CN107607070A - A kind of articulated arm coordinate measuring machine thermal deformation errors recognize bearing calibration - Google Patents
A kind of articulated arm coordinate measuring machine thermal deformation errors recognize bearing calibration Download PDFInfo
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- CN107607070A CN107607070A CN201710897408.7A CN201710897408A CN107607070A CN 107607070 A CN107607070 A CN 107607070A CN 201710897408 A CN201710897408 A CN 201710897408A CN 107607070 A CN107607070 A CN 107607070A
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Abstract
The invention discloses a kind of articulated arm coordinate measuring machine thermal deformation errors to recognize bearing calibration, sets hot monitoring point at the pedestal of joint arm, measuring arm, joint and gauge head respectively, records temperature rise-time changing curve of each monitoring point；Operation coordinate measuring machine is measured to standard gauge block, and each hot monitoring point measurement error, experimental error compensation model is established according to arithmetic of linearity regression equivalent to the temperature rise value of laboratory temperature to the temperature rise value and thermal deformation errors value of seven hot monitoring points of joint arm.Undetermined parameter is determined using least square method, the measurement result of articulated arm coordinate measuring machine is compensated.The present invention can draw the mapping relations that temperature rise changes between articulated arm coordinate measuring machine length-measuring error and corresponding each temperature monitoring point；The body thermal deformation error compensation model based on multilinear fitting is established based on the mapping relations, thermal deformation error compensation is realized, improves the measurement accuracy of joint arm.
Description
Technical field
The present invention relates to articulated arm coordinate measuring machine field, and in particular to a kind of articulated arm coordinate measuring machine thermal deformation
Error identification bearing calibration.
Background technology
Articulated arm coordinate measuring machine (hereinafter referred joint arm) is the high precision instrument for realizing measurement of coordinates, is surveyed in coordinate
During amount, because the change of joint arm internal circuit and environment temperature can cause the thermal deformation of body, so as to introduce measuring force
Error, body thermal deformation be influence joint arm measurement accuracy an important factor for, due to the presence of thermal deformation so that joint arm it is true
Real structural parameters, which move, learns equation mismatch, so as to bring larger measurement error.Although can be by being carried out to joint arm
Regularly calibrate to reduce gauge head error, but calibrate and measurement process in generally have ignored internal body and generate heat this factor
Influence to improve the measurement accuracy of joint arm, therefore, grasp joint arm because inner heat produces the mechanism of Thermal Error, contribute to
Further improve its measurement accuracy.
The content of the invention
The purpose of the present invention is a kind of articulated arm coordinate measuring machine thermal deformation errors identification bearing calibration of design.
For achieving the above object, the technical scheme is that：A kind of articulated arm coordinate measuring machine thermal deformation misses
Difference identification bearing calibration, comprises the following steps：
Step 1) control laboratory temperature to be monitored in real time at 20 DEG C or so, and to laboratory temperature；
Step 2) m hot monitoring points are set at the pedestal of joint arm, measuring arm, joint and gauge head respectively, to above-mentioned m
Individual hot monitoring point is equipped with real time temperature logging modle, record joint arm from start reach thermal balance when each monitoring point temperature become
Change, and draw temperature rise-time changing curve of each monitoring point；
Step 3) operation coordinate measuring machine carries out random measurement in chronological order to standard gauge block, and it is random using surveying every time
Amount is multiple, averages as measured distance, i.e. measured value, and the difference of the standard value of measured value and standard gauge block is joint arm
Measurement error；
Step 4) every the set time, to step 2) in hot monitoring point temperature measuring and recording, and to step 3) Plays
Distance carries out one-shot measurement；Draw n group test datas, including each hot monitoring point equivalent to the temperature rise value Δ T of laboratory temperatureij(i
=1,2 ..., m；J=1,2 ..., n), measurement error Δ E of the joint arm to gauged distancej(j=1,2 ..., n)；
Step 5) temperature rise value and thermal deformation errors value according to arithmetic of linearity regression to seven hot monitoring points of joint arm
Experimental error compensation model is established, the form of institute's established model is：
E=A0+A1ΔT1j+A2ΔT2j+…+AmΔTmj
J=1,2 in formula ..., n；ΔT1j, Δ T2j..., Δ TmjRepresent 1,2 respectively ..., m hot monitoring points the j moment with
The temperature rise value of laboratory temperature；A0, A1..., AmRespectively undetermined parameter；
Step 6) according to step 4) in n group test datas, undetermined parameter A is determined using least square method0, A1..., Am,
Bring step 5 into) in test error compensation model, obtain articulated arm coordinate measuring machine thermal deformation error compensation model；
Step 7) use step 6) obtained error compensation formula, the measurement result of articulated arm coordinate measuring machine is entered
Row compensation.
