CN102416581A - Hybrid measurement positioning method of part to be assembled in flexible assembly of airplane components - Google Patents

Abstract

The invention discloses a hybrid measurement method for positioning a part to be assembled in the flexible assembly process of airplane components, belonging to the research contents of modern manufacturing technology in the field of advanced manufacturing technology. The method is a measurement positioning method for establishing a relative positional relationship between automatic hole making equipment and the part to be assembled in the flexible assembly process of the airplane components. The method adopts a laser measurement apparatus as a rough positioning means of the hole making equipment and adopts photographing measurement equipment as a means of accurately positioning the part to be assembled, and realizes accurate positioning of the part to be assembled by two steps. Through the method, the problem of incoordination between the automatic hole making equipment and a workpiece to be assembled resulting from excessive error accumulation of the assembly process in the flexible assembly process of the airplane components is solved to a certain degree, and an effective means of using automatic equipment in the flexible assembly of the airplane components is provided.

Description

The hybrid measurement localization method of part to be assembled in the aircraft components flexible assembly

Technical field

The present invention relates to the hybrid measurement localization method of part to be assembled in a kind of aircraft components flexible assembly, belong to the advanced manufacturing technology area now for the The Study of Manufacturing Technology content.

Background technology

Aircraft flexible assembly technology is the characteristic that takes into full account as the aeronautical product of assembling object; Through technology such as flexible assembly design, flexible assembly fixture design, flexible assembly process optimization, flexible assembly information management, laser positioning and control, automatic drillings; Realize airplane component accurately location and assembling fast; Reduce assembly tooling kind and quantity, light, mechanical, electrical, control and information technology comprehensive integration, advanced aircraft mounting technology with higher automaticity.

At present, in aircraft components flexible assembly process, adopt automatic drilling equipment as benchmark aircraft components to be carried out drilling usually with the frock position.But part to be assembled is not directly located by frock usually, and repeatedly the position error accumulation is more, needs once more to its measurement and positioning.Make the field in aviation; Although adopt Digital Measuring Technique and means such as laser tracker, photogrammetric instrumentation, laser radar, IGPS in a large number; In the frock manufacturing; Aspects such as assembly part location have obtained implementing widely and utilization, have realized the auxiliary assembling of measurement in the aircraft flexible assembly process.But the utilization of these measurement means; Most to certain production link; Adopt single digitized measurement means to measure, shorter mention needs frock, part are realized the process of second positioning, and aspect the utilization of measurement means; As yet not according to the advantage scope of application of various measurement means, the location of adopting the mode of mixed positioning to realize assembling process.

Summary of the invention

For solving the orientation problem of accessory to be installed in the aircraft flexible assembly process, a kind of localization method that is suitable for that mixes with photogrammetry system based on laser tracker has been proposed.This method is accurately decided three partial contents such as method and is formed by hybrid locating method whole strategy and implementing procedure, drilling equipment coarse localization method and part to be assembled.Under the support of this method, can realize in the flexible assembly process, to the accurate location of part to be assembled.

This method is mixed use laser tracker and photogrammetric instrumentation; Adopt laser tracker to carry out coarse localization; Photogrammetric instrumentation carries out pinpoint strategy, and the location of accessory to be installed in the aircraft components flexible assembly is divided into accurately location two steps of drilling equipment coarse localization and part to be assembled.In drilling equipment coarse localization; Utilize laser tracker to pass through measurement to the target ball position; The setting at part zero point in the completion equipment; Set up the relativeness between the aircraft components coordinate system and aircraft components physical location in machine part coordinate system, the digital-to-analogue, be automation drilling equipment frock position accurately.In the accurate position fixing process of part to be assembled; Utilize photogrammetric instrumentation through treating the measurement of assembly tooling datum hole position; Accomplish the calculating of part to be assembled and frock relative error; And the mode through zero offset, accomplish compensation of error, for automation drilling equipment provides part position to be assembled accurately.

