CN104019750B - Device and method for measuring effective arm length of swing arm type contourgraph - Google Patents

Abstract

The invention relates to a device and a method for measuring the effective arm length of a swing arm type contourgraph, wherein the device consists of a first target ball, a second target ball, a fine adjustment mechanism, a cross arm support, a balancing weight, a computer, a first angle block, a cross arm rotary table, a second angle block, a laser tracker, a workpiece rotary table, a mirror surface to be measured, a contact type sensor and a working table surface; the cross arm rotates around the axial lead of the cross arm rotary table, circular arc tracks rotating around the axial lead of the cross arm rotary table are formed in space by the measuring head spherical center of the contact type sensor, the spherical center of the first target ball and the spherical center of the second target ball, the circular arc tracks formed in space by the spherical center of the first target ball and the spherical center of the second target ball are respectively tracked and measured by the laser tracker, and the distance from the measuring head spherical center of the contact type sensor to the axial lead of the cross arm rotary table, namely the effective arm length of the swing arm type contourgraph, is obtained through data processing of the computer.

Description

The measurement apparatus of a kind of swing-arm profilometry effective rake and method

Technical field

The invention belongs to geometric sense precision measurement field, relate to measurement apparatus and the method for swing-arm profilometry effective rake, it is adaptable to the measurement of swing-arm profilometry effective rake。

Background technology

The effective rake of swing-arm profilometry refers to: the gauge head centre of sphere of touch sensor is to the vertical dimension of transverse arm turntable axial line。

Swing-arm profilometry is the detecting instrument in place of a kind of effective optical fabrication process, its maximum feature is to be directly installed on by optical mirror plane to be measured, the turntable of optical fabrication lathe to be measured is used as the Work turning table of swing-arm profilometry, minute surface to be measured is realized detection in place。In swing-arm profilometry measurement process, the face shape result that swing-arm profilometry is measured by effective rake can produce impact；In the shape of effective rake opposite, point coordinates impacts, and exists under the premise of error at point coordinates, it is impossible to ensure that the continuation of minute surface is accurately processed；When utilizing swing-arm profilometry double testing head scanning data splicing to realize workpiece rotary table error separation, the measurement error of effective rake will affect the precision of data splicing。

Owing to the effective rake of swing-arm profilometry is a virtual geometric size in space, it is impossible to traditional geometric measurement method measurement, have no the relevant report that swing-arm profilometry effective rake is measured both at home and abroad。

Summary of the invention

(1) to solve the technical problem that

Impacting to solve point coordinates in the shape of prior art effective rake opposite, the measurement error of effective rake affects the technical problem of the precision of data splicing, it is an object of the invention to provide the measurement apparatus of the effective arm that can accurately measure swing-arm profilometry and method。

(2) technical scheme

A first aspect of the present invention, the measurement apparatus of a kind of swing-arm profilometry effective rake is provided, this device is made up of the first target ball, the second target ball, micro-adjusting mechanism, transverse arm, transverse arm bearing, balancing weight, computer, the first angle block gauge, transverse arm turntable, the second angle block gauge, laser tracker, workpiece rotary table, minute surface to be measured, touch sensor and work top, wherein: the first target ball, the second target ball are connected on micro-adjusting mechanism by magnetic-adsorption；One end of transverse arm is placed in the installing hole of micro-adjusting mechanism；One end of transverse arm bearing has a through hole, and the other end of transverse arm is placed in and passes through hole；Balancing weight is connected with the other end of transverse arm, for equilibrium contact formula sensor and transverse arm, in order to ensure the rotation of transverse arm turntable held stationary；The upper surface of the first angle block gauge is fixing with the bottom face of transverse arm bearing to be connected；Transverse arm turntable upper surface is fixing with the angled end-face of the first angle block gauge to be connected；The angled end-face of the second angle block gauge is fixing with transverse arm turntable lower surface to be connected；The lower surface of the second angle block gauge is fixedly mounted on work top；Laser tracker is disposed adjacent to the position of the axial line of transverse arm turntable, and ensures that laser tracker can not interfere transverse arm turntable to rotate, and the bottom face of laser tracker is placed on work top；Minute surface to be measured is positioned on workpiece rotary table；One end of touch sensor is connected with micro-adjusting mechanism, and the gauge head outline of touch sensor contacts with minute surface to be measured；Transverse arm rotates around the axial line of transverse arm turntable, touch sensor, the first target ball and the second target ball is driven to rotate around the axial line of transverse arm turntable, simultaneously the centre of sphere of the first target ball and the centre of sphere of the second target ball form the arc track that the axial line around transverse arm turntable rotates, the arc track that the centre of sphere of the centre of sphere and the second target ball that laser tracker distinguishes tracking measurement the first target ball is formed in space in space；Computer is connected with the data terminal of laser tracker by data acquisition line concentration, the arc track data process to the centre of sphere of the first target ball and the centre of sphere of the second target ball, it is thus achieved that swing-arm profilometry effective rake。