The beneficial effects of the invention are as follows：
1) this method can draw warm between articulated arm coordinate measuring machine length-measuring error and corresponding each temperature monitoring point
Rise the mapping relations of change；
2) the body thermal deformation error compensation model based on multilinear fitting is established based on the mapping relations, realizes thermal change
Shape error compensation, improve the measurement accuracy of joint arm.
Brief description of the drawings
Fig. 1 is articulated arm coordinate measuring machine and hot monitoring point distribution map；
Fig. 2 is temperature-time changing curve of each hot monitoring point；
The prediction error curve diagram of Fig. 3 measurement errors and compensation model；
Fig. 4 uses step 6) compensation model compensation fore-and-aft survey precision curve map；
Table 1 is each hot monitoring point temperature rise value, measurement error data；
Table 2 is measurement Error Compensation fore-and-aft survey precision extreme value and average value.
Embodiment
The technical scheme in the embodiment of the present invention is clearly and completely described below in conjunction with accompanying drawing.
The present invention is directed to this factor of thermal deformation errors expansion detection method analysis caused by joint arm temperature, passes through design
One simple method for measuring, joint arm is subjected to measurement of coordinates in the case where considering thermal deformation, research finds machine thermal deformation
Influence to articulated arm coordinate measuring machine measurement accuracy is very big, and the error to caused by body thermal deformation compensates.The hair
The bright influence for fully taking into account the thermal deformation of articulated arm coordinate measuring machine body to measurement accuracy, sat for the follow-up articulated arm that improves
The measurement accuracy of co-ordinate measuring machine provides a kind of detection method.
As shown in figure 1, a kind of articulated arm coordinate measuring machine thermal deformation errors identification bearing calibration, articulated arm coordinate are surveyed
The critical piece of amount machine (hereinafter referred joint arm), including pedestal 1, measuring arm 2, measurement joint 3 and gauge head 4.
Step 1) control laboratory temperature to be monitored in real time at 20 DEG C or so, and to laboratory temperature；
Step 2) 7 hot monitoring points of the setting at the pedestal 1 of joint arm, measuring arm 2, joint 3 and gauge head 4 respectively, and
Respectively marked as P1, P2, P3, P4, P5, P6, P7, real time temperature logging modle is equipped with to above-mentioned 7 hot monitoring points, is recorded
Joint arm from start reach thermal balance when each monitoring point temperature change, by laboratory temperature synchronous recording, and be labeled as P8,
Counting statistics draws temperature-time changing curve of each hot monitoring point, as shown in Figure 2.
Step 3) standard gauge block of band cone nest is used in the present embodiment as etalon, the gauged distance between cone nest is
361.910mm.Operation coordinate measuring machine carries out random measurement in chronological order to the cone nest distance of standard gauge block, adopts at random every time
With measurement 5 times, average and as closed for measured distance, i.e. measured value, the difference of measured value and the gauged distance of cone nest distance
The measurement error of joint arm；
Step 4) every 5 minutes, to step 2) in hot monitoring point temperature measuring and recording, and to step 3) in cone nest away from
From progress one-shot measurement；Test duration 150 minutes, 30 groups of test datas are drawn, as shown in table 1, including each hot monitoring point is suitable
In the temperature rise value Δ T of laboratory temperatureij(i=1,2 ..., 7；J=1,2 ..., 30), measurement error of the joint arm to gauged distance
ΔEj(j=1,2 ..., 30).
Each hot monitoring point temperature rise value of table 1, measurement error data
Step 5) the thermal deformation error compensation model based on multiple linear regression.