The present invention gives full play to the advantage of various measurement devices, for the realization that realizes the aircraft components flexible assembly provides a kind of effective technical means for the part to be assembled location of aircraft components flexible assembly process provides a kind of accurate localization method.

Description of drawings

The flow process of part hybrid measurement to be assembled location in the flexible assembly of Fig. 1 aircraft components

Contact figure between each coordinate system of Fig. 2

The flow path switch figure of Fig. 3 workpiece coordinate system and lathe coordinate system

Fig. 4 position of tool tip and target ball center of circle graph of a relation

The specific embodiment

One, hybrid locating method whole strategy and implementing procedure

Laser measuring apparatus has precision high, and the advantage that measuring speed is fast has stronger advantage in measuring large product.So adopt laser tracker as the frock in the hybrid measurement location and the measurement means of automation drilling equipment.The photogrammetric instrumentation volume is little, and is simple to operate, and data is easy, and stronger advantage is arranged when measuring single part.So adopt the measurement means of photogrammetric instrumentation as part position to be assembled in the hybrid measurement location.

The hybrid measurement position fixing process of part to be assembled is divided into two steps in the aircraft components flexible assembly.At first, set up the relative position relation of automation drilling equipment and frock, realize the coarse localization of drilling equipment through laser tracker.Secondly, compensate the position error that frock is treated assembly parts, the accurate location of realizing accessory to be installed through photogrammetric instrumentation.

The coarse localization of drilling equipment is set up the workpieces coordinate system of automation drilling equipment through laser tracker, to confirm the relative position of assembly tooling and Digit Control Machine Tool, for locating for the second time frock position accurately is provided.Orientate accurate location the second time of part hybrid measurement to be assembled location as, realized by photogrammetry system, is used for further confirming the accurate relative position of part to be assembled and automation brill riveting equipment.The second positioning flow chart of flexible drilling process is as shown in Figure 1:

Two, the realization of the coarse localization of drilling equipment

The coarse localization of drilling equipment is accomplished the setting at zero point of workpiece in the drilling equipment; Set up the relativeness of aircraft components coordinate system and aircraft components physical location in Machinetool workpiece coordinate system, the digital-to-analogue, for the numerical control program of drilling equipment provides aircraft components position accurately.

(1) space coordinates of flexible assembly cell

In flexible assembly cell; Usually at first rely on off-line programing and analogue system digital model in CATIA to operate to aircraft components; Generation is used for the numerical control program of digital control processing, and the back drives lathe by numerical control program, to carrying out drilling by the fixing aircraft components of flexible frock.According to this flow process, the relation between the coordinate system is as shown in Figure 2.The space at each coordinate system place can be divided into coordinate system and real space position (measurement coordinate system) in coordinate system in the digital-to-analogue, the digital control system.

(1) coordinate system in the digital-to-analogue

Coordinate system comprises full machine coordinate system and workpiece coordinate system in the digital-to-analogue.

Full part coordinate system: when setting up the aircraft components digital model, need the benchmark of a zero point as model of creation.The coordinate system of setting up zero point thus is full machine coordinate system; In the design process of aircraft product; For guaranteeing the uniformity of data base, each parts in the aircraft, assembly, part are all set up under unified coordinate system; So be called full machine coordinate system, this origin of coordinates is far away usually apart from the parts physical location.

Workpiece coordinate system: when logarithmic mode carries out numerical control programming, by the selected program origin of coordinates of programming personnel.This coordinate system should be consistent with workpiece coordinate system in the digital control system.The selection of this coordinate system does not have absolute requirement, but usually, for improving the readability of numerical control program, and with the X of this coordinate system, Y, the Z axle is unified with Digit Control Machine Tool, and selects the nearer position of distance part to be assembled as coordinate zero point.

(2) coordinate system in the lathe

Coordinate system comprises lathe zero point and workpiece zero point in the lathe.