A second aspect of the present invention, it is provided that the measuring method of a kind of swing-arm profilometry effective rake, comprises the following steps that

Step S1: carried out coordinate translation conversion by the spatial relation of the gauge head centre of sphere of known touch sensor, the centre of sphere of the first target ball and the centre of sphere of the second target ball, obtain the first coordinate system, thus obtaining the centre of sphere of the gauge head centre of sphere of touch sensor, the centre of sphere of the first target ball and the second target ball coordinate under the first coordinate system；

Step S2: laser tracker measures the centre of sphere of the first target ball and the initial position of the centre of sphere of the second target ball, and the first target ball and the second target ball rotate the data on the arc track formed around transverse arm turntable；

Step S3: the first coordinate system is rotated translation and transforms to laser tracker coordinate system, obtains the gauge head centre of sphere of the touch sensor coordinate under laser tracker coordinate system；

Step S4: realize the process to data above by computer, obtain the gauge head centre of sphere distance to transverse arm turntable axial line of touch sensor, i.e. swing-arm profilometry effective rake。

(3) beneficial effect

The present invention compared with prior art has the advantage that the present invention adopts the method that laser tracker measures swing-arm profilometry effective rake, utilize the high-precision measuring characteristic of laser tracker, accurately measure effective rake, improve the certainty of measurement of effective rake, there is under the premise of error point coordinates in the shape of opposite impact thus eliminating effective rake, it is possible to ensure that the continuation of minute surface is accurately processed；Ensure that and utilize swing-arm profilometry double testing head scanning data splicing to realize the precision that workpiece rotary table error separates。This kind of method can measure effective rake more conveniently simultaneously, provides practical solution for swing-arm profilometry at the on-position measure that optical manufacturing is on-the-spot。

Accompanying drawing explanation

Fig. 1 is the structural representation that the present invention measures the device of swing-arm profilometry effective rake。

Fig. 2 is the method flow diagram that the present invention measures swing-arm profilometry effective rake。

Fig. 3 is the spatial relation of the gauge head centre of sphere of the centre of sphere of the first target ball, the centre of sphere of the second target ball and touch sensor。

Fig. 4 is the first coordinate system oxyz new after coordinate translation。

Fig. 5 is the centre of sphere of the centre of sphere of laser tracker scanning survey the first target ball and the second target ball。

Fig. 6 is disc and the center of circle solves with reference to figure。

Detailed description of the invention

For making the object, technical solutions and advantages of the present invention clearly understand, below in conjunction with specific embodiment, and with reference to accompanying drawing, the present invention is described in more detail。

