuring platform along the Y direction, and recording output force values in the Z direction, the X direction and the Y direction; calculating a force value error in the Y direction and force value coupling errors of the Y direction to the X direction and the Z direction respectively;
if the absolute value of each force value error is less than the set force value error and the absolute value of each force value coupling error is less than the set coupling error, judging that the product is qualified; and if the absolute value of at least one force value error is larger than the set force value error and/or the absolute value of at least one force value coupling error is larger than the set coupling error, judging that the device is unqualified.
Practice shows that the direction of the three-way force applied to the force measuring platform by the tire of the landing gear in the test process is determined, the nonstandard three-way force measuring platform is taken as a standard three-way force sensor after being installed in place according to the specified bearing stress direction, and the method for calibrating the force value system by respectively applying standard static force step by step in the three bearing stress directions is feasible. The measurement accuracy of the force in a single direction can be affected by the rigidity of the table top, the assembly clearance of a plurality of sensors and the like, and due to the limitation of the preparation technology, coupling errors can exist among the force values in the three directions.
In the exploration of the force value calibration method, according to a conventional thought, the applicant uses a three-way force sensor to measure discrete point values in a certain direction to fit corresponding direction software channels in the three-way force platform upper computer software into a calibration curve, and multiplies different correction factors on different discrete points, so that on the surface, each discrete point is calibrated in a qualified error range, the linear relation of the measuring sensor is not followed substantially, and the calibration precision between two adjacent discrete points cannot be guaranteed. The result is qualified when the data is separated from each discrete point in calibration, the deviation between the integral power quantity of the vertical force and the displacement tested in a specific test and the theoretical power quantity numerical value is large, the deviation between the integral power quantity and the theoretical input power quantity is also large, the dynamic force value test is inaccurate through the investigation and analysis of reasons, the multiplication of different correction factors on each discrete point is not correct, the linear relation of the original sensor is not followed, and the numerical precision between two calibration discrete points cannot be ensured.
Subsequent studies by the applicant show that when the three-way force sensor is calibrated in a single direction, namely discrete points, linearity, errors, hysteresis and the like are all indexes, and therefore, the metering linear relation of the single sensor also needs to be followed when the force measuring platform is calibrated. The force table is designed according to the installation and use requirements of the sensor. At present, according to a common factor method, each discrete point is multiplied by the same scale factor within an error allowable range, the linear relation of a sensor is followed, the force value precision is accurately evaluated within a full-range, the measured force value is more accurate, and the test work amount, the theoretical work amount and the input work amount are more consistent in a specific test and are also within a tolerance allowable range.
In the above three-way force measuring platform calibration method, preferably, the step S1 includes the following steps:
s1.3, loading the standard course force to the three-way force measuring platform step by step along the Z direction, and repeating the step S1.1 until the absolute value of the vertical force value error of each stage is less than or equal to the set vertical force value error.
In the above three-way force measuring platform calibration method, preferably, the step S2 includes the following steps:
s2.5, loading the standard course force to the three-way force measuring platform step by step along the X direction, and repeating the step S2.3 until the absolute value of the course force value error of each stage is less than or equal to the set course force value error.
In the above three-way force measuring platform calibration method, preferably, the step S3 includes the following steps:
and S3.5, loading the standard lateral force to the three-way force measuring platform step by step along the Y direction, and repeating the step S3.3 until the absolute value of the lateral force value error of each stage is less than or equal to the set lateral force value error.
In the calibration method for the three-dimensional force measuring platform, preferably, the force value error in a certain direction is defined as: force value error ═ (calibration direction output force value-calibration direction standard force value)/calibration direction standard force value, or: the force value error is (the force value output in the calibration direction of the force measuring platform-the standard force value in the calibration direction of the force measuring platform)/the standard force value in the full scale of the calibration direction of the force measuring platform.
In the above calibration method for a three-dimensional force measuring platform, preferably, the coupling error in one direction to another direction is defined as: and when the load is loaded in one direction, the maximum output force value in the other direction/the full-scale value in the other direction.
In the calibration method of the three-way force measuring platform, preferably, the pre-pressure is a full-scale value or a half of the full-scale value of the vertical output force of the three-way force measuring platform.