Lathe zero point: lathe M at zero point is meant the zero point of lathe coordinate system, i.e. X=0, and Y=0, Z=0, by manufacturer's definition, the user can not change.Lathe is the basic point of lathe zero point, is the datum mark of other coordinate system such as workpiece coordinate system, programming coordinate system and lathe reference point.

Workpiece zero point: workpiece W at zero point is called programming zero point again, is the initial point of workpieces coordinate system.Identical with the workpiece coordinate system in the digital-to-analogue, workpiece can freely be selected zero point, is convenient programming and the calculating of minimizing coordinate figure, works and is preferably disposed on the position of being convenient to programme zero point.

(3) real space position

The real space position can be divided into frock physical location and aircraft components physical location.

Frock physical location: i.e. measurement coordinate system; In the flexible frock installation process; Need to use laser tracker that frock is respectively located intersection point and position installation, in position fixing process, by the measurement coordinate system under the normal temperature of setting up through coordinate basis point by the status requirement in the digital-to-analogue.The coordinate of frock under this coordinate system is identical with digital-to-analogue.

Aircraft components physical location: because laser tracker does not directly position parts; So there is certain deviation in position and the position in digital-to-analogue of aircraft components in the frock measurement coordinate system; This deviation is the position error of frock, can cause certain influence to the degree of accuracy of flexible assembly drilling.

(2) workpiece coordinate system of automation drilling equipment is set up

The workpiece coordinate system method for building up of automation drilling equipment is with the unified process of workpiece coordinate system in workpiece coordinate system in the digital-to-analogue and the Digit Control Machine Tool.In general digital control processing process, the tool position of processing is all supporting with anchor clamps, and arranged clear and definite workpiece zero point, only need realize the compensation of cutter through tool setting.And in flexible automation drilling unit, frock and equipment size are bigger, and independent the manufacturing, need after erecting yard is installed, to use laser tracker the mutual alignment relation of measurement and positioning lathe and frock.

Its concrete implementation method is through laser tracker, to find the lathe position of zero point in aircraft axes, and in digital-to-analogue with in the lathe, set up unified workpiece zero point respectively, the process of the workpiece coordinate system that foundation is consistent.Specifically need conversion (Fig. 3) through following several steps.

Step 1: use laser tracker, measure the infrastructural frame of frock,, the physical location of frock and the physical location of digital-to-analogue are unified according to target ball position in the digital-to-analogue and the target ball position reading in the actual measurement.Because the tool locating precision is higher, so can think, this process has been accomplished the physical location of workpiece to be processed (horizontal tail) and the unification of digital-to-analogue position.

Step 2: machine tool motion is easy to the position measured to certain, uses laser tracker that the lathe position of tool tip is measured, the relation between its measuring position and point of a knife physical location is as shown in Figure 4.Utilize trigonometric function through simple computation, can get, between physical location and measuring position, the negative sense value added of Z axle under lathe coordinate system.

Step 3: in the CATIA system, setting up coordinate figure is each point of measured value, and measurement data is imported in the CATIA system.

Step 4: according to general numerical-control processing method, select correct position,, and each change in coordinate axis direction and machine spindle direction unified, in CATIA, set up workpiece coordinate system with this as workpiece zero point.

Step 5: the operation lathe, read lathe X when measuring, Y, the coordinate figure (X of Z ₁, Y ₁, Z ₁).

Step 6: utilize measurement function among the CATIA, measure the lathe position of tool tip point position (X in set workpiece coordinate that in the 3rd step, is set up ₂, Y ₂, Z ₂), thus, calculate the required framework that carries out and be deflected to:

$\left\{\begin{array}{c}{X}_G=X_2-X_1\\ Y_G=Y_2-Y_1\\ Z_G=Z_2-Z_1\end{array}\right.$

In the formula, X _G, Y _G, Z _GBe required deflection.