As shown in Figure 1, the structure of the device that laser tracker measures swing-arm profilometry effective rake includes: first target ball the 1, second target ball 2, micro-adjusting mechanism 3, transverse arm 4, transverse arm bearing 5, balancing weight 6, computer the 7, first angle block gauge 8, transverse arm turntable the 9, second angle block gauge 10, laser tracker 11, workpiece rotary table 12, minute surface to be measured 13, touch sensor 14 and work top 15, wherein: first target ball the 1, second target ball 2 is connected on micro-adjusting mechanism 3 by magnetic-adsorption；One end of transverse arm 4 is placed in the installing hole of micro-adjusting mechanism 3；One end of transverse arm bearing 5 has a through hole, and the other end of transverse arm 4 is placed in and passes through hole；Balancing weight 6 is connected with the other end of transverse arm 4, for equilibrium contact formula sensor 14 and transverse arm 4, in order to ensure the rotation of transverse arm turntable 9 held stationary；The upper surface of the first angle block gauge 8 is fixing with the bottom face of transverse arm bearing 5 to be connected；Transverse arm turntable 9 upper surface is fixing with the angled end-face of the first angle block gauge 8 to be connected；The angled end-face of the second angle block gauge 10 is fixing with transverse arm turntable 9 lower surface to be connected；The lower surface of the second angle block gauge 10 is fixedly mounted on work top 15；Laser tracker 11 is disposed adjacent to the position of the axial line of transverse arm turntable 9, and ensures that laser tracker 11 can not interfere transverse arm turntable 9 to rotate, and the bottom face of laser tracker 11 is placed on work top 15；Minute surface 13 to be measured is positioned on workpiece rotary table 12；Workpiece rotary table 12 is installed on work top 15；One end of touch sensor 14 is connected with micro-adjusting mechanism 3, the gauge head outline of touch sensor 14 contacts with minute surface 13 to be measured, transverse arm 4 rotates around the axial line of transverse arm turntable 9, touch sensor the 14, first target ball 1 and the second target ball 2 is driven to rotate around the axial line of transverse arm turntable 9, simultaneously the centre of sphere of the first target ball 1 and the centre of sphere of the second target ball 2 form the arc track that the axial line around transverse arm turntable 9 rotates, the arc track that the centre of sphere of the centre of sphere and the second target ball 2 that laser tracker 11 distinguishes tracking measurement the first target ball 1 is formed in space in space；Computer 7 is connected with the data terminal of laser tracker 11 by data acquisition line concentration, obtains and arc track data process to the centre of sphere of the first target ball 1 and the centre of sphere of the second target ball 2, it is thus achieved that swing-arm profilometry effective rake。

First target ball the 1, second target ball 2 is made up of iron material, and be reflective, diameter is 0.5 inch, key reflections is from the laser of laser tracker 10, thus ensureing that laser tracker 10 can the centre of sphere of the centre of sphere of tracking measurement the first target ball 1 and the second target ball 2 data on the arc track that space is formed。

The finding range of laser tracker 11 is more than 60m, 5 μm/m of static measurement precision, and 10 μm/m of dynamic measurement precision, coordinate repeatability is better than 2.5 μm/m。

Workpiece rotary table 12 is the lathe turntable of processing site, is used for supporting minute surface 13 to be measured。

Touch sensor 14 resolving power is 25nm, and certainty of measurement is 50nm。

Micro-adjusting mechanism 3 can realize the fine setting in X-direction, Y direction, Z-direction, pitch orientation and beat direction。

Transverse arm 4 and transverse arm bearing 5, for connecting cross arm turntable 9 and touch sensor 14, and complete the rotary motion to touch sensor 14。

First angle block gauge the 8, second angle block gauge 10, is used for supporting transverse arm turntable 9 and transverse arm bearing 5, and makes transverse arm turntable 9 be maintained at the inclination angle of setting；The angular range of the first angle block gauge 8 is 20 °～40 °, the angular range of the second angle block gauge 10 is 20 °～40 °。

Transverse arm turntable 9 is high accuracy air-float turntable, and the end face run-out of transverse arm turntable 9 is 25nm, and it is 0.02 that the angle of transverse arm turntable 9 is rocked ", for realizing the rotary motion of touch sensor 14。