The mathematical modeling of Thermal Error and the temperature rise of each position monitoring point is established using multiple linear regression analysis method.Multiple linear returns
The principle returned is：If dependent variable y and each independent variable x of other m1,x2,…,xmBetween inner link be linear, and according to reality
Test and draw observation data (x1,x2,…,xm；Y), then observed data can have following structure type：
Y=β0+β1x1+β2x2+,…,+βmxm
In formula, β0, β1..., βmIt is m+1 parameters to be estimated；x1,x2,…,xmOne that can measure or control for m
As variable.
The temperature rise value and thermal deformation errors value of seven hot monitoring points of joint arm are established according to arithmetic of linearity regression real
Error compensation model is tested, the form of institute's established model is：
E=A0+A1ΔT1j+A2ΔT2j+…+A7ΔT7j
In formula：J=1,2 ..., 30；E is thermal deformation errors；ΔT1j, Δ T2j..., Δ T7jRepresent respectively hot monitoring point P1,
The temperature rise value of P2, P3, P4, P5, P6, P7 at the j moment relative to laboratory temperature P8；A0, A1..., A7Respectively undetermined parameter.
Step 6) according to step 4) 30 groups of test datas in table 1, undetermined parameter A is determined using least square method0,
A1..., A7.Bring step 5 into) in test error compensation model, obtain the compensation formula of joint arm thermal deformation errors.
Parameter A0, A1..., A7Determination, with 7 degree of freedom high-tech Co., Ltd develop the analysis integrated instrument of mathematical optimization it is soft
Part 1stOPt, input the undetermined parameter to be recognized (Parameters) A0, A1..., A7, each sensor temperature rise changing value Δ T1,
ΔT2…,ΔT7And measurement error value (Variable) Δ Ej(j=1,2 ..., 30).And to determine being pattern function
(Function) E=A0+A1ΔT1j+A2ΔT2j+…+A7ΔT7j, and bring the experimental data of table 1 into.
Optimized algorithm is set, using simulated annealing, and carries out the setting (selection acquiescence) of algorithm parameter.Click on fortune
OK, A is drawn0,A1…,A7Identification result it is as follows：
A0=-0.118, A1=0.092, A2=0.010, A3=0.164, A4=0.213, A5=-0.207, A6=-
0.008、A7=-0.129
Therefore, the articulated arm coordinate measuring machine thermal deformation error compensation model based on multiple linear regression of foundation is：
E=-0.118+0.092 Δs T1+0.010ΔT2+0.164ΔT3+0.213ΔT4
-0.207ΔT5-0.008ΔT6-0.129ΔT7
Step 7) use step 6) obtained error compensation model, the measurement result of articulated arm coordinate measuring machine is entered
Row compensation.
To verify the validity of compensation model, the compensation model drawn to experiment is verified, is contrasted the experiment drawn and is surveyed
The evaluated error (error calculated using compensation model) for measuring error and compensation model is as shown in Figure 3.And according to error compensation
Model carries out error compensation to measurement data, i.e., the measurement error of articulated arm coordinate measuring machine is subtracted to the estimation of compensation model
Error, so as to the measurement accuracy after being compensated, effect is as shown in Fig. 4 and table 2 before and after contrast compensation.
| Before error compensation | After error compensation | Percentage (%) | |
| Maximum (mm) | 0.179 | 0.0936 | 47.7% |
| Minimum value (mm) | 0.002 | 0.00064 | 68% |
| Average value (mm) | 0.0715 | 0.0335 | 53.15% |
The measurement Error Compensation fore-and-aft survey precision extreme value of table 2 and average value
As can be seen that measurement error maximum, minimum value and average value after joint arm error compensation are equal from Fig. 4, table 2
Decrease, maximum error of measuring is reduced to 0.0936mm from 0.179mm, reduces 47.7%；Average measurement error from
0.0715mm is reduced to 0.0335mm, is effectively improved the measurement accuracy of joint arm.
Described embodiment is only part of the embodiment of the present invention, rather than whole embodiments.Based on the present invention
In embodiment, the every other implementation that those of ordinary skill in the art are obtained under the premise of creative work is not made
Example, belongs to the scope of protection of the invention.