Step 7: in lathe, be provided with zero partially, programming phases is at first called this zero unification that can accomplish lathe coordinate system and workpiece coordinate system partially.

Three parts to be assembled are accurately decided method

Through laser tracking measurement equipment, accomplished the unification of the position relation between automation drilling equipment and the assembly tooling.But not necessarily have direct positioning relation between part to be assembled and the assembly tooling, repeatedly the position error accumulation of back, location is excessive, need utilize photogrammetric instrumentation to further locating.

At part to be assembled two ends, two positions of each preboring system accurately the hole as baseline positioning hole.In the drilling process, photogrammetry system is measured the physical location of baseline positioning hole on the part to be assembled and the deviation of theoretical position through real-time, thereby calculates the accurate position of part to be assembled, and offers Digit Control Machine Tool.Accomplish behind this position fixing process lathe and treat Assembly part and directly locate, under parts locally coordinate system to be assembled, process,, improved positioning accuracy so reduced the error accumulation link.The converting algorithm that workpiece coordinate system is converted into parts locally coordinate system to be assembled is following:

If the home position of made two datum holes is A [x ₁, y ₁, z ₁], B [x ₂, y ₂, z ₂].

The error of measuring in A point place is: Δ A=[Δ x ' ₁, Δ y ' ₁, 0].

The error of measuring in B point place is: Δ B=[Δ x " ₂, Δ y " ₂, 0].

With A be the coordinate system of the former heart in lathe coordinate system, the direction cosines of each reference axis (that is, X, Y, the unit vector of Z axle in lathe coordinate system) note is done:

$r=\left[\begin{array}{cccc}{X}_1:& r_{11},& r_{21},& r_{31}\\ Y_1:& r_{12},& r_{22},& r_{32}\\ Z_1:& r_{13},& r_{23},& r_{33}\end{array}\right]$

With B be the coordinate system of the former heart in lathe coordinate system, the direction cosines of each reference axis note is done:

$R=\left[\begin{array}{cccc}{X}_2:& R_{11},& R_{21},& R_{31}\\ Y_2:& R_{12},& R_{22},& R_{32}\\ Z_2:& R_{13},& R_{23},& R_{33}\end{array}\right]$

Note, A, 2 real coordinate positions under the machine coordinate system of B are:

$A^{*}=[x_1^{*},y_1^{*},z_1^{*}]$ $B^{*}=[x_2^{*},y_2^{*},z_2^{*}]$

Then can know according to the space coordinate conversion theorem:

$\left[\begin{array}{c}{x}_1^{*}\\ y_1^{*}\\ z_1^{*}\end{array}\right]=\left[\begin{array}{c}{x}_1\\ y_1\\ z_1\end{array}\right]+\left[\begin{array}{ccc}{r}_{11}& r_{21}& r_{31}\\ r_{12}& r_{22}& r_{32}\\ r_{13}& r_{23}& r_{33}\end{array}\right]\×\left[\begin{array}{c}\mathrm{\Δ}{x}_1^{\′}\\ \mathrm{\Δ}{y}_1^{\′}\\ 0\end{array}\right]$

$\left[\begin{array}{c}{x}_2^{*}\\ {\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">y</figure-callout>}}_2^{*}\\ {\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">z</figure-callout>}}_2^{*}\end{array}\right]=\left[\begin{array}{c}{x}_2\\ y_2\\ {\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">z</figure-callout>}}_2\end{array}\right]+\left[\begin{array}{ccc}{R}_{11}& R_{21}& R_{31}\\ R_{12}& R_{22}& R_{32}\\ R_{13}& R_{23}& R_{33}\end{array}\right]\&times;\left[\begin{array}{c}\mathrm{\&Delta;}{x}_2^{\&prime;}\\ \mathrm{\&Delta;}{y}_2^{\&prime;}\\ 0\end{array}\right]$

Can know that according to the spatial deviation theory modification method is following.