When the measurement apparatus of swing-arm profilometry effective rake of the present invention works, transverse arm 4 rotates around the axial line of transverse arm turntable 9, drive touch sensor 14, first target ball 1 and the second target ball 2 rotate around the axial line of transverse arm turntable 9, simultaneously the centre of sphere of the first target ball 1 and the centre of sphere of the second target ball 2 form the arc track that the axial line around transverse arm turntable 9 rotates in space, the arc track that laser tracker 11 centre of sphere of tracking measurement the first target ball 1 respectively and the centre of sphere of the second target ball 2 are formed in space, processed by the data of computer, it is the central coordinate of circle obtaining two sections of arc track place discs that the arc track data of the centre of sphere of the first target ball 1 and the centre of sphere of the second target ball 2 are processed, utilize the central coordinate of circle of two sections of arc track place discs, namely the space line equation obtaining two central coordinate of circle is the axial line equation of transverse arm turntable；Recycling spatial point and the range equation of space line, obtain the gauge head centre of sphere that obtains touch sensor 14 to the distance of transverse arm turntable 9 axial line, i.e. swing-arm profilometry effective rake。

Being illustrated in figure 2 the measuring method of swing-arm profilometry effective rake, described measuring method utilizes the measuring process of the measurement apparatus of swing-arm profilometry effective rake to include:

Step S1: carried out coordinate translation conversion by the spatial relation of the gauge head centre of sphere of known touch sensor 14, the centre of sphere of the first target ball 1 and the centre of sphere of the second target ball 2, obtain the first coordinate system, thus obtaining the centre of sphere of the gauge head centre of sphere of touch sensor 14, the centre of sphere of the first target ball 1 and the second target ball 2 coordinate under the first coordinate system；

It is illustrated in figure 3 gauge head centre of sphere spatial relation under a certain coordinate system of the centre of sphere of the first target ball 1, the centre of sphere of the second target ball 2 and touch sensor 14: the sphere centre coordinate of the first target ball 1 is (X₁Y₁Z₁), the sphere centre coordinate of the second target ball 2 is (X₂Y₂Z₂), the gauge head sphere centre coordinate of touch sensor 14 is (X₃Y₃Z₃)。By coordinate translation formula, the zero of a certain coordinate system moving to the centre of sphere place of the second target ball 2, the new rectangular coordinate system that note now obtains is the first coordinate system oxyz, as shown in Figure 4。The translation matrix being tied to the first coordinate system by a certain coordinate is [Δ x₁Δy₁Δz₁]^T, then have:

$\left[\begin{array}{c}{X}_2\\ Y_2\\ Z_2\end{array}\right]+\left[\begin{array}{c}{\mathrm{\Δx}}_1\\ {\mathrm{\Λy}}_1\\ {\mathrm{\Δz}}_1\end{array}\right]=\left[\begin{array}{c}0\\ 0\\ 0\end{array}\right]---\left(1\right)$

Δ x in formula₁、Δy₁、Δz₁For translation matrix parameter, then have: [Δ x₁Δy₁Δz₁]^T=[-X₂-Y₂-Z₂]^T, it is hereby achieved that the coordinate respectively (X that the gauge head centre of sphere of the centre of sphere of the first target ball 1 and touch sensor 14 is under the first coordinate system₁-X₂Y₁-Y₂Z₁-Z₂), (X₃-X₂Y₃-Y₂Z₃-Z₂)。

The to sum up gauge head centre of sphere of the centre of sphere of the first target ball 1, the centre of sphere of the second target ball 2 and touch sensor 14 coordinate respectively (X under the first coordinate system₁-X₂Y₁-Y₂Z₁-Z₂), (000), (X₃-X₂Y₃-Y₂Z₃-Z₂)。

Step S2: laser tracker 11 measures the centre of sphere of the first target ball 1 and the initial position of the centre of sphere of the second target ball 2, and the first target ball 1 and the second target ball 2 rotate the data on the arc track formed around transverse arm turntable 9。