Preferably, in the calibration method for the three-dimensional force measuring platform, the step-by-step loading mode is as follows: the number of the equal difference series is gradually increased in the range of the measuring range.
Preferably, in the calibration method for the three-way force measuring platform, the error of the set vertical force value, the error of the set heading force value and the error of the set lateral force value are 1%, the error of the set interference is 3%, and the error of the set coupling is 3%.
In the calibration method of the three-way force measuring platform, preferably, the position where the three-way force measuring platform loads the standard vertical force is the position of the drop point of the tested piece; the position of the three-way force measuring platform for loading the standard course force is the central position of a certain side surface of the three-way force measuring platform along the course direction; the position of the three-way force measuring platform for loading the standard lateral force is the central position of a certain side surface of the three-way force measuring platform along the lateral direction.
Practice shows that the vertical force value (Z direction) is influenced by the change of the stiffness of the table top after the force measuring platform bears load vertically (Z direction), and the vertical force area of the force measuring platform is limited to be calibrated according to the position of a tire drop point during calibration.
Compared with the prior art, the invention has the advantages that:
the invention solves the problem that a three-way force measuring platform for a drop test of an aviation industry landing gear company is difficult to systematically calibrate on a test site, and provides a calibration method for calibrating a large-tonnage three-way force measuring platform. The three-way force measuring platform calibrated by the method is applied to a plurality of landing gear drop tests of military and civil aircrafts, and is popular with users.
Drawings
Fig. 1 is a schematic perspective view of a three-dimensional force measuring platform calibration system according to an embodiment of the present invention.
Fig. 2 is a schematic structural view of a three-way force measuring platform calibration system according to an embodiment of the present invention.
Fig. 3 is a schematic perspective view of another perspective view of a three-way force measuring platform calibration system according to an embodiment of the present invention.
Fig. 4 is a schematic structural diagram of an anti-unbalanced loading mechanism in the embodiment of the invention.
Fig. 5 is a sectional view a-a of fig. 4.
FIG. 6 is a diagram of a hydraulic loading system of a loading cylinder in a calibration system according to an embodiment of the present invention.
Detailed Description
The invention is further described below with reference to specific preferred embodiments, without thereby limiting the scope of protection of the invention.
Example 1:
the present embodiment uses a three-way force platform calibration system as shown in figures 1-3 to calibrate a three-way force platform for landing gear drop tests. The three-way force measuring platform calibration system comprises a calibration platform 1, and a vertical loading mechanism 2, a course loading mechanism 3 and a lateral loading mechanism 4 which are arranged on the calibration platform 1. Wherein, a plurality of T-shaped grooves 11 arranged at intervals along the X direction are arranged on the calibration platform 1.
The three-way force measuring platform 5 is horizontally arranged on the calibration platform 1, a rectangular coordinate system is established by taking the course stress of the three-way force measuring platform 5 as the X direction, the lateral stress of the three-way force measuring platform 5 as the Y direction and the vertical stress direction of the three-way force measuring platform 5 as the Z direction, and the vertical loading mechanism 2 is used for providing a vertical standard force to the three-way force measuring platform 5 along the Z direction; the course loading mechanism 3 is used for providing course standard force to the three-way force measuring platform 5 along the X direction; the lateral loading mechanism 4 is used to provide a lateral standard force to the three-way force platform 5 along the Y direction.
In this embodiment, the vertical loading mechanism 2 includes the vertical mounting bracket 21 fixed on the calibration platform 1, the vertical mounting bracket 21 includes a cross beam 211 and two columns 212, the two columns 212 are respectively disposed on two sides of the three-way force measuring platform 5 along the Y direction, and the cross beam 211 is fixed on the upper ends of the two columns 212.
The bottom surface of the cross beam 211 is sequentially connected with a vertical hydraulic loading cylinder 22 for loading vertical standard force to the three-way force measuring platform 5, a vertical force measuring sensor 23 for measuring vertical standard force, and an anti-unbalance loading mechanism 6 for preventing the standard vertical force from deviating from the direction and loading the standard vertical force to other two directions along the Z direction.