Method one: the side-play amount in the Calculation of Three Dimensional space.

Note, whole side-play amount is:

Δ＝[Δx，Δy，Δz]

The anglec of rotation is [α, a beta, gamma]

Then have according to spin matrix:

$\left[\begin{array}{c}{x}_1^{*}\\ y_1^{*}\\ z_1^{*}\end{array}\right]=\left[\begin{array}{c}\mathrm{\&Delta;}x\\ \mathrm{\&Delta;}y\\ \mathrm{\&Delta;Z}\end{array}\right]+\left[\begin{array}{ccc}1& \mathrm{\&gamma;}& -\mathrm{\&beta;}\\ -\mathrm{\&gamma;}& 1& \mathrm{\&alpha;}\\ \mathrm{\&beta;}& -\mathrm{\&alpha;}& 1\end{array}\right]\&times;\left[\begin{array}{c}{x}_1\\ y_1\\ z_1\end{array}\right]$

With

$\left[\begin{array}{c}{x}_2^{*}\\ {\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">y</figure-callout>}}_2^{*}\\ {\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">z</figure-callout>}}_2^{*}\end{array}\right]=\left[\begin{array}{c}\mathrm{\&Delta;}x\\ \mathrm{\&Delta;}y\\ \mathrm{\&Delta;Z}\end{array}\right]+\left[\begin{array}{ccc}1& \mathrm{\&gamma;}& -\mathrm{\&beta;}\\ -\mathrm{\&gamma;}& 1& \mathrm{\&alpha;}\\ \mathrm{\&beta;}& -\mathrm{\&alpha;}& 1\end{array}\right]\&times;\left[\begin{array}{c}{x}_2\\ y_2\\ {\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">z</figure-callout>}}_2\end{array}\right]$

Wherein because rotation error is less, so be similar to cos α=1, sina=a arranged.

Because measurement data limited (being three like the measurement point number can all calculate each data) and α, the deviation of β can be by the correction of latter end actuator.So, its note is done 0.Separate it, can get:

$\mathrm{\&gamma;}=1/2\&CenterDot;[\frac{(y_1^{*}-y_1)-({\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">y</figure-callout>}}_2^{*}-y_2)}{x_2-x_1}+\frac{(x_1^{*}-x_1)-({\mathrm{<figure-callout\; id="2"\; label="x"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">x</figure-callout>}}_2^{*}-x_2)}{y_1-x_2}]$

$\mathrm{\&Delta;x}=x_1^{*}-x_1-y_1\&times;\mathrm{\&gamma;}$

$\mathrm{\&Delta;y}=y_1^{*}-y_1+x_1\&times;r$

$\mathrm{\&Delta;z}=\frac{(z_1^{*}-z_1)+({\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">z</figure-callout>}}_2^{*}-z_2)}{2}$

Method two: only calculate the error on XOY plane.

Note, whole side-play amount is:

Δ＝[Δx，Δy]

The anglec of rotation is α

Then have according to spin matrix:

$\left[\begin{array}{c}{x}_1^{*}\\ y_1^{*}\end{array}\right]=\left[\begin{array}{c}\mathrm{\&Delta;x}\\ \mathrm{\&Delta;y}\end{array}\right]+\left[\begin{array}{cc}1& \mathrm{\&alpha;}\\ -\mathrm{\&alpha;}& 1\end{array}\right]\&times;\left[\begin{array}{c}{x}_1\\ y_1\end{array}\right]$

With

$\left[\begin{array}{c}{x}_2^{*}\\ {\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">y</figure-callout>}}_2^{*}\end{array}\right]=\left[\begin{array}{c}\mathrm{\&Delta;x}\\ \mathrm{\&Delta;y}\end{array}\right]+\left[\begin{array}{cc}1& \mathrm{\&alpha;}\\ -\mathrm{\&alpha;}& 1\end{array}\right]\&times;\left[\begin{array}{c}{x}_2\\ {\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">y</figure-callout>}}_2\end{array}\right]$

Wherein because rotation error is less, so be similar to cos α=1, sina=a arranged.

