CN108508848A - A kind of appraisal procedure of the Milling Process profile errors based on interpolation data - Google Patents
A kind of appraisal procedure of the Milling Process profile errors based on interpolation data Download PDFInfo
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- G05B19/41—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by interpolation, e.g. the computation of intermediate points between programmed end points to define the path to be followed and the rate of travel along that path
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Abstract
The appraisal procedure of the invention discloses a kind of Milling Process profile errors based on interpolation data, belongs to mismachining tolerance evaluation areas, includes the following steps：Step 1：Workpiece is designed into curved surface tri patch, obtains workpiece geometrical model；Step 2：Establish the geometrical model of cutter effective cutting shape；Step 3：Profile errors parallel computational model is built, the profile errors of each group are calculated based on interpolation data grouping parallel and is returned the result.The present invention each cutter location designing a model to be compared and calculate profile errors by cutter effective cutting shape and processing curve in interpolation data, profile errors calculating between each point is not in contact with, and the profile errors that each cutter location calculates can be corresponding with the cutter location position, it can be with the profile errors of each cutter location of parallel computation, it is more efficient, and the error for considering G code, digital control system and servo-drive system is more nearly during actual processing cutter with respect to the movement position of processing curve.
Description
Technical field
The invention belongs to mismachining tolerance evaluation areas, more particularly, to a kind of Milling Process wheel based on interpolation data
The appraisal procedure of wide error.
Background technology
In traditional mode of production, due to the presence of various mismachining tolerance factors, need to survey using three coordinates before processing in batching
It measures instrument and measures trial cut workpiece progress accuracy evaluation, ensure part processing precision.The shortcomings that three-coordinates measuring machine evaluation method is to need
First trial cut workpiece is wanted, three-coordinates measuring machine is reused and measures the profile errors after trial cut, it is of high cost, and measurement method efficiency
Low, time of measuring is long.
In addition to using measuring apparatus to evaluate trial cut profile errors, existing a kind of virtual appraisal procedure of profile errors, by adding
Work simulation software or d engine machining simulation process evaluate profile errors, such as in the CAM softwares such as UG and Verycut
There is such function, emulation is mainly processed by G code.During G code machining simulation, pass through cutter and workpiece
Blank asks friendship to calculate, and compares IPW (In Process Workpiece) and designs a model to obtain phantom error.Fig. 1 is illustrated
The basic procedure of machining profile error is measured by three-coordinates measuring machine, G code machining simulation.
G code is to ensure that design curved surface gives the Machining Instruction of contour accuracy, and packing density is small.And it is imitative based on G code
It is associated, the result of previous cutter location cutter and Billet Calculation that genuine method blank between front and back cutter point, which asks friendship to calculate,
It is that latter cutter location seeks the blank handed over and calculated, it is not possible to which independently of each other, emulation needs to carry out by the sequence of G code, it is difficult to accomplish
Parallel artificial.
And a three-coordinates measuring machine cannot accomplish parallel measurement, and separated G code is also difficult to simultaneously in machining simulation
Row emulation.
Invention content
For the disadvantages described above or Improvement requirement of the prior art, the present invention provides a kind of millings based on interpolation data to add
The appraisal procedure of work profile errors, its object is to according to cutter effective cutting shape, to the interpolation data of cutter location according to inserting
Benefit sequence is grouped, the cutter effective cutting shape error of parallel computation each group, is achieved in and is being improved the same of measurement efficiency
Shi Shixian machining simulations.