In this embodiment, the heading loading mechanism 3 includes a heading mounting bracket 31 fixed on the calibration platform 1, and a heading hydraulic loading cylinder 32 for loading a heading standard force to the three-way force measuring platform 5, a heading force measuring sensor 33 for measuring the heading standard force, and an anti-unbalance loading mechanism 6 for preventing the standard heading force from deviating from the direction and loading the standard heading force to other two directions are sequentially connected to the heading mounting bracket 31 along the X direction.
In this embodiment, the lateral loading mechanism 4 includes a lateral mounting bracket 41 fixed on the calibration platform 1, and a lateral hydraulic loading cylinder 42 for loading a lateral standard force to the three-way load cell platform 5, a lateral load cell 43 for measuring the lateral standard force, and an anti-unbalance loading mechanism 6 for preventing the standard lateral force from being loaded to other two directions when the standard lateral force deviates from the direction are sequentially connected to the lateral mounting bracket 41 along the Y direction.
As shown in fig. 4 to 5, the anti-unbalance loading mechanism 6 includes a first plate 61 and a second plate 62, and balls 63 interposed between the first plate 61 and the second plate 62; in the anti-unbalance mechanism 6 in a certain direction, the first plate 61 and the second plate 62 are perpendicular to the direction.
The first 61 and second 62 plates are preferably discs sized according to the test landing gear tire size, the discs define a range of standard force application for the force platform, the balls 63 apply force in a direction perpendicular to the discs, and the remaining degrees of freedom are released. When the three direction force values are calibrated, even if an included angle is generated between the standard force applied to the force measuring platform and the design stress direction of the force measuring platform due to the deformation of the clamp or the deformation of the force platform, the standard force value cannot be added to the other two direction output values of the force measuring platform, the effect of resisting the deviation of the additional force value is achieved, and the calibration precision is improved.
The upright 212, the heading mounting frame 31, the lateral mounting frame 41 and the three-way force measuring platform 5 are all fixed on the calibration platform 1 through the matching of T-shaped bolts and T-shaped grooves 11.
Fig. 6 shows a hydraulic loading device 7 of each loading hydraulic cylinder, which comprises a hand pump 71, an oil filter 72, a one-way valve 73, a switch 1, a switch 2, a switch 3, a switch 4, a hose 74, a quick-change connector 75, a loading hydraulic cylinder 76 and a hydraulic control one-way valve 77. And (3) turning on the switches 1 and 4, turning off the switches 2 and 3, shaking the hand pump 71, and moving the hydraulic loading cylinder 76 downwards to apply standard force to the force measuring platform until the standard force is applied to the required value, and stopping and locking with load. When the hydraulic loading cylinder 76 retracts to move upwards, the switches 2 and 3 are turned on, the switches 1 and 4 are turned off, and the hand-cranking pump 71 is shaken, so that the standard force applied by the upward movement and the unloading of the hydraulic loading cylinder 76 can be realized.
The invention comprises the following steps:
before calibration, all three-way force sensors are input into a three-way force measuring platform software channel and correspond to vertical, course and lateral standard metering values, and a force value calibration curve is fitted (y is kx + b, y is a force value, and x is a voltage value).
S1 vertical force value calibration
S1.1, gradually loading 6-8 levels of standard vertical force to the three-way force measuring platform along the Z direction, wherein the position for loading the standard vertical force is the position of a tested piece drop point as shown in figure 1; and during calibration, a vertical stress area of the force measuring platform is limited to calibrate according to the position of the tire drop point. After each loading for 10 seconds, recording the actual vertical output force of the upper computer of the three-way force measuring platform, recording the series set as (Z1, Z2 … … Zm, … … Zn), and recording the standard vertical force set as (F)Z1,FZ2……FZm……FZn) The set of actual vertical output forces is denoted as (f)Z1,fZ2……fZm……fZn) Vertical force error of Zm-th orderZmThe calculation is as follows: (f)Zm-FZm)/FZ full rangeThe error set of vertical force values is given asZ1,Z2……Zm……Zn) Wherein F isZ full rangeThe standard vertical force is the full range of the three-dimensional force measuring platform; if the absolute value of the vertical force value error of each stage is less than or equal to 1% after two continuous cycles, turning to step S2; if the absolute value of the error of the vertical force value of at least one stage is more than 1 percent, turning to the step S1.2;
in actual operation, the calibration value is generally according to the home position ((f)Zm-FZm)/FZm) Firstly, calculating that the linearity of the force measuring platform is good when the home position calibration values are all within 1 percent, and directly turning to the step S1.2.