That comprehensively separates can get:

$\mathrm{\&alpha;}=1/2\&times;[\frac{(x_1^{*}-x_2^{*})-(x_1-x_2)}{y_1-{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">y</figure-callout>}}_2}+\frac{(y_1^{*}-{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000087508630000013.png"\; state="\{\{state\}\}">y</figure-callout>}}_2^{*})-(y_1-y_2)}{x_1-x_2}]$

$\mathrm{\&Delta;x}=x_1^{*}-x_1-y_1\&times;a$

$\mathrm{\&Delta;y}=y_1^{*}-y_1+x_1\&times;a$

With the side-play amount input of calculating gained zero inclined to one side framework, and before treating the Assembly part drilling, call the correction and the compensation that can realize frock and part error to be assembled.

Claims (2)

1. one kind is directed against the hybrid measurement method that part to be assembled is located in the aircraft components flexible assembly process; Said method comprises hybrid locating method whole strategy and three partial contents such as implementing procedure, drilling equipment coarse localization method and the accurate positioning mode of part to be assembled, it is characterized in that:

1) this method is mixed use laser tracker and photogrammetric instrumentation; Adopt laser tracker to carry out coarse localization; Photogrammetric instrumentation carries out pinpoint strategy, and the location of accessory to be installed in the aircraft components flexible assembly is divided into accurately location two steps of drilling equipment coarse localization and part to be assembled;

2) coarse localization of drilling equipment is accomplished the setting at zero point of workpiece in the drilling equipment; Set up the relativeness of aircraft components coordinate system and aircraft components physical location in Machinetool workpiece coordinate system, the digital-to-analogue, for the numerical control program of drilling equipment provides aircraft components position accurately;

3) part to be assembled accurately the location through at part to be assembled two ends, two positions of each preboring system accurately the hole as baseline positioning hole; In the drilling process; Photogrammetry system is through measure the physical location of baseline positioning hole on the part to be assembled and the deviation of theoretical position in real time; Thereby calculate the accurate position of part to be assembled, and offer Digit Control Machine Tool, accomplish the accurate position fixing process of part to be assembled.

2. the hybrid measurement localization method of part to be assembled is characterized in that specifically comprising the steps: in the aircraft components flexible assembly according to claim 1

Step 1: use laser tracker, measure the infrastructural frame of frock,, the physical location of frock and the physical location of digital-to-analogue are unified according to target ball position in the digital-to-analogue and the target ball position reading in the actual measurement;

Step 2: machine tool motion is easy to the position measured to certain, uses laser tracker that the lathe position of tool tip is measured;

Step 3: in the CATIA system, setting up coordinate figure is each point of measured value, and measurement data is imported in the CATIA system;

Step 4: according to general numerical-control processing method, select correct position,, and each change in coordinate axis direction and machine spindle direction unified, in CATIA, set up workpiece coordinate system with this as workpiece zero point;

Step 5: the operation lathe, read lathe at measured value;

Step 6: utilize measurement function among the CATIA, measure lathe position of tool tip point position in set workpiece coordinate of in the 3rd step, being set up;

Step 7: in lathe, be provided with zero partially, programming phases is at first called this zero unification that can accomplish lathe coordinate system and workpiece coordinate system partially;

Step 8: at part to be assembled two ends, two positions of each preboring system accurately the hole as baseline positioning hole, as the pinpoint benchmark of part to be assembled;

Step 9: the position of adopting photogrammetric instrumentation measuring basis locating hole;

Step 10: the deviation of calculating part physical location to be assembled and theoretical position according to the measurement result of photogrammetric instrumentation;

Step 11: realize the correction of deviation through the framework deflection.

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