Claims (1)
1. a kind of articulated arm coordinate measuring machine thermal deformation errors recognize bearing calibration, it is characterised in that comprise the following steps：
Step 1) control laboratory temperature to be monitored in real time at 20 DEG C or so, and to laboratory temperature；
Step 2) m hot monitoring points are set at the pedestal of joint arm, measuring arm, joint and gauge head respectively, to above-mentioned m heat
Monitoring point be equipped with real time temperature logging modle, record joint arm from start reach thermal balance when each monitoring point temperature change,
And draw temperature rise-time changing curve of each monitoring point；
Step 3) operation coordinate measuring machine carries out random measurement in chronological order to standard gauge block, and it is random more using measuring every time
It is secondary, average as measured distance, i.e. measured value, the difference of measured value and standard gauge block standard value is that the measurement of joint arm misses
Difference；
Step 4) every the set time, to step 2) in hot monitoring point temperature measuring and recording, and to step 3) Plays distance
Carry out one-shot measurement；Draw n group test datas, including each hot monitoring point equivalent to the temperature rise value Δ T of laboratory temperatureij(i=1,
2 ..., m；J=1,2 ..., n), measurement error Δ E of the joint arm to gauged distancej(j=1,2 ..., n)；
Step 5) temperature rise value and thermal deformation errors value of seven hot monitoring points of joint arm are established according to arithmetic of linearity regression
Experimental error compensation model, the form of institute's established model are：
E=A0+A1ΔT1j+A2ΔT2j+…+AmΔTmj
J=1,2 in formula ..., n；ΔT1j, Δ T2j..., Δ Tmj1,2 is represented respectively ..., m hot monitoring points are at j moment and experiment
The temperature rise value of room temperature；A0, A1..., AmRespectively undetermined parameter；
Step 6) according to step 4) in n group test datas, undetermined parameter A is determined using least square method0, A1..., Am, bring into
Step 5) in test error compensation model, obtain articulated arm coordinate measuring machine thermal deformation error compensation model；
Step 7) use step 6) obtained error compensation model, the measurement result of articulated arm coordinate measuring machine is mended
Repay.
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| CN109612420A (en) * | 2019-01-10 | 2019-04-12 | 安徽理工大学 | A kind of determination method applied to the joint arm measuring machine optimum measurement area for realizing workpiece on-line measurement |
| CN109855533A (en) * | 2019-01-07 | 2019-06-07 | 安徽理工大学 | A kind of articulated arm coordinate measuring machine that can be driven certainly |
| CN111380587A (en) * | 2020-03-05 | 2020-07-07 | 广州能源检测研究院 | Method for compensating result error of measuring vertical tank capacity by adopting Monte Carlo method |
| CN111972759A (en) * | 2020-05-09 | 2020-11-24 | 上海云杉服装科技有限公司 | Manual measurement method and system using mathematical model and human body characteristic point positioning |
| CN112197723A (en) * | 2020-09-29 | 2021-01-08 | 中国航发动力股份有限公司 | Checking standard component and checking method of coordinate measuring machine |
| CN112344895A (en) * | 2020-12-10 | 2021-02-09 | 南昌航空大学 | Multi-parameter model and calibration method of articulated arm coordinate measuring machine |
| CN114571453A (en) * | 2022-03-03 | 2022-06-03 | 遨博（北京）智能科技有限公司 | Control method and control device for cooperative robot |
| CN114800516A (en) * | 2022-05-13 | 2022-07-29 | 珞石（北京）科技有限公司 | Robot motion compensation method aiming at thermal error |
| US11550291B2 (en) * | 2019-12-20 | 2023-01-10 | Hexagon Technology Center Gmbh | Advanced thermal compensation of mechanical processes |
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| CN114800516A (en) * | 2022-05-13 | 2022-07-29 | 珞石（北京）科技有限公司 | Robot motion compensation method aiming at thermal error |
| CN114800516B (en) * | 2022-05-13 | 2024-03-08 | 珞石（北京）科技有限公司 | Robot motion compensation method for thermal error |
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Application publication date: 20180119 |