S1.2 with (1-Zmax) Taking the force values of all metering points of a vertical force value calibration curve of each three-way force sensor in the three-way force measuring platform upper computer software as a correction coefficient, multiplying the correction coefficient by the force values of all metering points, and re-fitting to obtain a corrected vertical fitting curve; wherein,Zmaxthe vertical force value error with the largest absolute value in the vertical force value error set is obtained;
s1.3, repeating the step S1.1 until the absolute value of the vertical force value error of each stage is less than or equal to 1 percent. Generally, 2-3 times of channel check is carried out, and the error of the force value can be controlled within +/-1%.
S2 calibration of heading force value
And S2.1, loading pre-pressure to the three-way force measuring platform along the Z direction, wherein the pre-pressure is generally half of a full-scale value of the vertical output force of the three-way force measuring platform.
And S2.2, loading 6-8 levels of standard course force to the three-way force measuring platform step by step along the X direction, wherein the position for loading the standard course force is the central position of a certain side surface of the three-way force measuring platform along the course direction as shown in the figure 1. If the error between the actual vertical output force and the pre-pressure is less than or equal to 3 percent, turning to the step S2.3; if the error between the actual vertical output force and the pre-pressing force is more than 3 percent, judging that the vertical output force is unqualified;
s2.3, recording the actual heading output force of the three-way force measuring platform after each loading for 10 seconds, recording the series aggregate as (X1, X2 … … Xm, … … Xn), and recording the standard heading force aggregate as (F)X1,FX2……FXm……FXn) The set of actual heading output forces is recorded as (f)X1,fX2……fXm……fXn) Xm th order heading force errorXmThe calculation is as follows: (f)Xm–FXm)/FX full rangeThe error set of heading force values is given asX1,X2……Xm……Xn) Wherein F isX full rangeThe standard course force is the full range of the three-dimensional force measuring platform; if the absolute value of the heading force value error of each stage after two continuous cyclic loading is less than or equal to 1%, turning to step S3; if the absolute value of the error of the heading force value of at least one stage is more than 1%, turning to the step S2.4;
s2.4 with (1-Xmax) Taking the force values of all measuring points of a three-way force sensor heading force value calibration curve in the three-way force measuring platform software as correction coefficients, multiplying the correction coefficients by the force values of all measuring points, and re-fitting to obtain a corrected heading fitting curve; wherein,Xmaxthe absolute value of the error is the largest course force value error in the course force value error set;
s2.5, loading the standard course force to the three-way force measuring platform step by step along the X direction, and repeating the step S2.3 until the absolute value of the error of the course force value of each stage is less than or equal to 1%. Generally, 2-3 times of channel check is carried out, and the error of the force value can be controlled within +/-1%.
S3, calibrating lateral force value
S3.1, loading pre-pressure to the three-way force measuring platform along the Z direction;
and S3.2, gradually loading 6-8 levels of standard lateral force to the three-way force measuring platform along the Y direction, wherein the position for loading the standard lateral force is the central position of a certain side surface of the three-way force measuring platform along the lateral direction. If the error between the actual vertical output force and the pre-pressure is less than or equal to 3 percent, turning to the step S3.3; if the error between the actual vertical output force and the pre-pressing force is more than 3 percent, judging that the vertical output force is unqualified;
s3.3, recording the actual lateral output force of the three-way force measuring platform, wherein the set of the series is (Y1, Y2 … … Ym, … … Yn), and the set of the standard lateral force is (F)Y1,FY2……FYm……FYn) The actual lateral output force set is denoted as (f)Y1,fY2……fYm……fYn) Error of lateral force value of Ym orderYmThe calculation is as follows: (f)Ym–FYm)/FY full scaleError set of lateral force values is given byY1,Y2……Ym……Yn) Wherein F isY full scaleThe standard lateral force is the full range of the three-dimensional force measuring platform; if the absolute value of the error of the lateral force value of each stage after continuous two-cycle loading is less than or equal to 1%, turning to step S4; if the absolute value of the error of the lateral force value of at least one stage is more than 1%, turning to the step S3.4;
s3.4 with (1-Ymax) Taking the force values of all measuring points of a lateral force value calibration curve of each three-way force sensor in the three-way force measuring platform software as correction coefficients, multiplying the correction coefficients by the force values of all measuring points, and re-fitting to obtain corrected lateral fitting curves; wherein,Ymaxthe lateral force value error with the maximum absolute value in the lateral force value error set is obtained;
and S3.5, loading the standard lateral force to the three-way force measuring platform step by step along the Y direction, and repeating the step S3.3 until the absolute value of the error of the lateral force value of each stage is less than or equal to 1%. Generally, 2-3 times of channel check is carried out, and the error of the force value can be controlled within +/-1%.