First target ball the 1, second target ball 2 and touch sensor 14 are positioned over initial position shown in Fig. 1, laser tracker 11 measures centre of sphere initial position space coordinates under laser tracker 11 coordinate system of the centre of sphere of the first target ball 1, the second target ball 2 respectively, the centre of sphere of the first target ball 1, the second target ball 2 the coordinate respectively (X of the centre of sphere₁₀Y₁₀Z₁₀)、(X₂₀Y₂₀Z₂₀)。Then the track that rotates around transverse arm turntable 9 axial line of the centre of sphere of the centre of sphere of laser tracker 11 spotting scaming the first target ball 1, the second target ball 2, it is (X that laser tracker 11 records the data of the centre of sphere of the first target ball 1 coordinate on rotational trajectory₁₁Y₁₁Z₁₁)、(X₁₂Y₁₂Z₁₂)、…、(X_1iY_1iZ_1i)、…、(X_1nY_1nZ_1n), it is (X that laser tracker 11 records the data of the centre of sphere of the second target ball 2 coordinate on rotational trajectory₂₁Y₂₁Z₂₁)、(X₂₂Y₂₂Z₂₂)、…、(X_2iY_2iZ_2i)、…、(X_2nY_2nZ_2n), as shown in Figure 5。

Step S3: the first coordinate system is rotated translation and transforms to laser tracker coordinate system, it is possible to obtain the gauge head centre of sphere of touch sensor 14 coordinate under laser tracker coordinate system。

By the gauge head centre of sphere of the centre of sphere of the first target ball 1, the centre of sphere of the second target ball 2 and touch sensor 14 coordinate (X under the first coordinate system₁-X₂Y₁-Y₂Z₁-Z₂)、(000)、(X₃-X₂Y₃-Y₂Z₃-Z₂) be transformed under laser tracker 11 coordinate system, it is necessary to by the rotation translation transformation of coordinate system。Might as well remembering that spin matrix is R, translation matrix is PL。

All lay respectively at due to the centre of sphere of the centre of sphere of the first target ball 1, the second target ball 2 under first coordinate system and laser tracker 11 coordinate system, then have:

$\left\{\begin{array}{c}\begin{array}{c}\left[\begin{array}{c}{X}_{10}\\ Y_{10}\\ Z_{10}\end{array}\right]=R\left[\begin{array}{c}{X}_1-X_2\\ Y_1-Y_2\\ Z_1-Z_2\end{array}\right]+\mathrm{PL}\end{array}\\ \left[\begin{array}{c}{X}_{20}\\ Y_{20}\\ Z_{20}\end{array}\right]=\mathrm{PL}\end{array}\right.---\left(2\right)$

In formula, R is spin matrix, and PL is translation matrix, it is possible to obtain:

PL=[X₂₀Y₂₀Z₂₀]^T(3)

$\left[\begin{array}{c}{X}_{10}-X_{20}\\ Y_{10}-Y_{20}\\ Z_{10}-Z_{20}\end{array}\right]/\left[\begin{array}{c}{X}_1-X_2\\ Y_1-Y_2\\ Z_1-Z_2\end{array}\right]---\left(4\right)$

In formula, "/" is that the right side of matrix is removed。

The gauge head centre of sphere of note touch sensor 14 position under laser tracker 11 coordinate system is P point, if the coordinate of P is (X₀Y₀Z₀), then have:

$\left[\begin{array}{c}{X}_0\\ Y_0\\ Z_0\end{array}\right]=R\left[\begin{array}{c}{X}_3-X_2\\ Y_3-Y_2\\ Z_3-Z_2\end{array}\right]+\mathrm{PL}---\left(5\right)$

Step S4: realize the process to data above by computer, obtain the gauge head centre of sphere distance to transverse arm turntable axial line of touch sensor, i.e. swing-arm profilometry effective rake。