S4, force value error and coupling error judgment
Step-by-step loading 6-8 standard vertical forces to the three-way force measuring platform along the Z direction, and recording output force values in the Z direction, the X direction and the Y direction; calculating the force value error in the Z direction and the coupling force value error of the Z direction to the X direction and the Y direction respectively;
step-by-step loading 6-8 standard course forces to the three-way force measuring platform along the X direction, and recording output force values in the Z direction, the X direction and the Y direction; calculating the force value error in the X direction and the coupling force value error in the X direction to the Z direction and the Y direction respectively;
step-by-step loading 6-8 standard lateral forces to the three-way force measuring platform along the Y direction, and recording output force values in the Z direction, the X direction and the Y direction; calculating the force value error in the Y direction and the coupling force value error of the Y direction to the X direction and the Z direction respectively;
if the absolute value of each force value error is less than the set force value error and the absolute value of each coupling force value error is less than the set coupling force value error, judging that the product is qualified; and if the absolute value of at least one force value error is larger than the set force value error and/or the absolute value of at least one coupling force value error is larger than the set coupling error, determining that the coupling error is unqualified.
Wherein, the force value error of a certain direction of the three-way force measuring platform is defined as: force value error (force value output by force platform calibration direction-force platform calibration direction standard force value)/force platform calibration direction standard force value, or: the force value error is (the force value output in the calibration direction of the force measuring platform-the standard force value in the calibration direction of the force measuring platform)/the standard force value in the full scale of the calibration direction of the force measuring platform.
The coupling error from one direction to the other is defined as: when loading is carried out in one direction, the maximum output force value in the other direction/the full-scale value in the other direction, or:
the following is a measurement example of a non-standard three-way force measuring platform applied to a certain airline company by applying the invention:
the data for step S1.1 are shown in table 1:
TABLE 1
Note: and adding standard forces of 100KN and 200KN … … 700KN, and because the loading equipment is not in automatic closed-loop control, each time of adding force is near 100KN and 200KN … … 700KN, judging that the integer value stops loading, waiting for 5 minutes, and reading again after the value is stable. The data read is not the same each time it is loaded near an integer value.
As can be seen from Table 1, the vertical force error with the largest absolute value in the set of vertical force errorsZmaxAnd the standard measuring force value of each three-way force sensor vertical force value calibration curve in the three-way force measuring platform software is multiplied by the correction coefficient by taking (1-1.51%) as the correction coefficient, and the corrected vertical force value calibration curve is obtained after refitting. After repeated checking, the absolute value of the error of each vertical force value is within 1 percent.
S2, displaying the result that the error of each heading force value is within 1%; the result of step S3 shows that the error of each lateral force value is within 1%.
The data of step S4 is shown in table 2:
TABLE 2
Note: in this table, the force value error is (force value output in the calibration direction of the force platform-force platform calibration direction standard force value)/force value at full scale in the calibration direction of the force platform.
The above description is only for the preferred embodiment of the present application and should not be taken as limiting the present application in any way, and although the present application has been disclosed in the preferred embodiment, it is not intended to limit the present application, and those skilled in the art should understand that they can make various changes and modifications within the technical scope of the present application without departing from the scope of the present application, and therefore all the changes and modifications can be made within the technical scope of the present application.
Claims (9)
1. A calibration method of a three-way force measuring platform is characterized by establishing a rectangular coordinate system by taking the course stress of the three-way force measuring platform as an X direction, the lateral stress of the three-way force measuring platform as a Y direction and the vertical stress direction of the three-way force measuring platform as a Z direction, and comprises the following steps:
s1 vertical force value calibration
S1.1, loading standard vertical force to the three-way force measuring platform step by step along the Z direction, recording the actual vertical output force of the three-way force measuring platform, and recording a series set (Z1, Z2 … … Zm, … … Zn), wherein the numbers 1-n represent the series loaded step by step, Z represents the vertical direction, Zm represents the mth stage loaded vertically, and the standard vertical force set (F) is recordedZ1,FZ2……FZm……FZn) Wherein the numbers 1-n represent the number of stages loaded step by step, Z represents the vertical direction, F represents the normal force, FZmThe standard vertical force representing the loading of the m-th level, and the actual vertical output force set are recorded as (f)Z1,fZ2……fZm……fZn) Wherein the numbers 1-n represent the number of stages loaded step by step, Z represents the vertical direction, f represents the actual output forceZmThe actual vertical output force after the m-th level loading and the vertical force value error of the Zm-th level are shownZmThe calculation is as follows: (f)Zm-FZm)/FZ full rangeWherein F isZ full rangeThe standard vertical force of the full scale of the three-dimensional force measuring platform, and the error set of the vertical force value is recorded as (A)Z1,Z2……Zm……Zn) Wherein the numbers 1-n represent the number of stages loaded step by step, Z represents the vertical direction and is an error code,Zmrepresenting the vertical force value error of the mth level; if the absolute value of the vertical force value error of each stage is less than or equal to the set vertical force value error, turning to step S2; if the absolute value of the vertical force value error of at least one stage is larger than the set vertical force value error, the step S1.2 is carried out;
s1.2 with (1-Zmax) As a correction coefficient, multiplying the force value of each measuring point of a vertical force value calibration curve corresponding to each three-way force sensor in the software of the upper computer of the three-way force measuring platform by the correction coefficient, and re-simulatingObtaining a corrected vertical fitting curve after combination; wherein,Zmaxthe vertical force value error with the largest absolute value in the vertical force value error set is obtained;
s2 calibration of heading force value
S2.1, loading pre-pressure to the three-way force measuring platform along the Z direction;
s2.2, loading a standard course force to the three-way force measuring platform step by step along the X direction, and turning to the step S2.3 if the error between the actual vertical output force and the pre-pressure is less than or equal to a set interference error; if the error between the actual vertical output force and the pre-pressing force is more than the set interference error, judging that the vertical output force is unqualified;
s2.3, recording the actual course output force of the three-way force measuring platform, and recording a series set as (X1, X2 … … Xm, … … Xn), wherein the numbers 1-n represent the series loaded step by step, X represents the course direction, Xm represents the mth stage loaded by the course, and a standard course force set is (F)X1,FX2……FXm……FXn) Wherein the numbers 1-n represent the number of stages loaded step by step, X represents the heading force direction, F represents the standard force, FXmThe standard course force of the m-th level loading is represented, and the set of the actual course output force is recorded as (f)X1,fX2……fXm……fXn) Wherein the numbers 1-n represent the number of stages loaded step by step, X represents the heading force direction, f represents the actual output forceXmRepresenting the actual course output force after the mth level loading and the course force value error of the Xm levelXmThe calculation is as follows: (f)Xm–FXm)/FX full rangeWherein F isX full rangeThe standard course force of the full scale of the three-way force measuring platform, and the error set of the course force value is recorded as (A)X1,X2……Xm……Xn) Wherein the numbers 1-n represent the stage number loaded stage by stage, X represents the direction of course force and is an error code,Xmrepresenting the error of the heading force value of the mth level; if the absolute value error of the heading force value of each stage is less than or equal to the set heading force value error, turning to the step S3; if the absolute value of the error of the heading force value of at least one stage is larger than the error of the set heading force value, turning to the step S2.4;
s2.4 with (1-Xmax) As a correction factor, measure three directionsMultiplying the force value of each metering point of a course force value calibration curve corresponding to each three-way force sensor in the force platform upper computer software by the correction coefficient, and re-fitting to obtain a corrected course fitting curve; wherein,Xmaxthe absolute value of the error is the largest course force value error in the course force value error set;
s3, calibrating lateral force value