Simulate transverse arm turntable 9 axial line equation in laser tracker 11 coordinate system, need the centre of sphere simulating the centre of sphere of the first target ball 1 and the second target ball 2 central coordinate of circle of the disc at place under laser tracker 11 coordinate system, be below the solution procedure of the central coordinate of circle of the centre of sphere arc track place plane of the first target ball 1 and be illustrated in conjunction with Fig. 6。

O is the center of circle of the centre of sphere arc track place disc of the first target ball 1, P₀、P₁、P₀₁For the point on track。First plane P is obtained₀P₁The equation of O, if AX_1i+BY_1i+CZ_1i-D=0。When measuring, plane is without initial point, therefore just can make D=1 herein。The centre of sphere arc track of the first target ball 1 all on this plane, then has:

$\left[\begin{array}{ccc}{X}_{10}& Y_{10}& Z_{10}\\ X_{11}& Y_{11}& Z_{11}\\ .& .& .\\ .& .& .\\ .& .& .\\ X_{1n}& Y_{1n}& Z_{1n}\end{array}\right]*\left[\begin{array}{c}A\\ B\\ C\end{array}\right]-\left[\begin{array}{c}1\\ 1\\ .\\ .\\ .\\ 1\end{array}\right]=0---\left(6\right)$

In formula, A, B, C are plane equation parameter, and note N is coefficient matrix, then $N=\left[\begin{array}{ccc}{X}_{10}& Y_{10}& Z_{10}\\ X_{11}& Y_{11}& Z_{11}\\ .& .& .\\ .& .& .\\ .& .& .\\ X_{1n}& Y_{1n}& Z_{1n}\end{array}\right],l=\left[\begin{array}{c}1\\ 1\\ .\\ .\\ .\\ 1\end{array}\right],$ Can obtain: $\left[\begin{array}{c}A\\ B\\ C\end{array}\right]={\left(N^{T}N\right)}^{-1}{N}^{T}l.$

In figure 6, if the coordinate of O is (x₀y₀z₀), vector $\stackrel{\→}{P_0{P}_1}=(X_{11}-X_{10},Y_{11}-Y_{10},Z_{11}-Z_{10}),$ P₀₁It is a P₀And P₁Midpoint, it is easy to obtain $\stackrel{\→}{{\mathrm{OP}}_{01}},$ Then have:

Δx₀₁x₀+Δy₀₁y₀+Δz₀₁z₀-l₀=0 (7)

Δ x in formula₀₁=X₁₁-X₁₀, Δ y₀₁=Y₁₁-Y₁₀, Δ z₀₁=Z₁₁-Z₁₀, $l_0=\frac{(X_{11}^2+Y_{11}^2+Z_{11}^2)-(X_{10}^2+Y_{10}^2+Z_{10}^2)}{2}.$

By the centre of sphere arc track data (X of the first target ball 1₁₀Y₁₀Z₁₀)、(X₁₁Y₁₁Z₁₁)、(X₁₂Y₁₂Z₁₂)、…、(X_1iY_1iZ_1i)、…、(X_1nY_1nZ_1n) this (n+1) individual point can list the middle vertical plane equation of n linear independence, itself and (6) formula simultaneous are obtained:

$\left[\begin{array}{ccc}A& B& C\\ {\mathrm{\Δx}}_{01}& {\mathrm{\Δy}}_{01}& {\mathrm{\Δz}}_{01}\\ {\mathrm{\Δx}}_{12}& {\mathrm{\Δy}}_{12}& {\mathrm{\Δz}}_{12}\\ .& .& .\\ .& .& .\\ .& .& .\\ {\mathrm{\Δx}}_{(n-1)n}& {\mathrm{\Δy}}_{(n-1)n}& \mathrm{\Δ}{z}_{(n-1)n}\end{array}\right]*\left[\begin{array}{c}{x}_0\\ y_0\\ z_0\end{array}\right]=\left[\begin{array}{c}1\\ l_0\\ l_1\\ .\\ .\\ .\\ l_{(n-1)}\end{array}\right]---\left(8\right)$

X in formula₀、y₀、z₀For O point coordinates parameter, note W is coefficient matrix, $W=\left[\begin{array}{ccc}A& B& C\\ {\mathrm{\Δx}}_{01}& {\mathrm{\Δy}}_{01}& {\mathrm{\Δz}}_{01}\\ {\mathrm{\Δx}}_{12}& {\mathrm{\Δy}}_{12}& {\mathrm{\Δz}}_{12}\\ .& .& .\\ .& .& .\\ .& .& .\\ {\mathrm{\Δx}}_{(n-1)n}& {\mathrm{\Δy}}_{(n-1)n}& \mathrm{\Δ}{z}_{(n-1)n}\end{array}\right],L_1=\left[\begin{array}{c}1\\ l_0\\ l_1\\ .\\ .\\ .\\ l_{(n-1)}\end{array}\right],$ Can obtain $\left[\begin{array}{c}{x}_0\\ y_0\\ z_0\end{array}\right]={\left(W^{T}W\right)}^{-1}{W}^T{L}_1.$

The central coordinate of circle processing procedure of the centre of sphere arc track place disc of the second target ball 2 is the same with the central coordinate of circle processing procedure of the centre of sphere arc track place disc of the first target ball 2, no longer it is discussed in detail herein, if trying to achieve the center of circle O of the centre of sphere arc track place disc of the second target ball 2₁Coordinate is (x₁y₁z₁), now transverse arm turntable 9 axial line place space line is OO₁, as shown in Figure 5。

Now effective rake L refers to the gauge head centre of sphere P to transverse arm turntable 9 axial line place space line OO of touch sensor 14₁Vertical dimension,Straight line OO₁Equation be:

$\frac{x-x_1}{x_1-x_0}=\frac{y-y_1}{y_1-y_0}=\frac{z-z_1}{z_1-z_0}---\left(9\right)$

Range equation by spatial point to space line, it is possible to obtain P (X₀Y₀Z₀) to straight line OO₁Vertical dimension:

$L=\left|\frac{\left|\begin{array}{ccc}i& j& k\\ x_1-x_0& y_1-y_0& z_1-z_0\\ X_0-x_1& Y_0-y_1& Z_0-z_1\end{array}\right|}{\sqrt{{(x_1-x_0)}^2+{(y_1-y_0)}^2+{(z_1-z_0)}^2}}\right|---\left(10\right)$

In formula, i, j, k is rectangular coordinate system unit vector。

The above; being only the detailed description of the invention in the present invention, but protection scope of the present invention is not limited thereto, any people being familiar with this technology is in the technical scope that disclosed herein; it is appreciated that the conversion or replacement expected, all should be encompassed in comprising within scope of the present invention。

Claims (8)

1. the measurement apparatus of a swing-arm profilometry effective rake, it is characterized in that: be made up of the first target ball, the second target ball, micro-adjusting mechanism, transverse arm, transverse arm bearing, balancing weight, computer, the first angle block gauge, transverse arm turntable, the second angle block gauge, laser tracker, workpiece rotary table, minute surface to be measured, touch sensor and work top, wherein: the first target ball, the second target ball are connected on micro-adjusting mechanism by magnetic-adsorption；One end of transverse arm is placed in the installing hole of micro-adjusting mechanism；One end of transverse arm bearing has a through hole, and the other end of transverse arm is placed in and passes through hole；Balancing weight is connected with the other end of transverse arm, for equilibrium contact formula sensor and transverse arm, in order to ensure the rotation of transverse arm turntable held stationary；The upper surface of the first angle block gauge is fixing with the bottom face of transverse arm bearing to be connected；Transverse arm turntable upper surface is fixing with the angled end-face of the first angle block gauge to be connected；The angled end-face of the second angle block gauge is fixing with transverse arm turntable lower surface to be connected；The lower surface of the second angle block gauge is fixedly mounted on work top；Laser tracker is disposed adjacent to the position of the axial line of transverse arm turntable, and ensures that laser tracker can not interfere transverse arm turntable to rotate, and the bottom face of laser tracker is placed on work top；Minute surface to be measured is positioned on workpiece rotary table；One end of touch sensor is connected with micro-adjusting mechanism, and the gauge head outline of touch sensor contacts with minute surface to be measured；Transverse arm rotates around the axial line of transverse arm turntable, touch sensor, the first target ball and the second target ball is driven to rotate around the axial line of transverse arm turntable, simultaneously the centre of sphere of the first target ball and the centre of sphere of the second target ball form the arc track that the axial line around transverse arm turntable rotates, the arc track that the centre of sphere of the centre of sphere and the second target ball that laser tracker distinguishes tracking measurement the first target ball is formed in space in space；Computer is connected with the data terminal of laser tracker by data acquisition line concentration, the arc track data process to the centre of sphere of the first target ball and the centre of sphere of the second target ball, it is thus achieved that swing-arm profilometry effective rake。