S3.1, loading pre-pressure to the three-way force measuring platform along the Z direction;
s3.2, loading standard lateral force to the three-way force measuring platform step by step along the Y direction, and turning to the step S3.3 if the error between the actual vertical output force and the pre-pressure is less than or equal to a set interference error; if the error between the actual vertical output force and the pre-pressing force is more than the set interference error, judging that the vertical output force is unqualified;
s3.3, recording the actual lateral output force of the three-way force measuring platform, and recording the set of the stages as (Y1, Y2 … … Ym, … … Yn), wherein the numbers 1-n represent the stages loaded step by step, Y represents the lateral direction, Ym represents the mth stage loaded laterally, and the set of the standard lateral force is (F)Y1,FY2……FYm……FYn) Wherein the numbers 1-n represent the number of steps of the stepwise loading, Y represents the direction of the lateral force, F represents the normal force, FYmThe standard lateral force of the loading of the m-th stage is shown, and the set of the actual lateral output force is (f)Y1,fY2……fYm……fYn) Wherein the numbers 1-n represent the number of steps of the stepwise loading, Y represents the direction of the lateral force, f represents the actual output force, fYmRepresenting the actual lateral output force after the m-th level loading and the lateral force value error of the Ym-th levelYmThe calculation is as follows: (f)Ym–FYm)/FY full scaleWherein F isY full scaleThe error set of the lateral force value is the standard lateral force of the full scale of the three-dimensional force measuring platform and is recorded as (Y1,Y2……Ym……Yn) Wherein the numbers 1-n represent the number of stages loaded step by step, Y represents the direction of the lateral force and is an error code,Ymrepresenting the lateral force value error of the mth order; if the absolute value of the lateral force value error of each stage is less than or equal to the set lateral force value error, turning to step S4; if there is at least one lateral force errorSetting a lateral force value error for the value more than, and turning to the step S3.4;
s3.4 with (1-Ymax) Taking the force values of all metering points of a lateral force value calibration curve corresponding to each three-way force sensor in the three-way force measuring platform upper computer software as correction coefficients, multiplying the correction coefficients by the force values of all metering points, and re-fitting to obtain corrected lateral fitting curves; wherein,Ymaxthe lateral force value error with the maximum absolute value in the lateral force value error set is obtained;
s4, force value error and coupling error judgment
Step-by-step loading standard vertical force to the three-way force measuring platform along the Z direction, and recording output force values in the Z direction, the X direction and the Y direction; calculating the force value error in the Z direction and the force value coupling error of the Z direction to the X direction and the Y direction respectively;
step-by-step loading standard course force to the three-way force measuring platform along the X direction, and recording output force values in the Z direction, the X direction and the Y direction; calculating the force value error in the X direction and the force value coupling error of the X direction to the Z direction and the Y direction respectively;
step-by-step loading standard lateral force to the three-way force measuring platform along the Y direction, and recording output force values in the Z direction, the X direction and the Y direction; calculating a force value error in the Y direction and force value coupling errors of the Y direction to the X direction and the Z direction respectively;
if the absolute value of each force value error is less than the set force value error and the absolute value of each force value coupling error is less than the set coupling error, judging that the product is qualified; and if the absolute value of at least one force value error is larger than the set force value error and/or the absolute value of at least one force value coupling error is larger than the set coupling error, judging that the device is unqualified.
2. The method of calibrating a three-way load cell platform of claim 1, wherein said step S1 comprises the steps of:
s1.3, loading the standard course force to the three-way force measuring platform step by step along the Z direction, and repeating the step S1.1 until the absolute value of the vertical force value error of each stage is less than or equal to the set vertical force value error.
3. The method of calibrating a three-way load cell platform of claim 1, wherein said step S2 comprises the steps of:
s2.5, loading the standard course force to the three-way force measuring platform step by step along the X direction, and repeating the step S2.3 until the absolute value of the course force value error of each stage is less than or equal to the set course force value error.
4. The method of calibrating a three-way load cell platform of claim 1, wherein said step S3 comprises the steps of:
and S3.5, loading the standard lateral force to the three-way force measuring platform step by step along the Y direction, and repeating the step S3.3 until the absolute value of the lateral force value error of each stage is less than or equal to the set lateral force value error.