2. the measurement apparatus of swing-arm profilometry effective rake according to claim 1, it is characterised in that: the finding range of described laser tracker is more than 60m, 5 μm/m of static measurement precision, and 10 μm/m of dynamic measurement precision, coordinate repeatability is better than 2.5 μm/m。

3. the measurement apparatus of swing-arm profilometry effective rake according to claim 1, it is characterized in that: the arc track data of the centre of sphere of the described centre of sphere to the first target ball and the second target ball process, it it is the central coordinate of circle obtaining two sections of arc track place discs, utilize the central coordinate of circle of two sections of arc track place discs, it is thus achieved that namely the space line equation of two central coordinate of circle is the axial line equation of transverse arm turntable；The range equation of recycling spatial point and space line, obtains the gauge head centre of sphere distance to transverse arm turntable axial line of touch sensor, is the effective rake of swing-arm profilometry。

4. the measurement apparatus of swing-arm profilometry effective rake according to claim 1, it is characterized in that: described first target ball, the second target ball are made up of iron material, and be reflective, for reflecting the laser from laser tracker, thus ensureing the centre of sphere of the centre of sphere of laser tracker tracking measurement the first target ball and the second target ball data on the arc track that space is formed。

5. the measurement apparatus of swing-arm profilometry effective rake according to claim 1, it is characterised in that: the resolving power of described touch sensor is 25nm, and certainty of measurement is 50nm。

6. the measurement apparatus of swing-arm profilometry effective rake according to claim 1, it is characterised in that: described micro-adjusting mechanism is the fine setting that can realize X-direction, Y direction, Z-direction, pitch orientation and beat direction。

7. the measurement apparatus of swing-arm profilometry effective rake according to claim 1, it is characterized in that: described transverse arm turntable is air-float turntable, the end face run-out of transverse arm turntable is 25nm, and it is 0.02 that the angle of transverse arm turntable is rocked ", for realizing the rotary motion of touch sensor。

8. the method that swing-arm profilometry effective rake is measured by the measurement apparatus according to any one of claim 1～7, comprises the following steps that

Step S1: carried out coordinate translation conversion by the spatial relation of the gauge head centre of sphere of known touch sensor, the centre of sphere of the first target ball and the centre of sphere of the second target ball, obtain the first coordinate system, thus obtaining the centre of sphere of the gauge head centre of sphere of touch sensor, the centre of sphere of the first target ball and the second target ball coordinate under the first coordinate system；

Step S2: laser tracker measures the centre of sphere of the first target ball and the initial position of the centre of sphere of the second target ball, and the first target ball and the second target ball rotate the data on the arc track formed around transverse arm turntable；

Step S3: the first coordinate system is rotated translation and transforms to laser tracker coordinate system, obtains the gauge head centre of sphere of the touch sensor coordinate under laser tracker coordinate system；

Step S4: realize the process to data above by computer, obtain the gauge head centre of sphere distance to transverse arm turntable axial line of touch sensor, i.e. swing-arm profilometry effective rake。