5. The method for calibrating a three-way force measuring platform according to any one of claims 1 to 4, wherein the force value error in a certain direction is defined as: the coupling error from one direction to the other is defined as: and when the load is loaded in one direction, the maximum output force value in the other direction/the full-scale value in the other direction.
6. The method for calibrating a three-way force measuring platform according to any one of claims 1 to 4, wherein the pre-pressure is the full-scale value or half of the full-scale value of the vertical output force of the three-way force measuring platform.
7. A method for calibrating a three-way force measuring platform according to any one of claims 1 to 4, wherein the stepwise loading is performed by: the number of the equal difference series is gradually increased in the range of the measuring range.
8. The method for calibrating a three-way force measuring platform according to any one of claims 1 to 4, wherein the set vertical force value error, the set heading force value error and the set lateral force value error are 1%, the set disturbance error is 3% and the set coupling error is 3%.
9. The method for calibrating a three-way force measuring platform according to any one of claims 1 to 4, wherein the position of the three-way force measuring platform loaded with the standard vertical force is a position of a drop point of a tested piece; the position of the three-way force measuring platform for loading the standard course force is the central position of a certain side surface of the three-way force measuring platform along the course direction; the position of the three-way force measuring platform for loading the standard lateral force is the central position of a certain side surface of the three-way force measuring platform along the lateral direction.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5020357A (en) * | 1989-08-18 | 1991-06-04 | N. K. Biotechnical Engineering Company | Calibration stand for sensor |
| CN102135461A (en) * | 2010-12-14 | 2011-07-27 | 西北工业大学 | Undercarriage load calibration device and method for calibrating load of undercarriage by using device |
| CN102692319A (en) * | 2012-06-12 | 2012-09-26 | 西南交通大学 | Passive follow-up force-applied linear guiderail pair test bed with controllable load |
| CN103196629A (en) * | 2013-03-30 | 2013-07-10 | 大连交通大学 | Six-dimensional sensor calibration device |
| CN103604561A (en) * | 2013-11-27 | 2014-02-26 | 东南大学 | Calibration device and method of six-axis force/torque sensor |
| CN107621422A (en) * | 2017-10-25 | 2018-01-23 | 北京富力通达科技有限公司 | Big load multi dimension load transducer and its demarcation metering method |
| KR101835728B1 (en) * | 2016-08-26 | 2018-03-07 | 주식회사 로보터스 | Calibration apparatus for 6-axis sensor |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH699670B1 (en) * | 2008-10-14 | 2012-04-30 | Kistler Holding Ag | Calibration device for measuring wheels. |
| CN105181241B (en) * | 2015-08-12 | 2018-02-09 | 中国石油大学(华东) | A kind of desk-top force loading device of adjustable working and its scaling method |
| CN109580089B (en) * | 2019-01-10 | 2020-04-21 | 东南大学 | Six-dimensional force sensor calibration device and calibration method thereof |
-
2019
- 2019-04-08 CN CN201910274531.2A patent/CN109870269B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5020357A (en) * | 1989-08-18 | 1991-06-04 | N. K. Biotechnical Engineering Company | Calibration stand for sensor |
| CN102135461A (en) * | 2010-12-14 | 2011-07-27 | 西北工业大学 | Undercarriage load calibration device and method for calibrating load of undercarriage by using device |
| CN102692319A (en) * | 2012-06-12 | 2012-09-26 | 西南交通大学 | Passive follow-up force-applied linear guiderail pair test bed with controllable load |
| CN103196629A (en) * | 2013-03-30 | 2013-07-10 | 大连交通大学 | Six-dimensional sensor calibration device |
| CN103604561A (en) * | 2013-11-27 | 2014-02-26 | 东南大学 | Calibration device and method of six-axis force/torque sensor |
| KR101835728B1 (en) * | 2016-08-26 | 2018-03-07 | 주식회사 로보터스 | Calibration apparatus for 6-axis sensor |
| CN107621422A (en) * | 2017-10-25 | 2018-01-23 | 北京富力通达科技有限公司 | Big load multi dimension load transducer and its demarcation metering method |
Non-Patent Citations (1)
| Title |
|---|
| 6-UPUR并联式六维测力平台静态性能标定研究;丁长涛;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20100815;C030-4 * |
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