To achieve the above object, according to one aspect of the present invention, a kind of Milling Process based on interpolation data is provided
The appraisal procedure of profile errors, includes the following steps：
Step 1：Workpiece is designed into curved surface tri patch, obtains workpiece geometrical model；
Step 2：According to machining locus of the cutter on workpiece geometrical model, established on cutter tool coordinate system (X, Y,
Z), origin O is arranged in XOZ planes, Z axis along tool axis direction in cutter location position, tool motion speed；
The cutting edge of cutter includes three upper circular conical surface, transition anchor ring and lower circular conical surface parts, the effective cutting wheel of cutter
Exterior feature includes upper circular conical surface effective cutting shape SweepU,C, transition anchor ring effective cutting shape SweepT,CAnd lower circular conical surface has
Effect cutting profile SweepL,C：
Wherein, α be lower circular conical surface semi-cone angle, 90 ° of 0≤α ＜,
β be upper circular conical surface semi-cone angle, 90 ° of 0≤β ＜,
R1For transition annulus the circular arc portion centre of sphere to cutter shaft distance,
R2For the radius of the circular arc portion of transition annulus,
L is the total length of cutting edge,
H be transition annulus circular arc portion the centre of sphere to tool coordinate system OXY planes distance；
Vel.x is the component of tool speed in the X-axis direction,
Vel.y is the component of tool speed in the Y-axis direction；
Step 3：According to cutter effective cutting shape, interpolation data is grouped according to interpolation sequence, according to step 3.1
The cutter effective cutting shape error of~3.3 parallel computation each groups, step 3.1~3.3 are as follows：
The tool speed direction of step 3.1, the current cutter location of estimation；
Step 3.2, under different cutter locations, coordinate of the cutter effective cutting shape under tool coordinate system is transformed into
Workpiece coordinate system obtains the cutter effective cutting shape under workpiece coordinate system；
Step 3.3, according to the cutter effective cutting shape under workpiece coordinate system, calculate each cutter spacing in conjunction with cutter theoretical profile
The effective cutting shape error of point and to distinguish error pattern be to owe to cut, cross and cut or ideal processing.
Further, in step 3.2, the transition matrix R of tool coordinate system to workpiece coordinate systemtoolToWorkFor：
Wherein (x ', y ', z ') is the unit vector of workpiece coordinate system bottom tool velocity vector, and CL cuts for workpiece coordinate system
Site coordinate；
The temporal profile under workpiece coordinate system is solved by the transition matrix of tool coordinate system to workpiece coordinate system：
P=RtoolToWork·p′ (17)
P is the coordinate put on effective cutting shape under workpiece coordinate system, and p ' is on effective cutting shape under tool coordinate system
The coordinate of point, the cutter effective cutting shape under workpiece coordinate system is obtained by formula (12)~(14) and formula (17).
Further, in step 3.3, when putting milling, pass through the areas intersection point number n of cutter effective cutting shape and design curved surface
Point current cutter location of cutter, which is in, to be owed to cut, crosses and cut or ideal processing situation：
Belong to cutter as n=0 to owe to cut situation；Profile errors table is shown as cutter effective cutting shape and workpiece reason when owing to cut
Think the shortest distance ε between machining profile；
It was to cut situation as n=2；It crosses when cutting, cutter effective cutting shape and workpiece theory machining profile at least two
A intersection point P1、P2；Cross the part between two intersection points that profile errors measurement when cutting is cutter profile, i.e. P1P2Section curve with
Unidirectional Hausdorff distance between theoretical Tool in Cutting profile：
Wherein,
A indicates the P on cutter profile1P2Section curve, series of points a is separated by A1,a2,a3…am, it is A with set expression
={ a1,a2,a3…am}；B is workpiece theory machining profile curved surface, and workpiece theory machining profile curved surface is denoted as set B={ b1,b2,
b3…bk}；
It is ideal processing situation as n=1；Cutter effective cutting shape and workpiece theory machining profile are tangent at this time, wheel
Wide error is 0；
When side milling, cutter effective cutting shape is separated into point P1,P2,...,Pt, corresponding workpiece theoretical profile is discrete
At point P1′P2′,...,Pt', P1,P2,...,PtWith P1′P2′,...,Pt' correspond, vectorExist with workpiece theoretical profile
Point Pt' on normal vectorAngle beIfThen point Pt' place owes to cut, ifBe then cut, ifIt is then ideal processing situation.
Further, in step 2, three the upper circular cone of cutter, transition annulus and lower circular cone parts are under tool coordinate system
Geometric profile be shown below respectively：
CSC=CSU,C∪CST,C∪CSL,C (7)
Wherein,
CSU,CFor the geometric profile of circular conical surface on cutter,
CST,CFor the geometric profile of cutter transition anchor ring,
CSL,CFor the geometric profile of circular conical surface under cutter,
CSCFor the geometric profile of cutter whole surface.
Further, in step 2, during tool motion, the mathematical model of the effective cutting shape of cutter is under
Formula indicates：
Wherein,For the normal vector of tool surface each point,For the cutting direction of cutter；
The normal vector of tool surface each pointIncluding following component part：
Wherein,
nU,CFor the normal vector of each point on circular conical surface on cutter,
nT,CFor the normal vector of cutter each point on transition annulus,
nL,C(θ) is the normal vector of circular conical surface each point under cutter.
Further, in step 3.1, the method for estimating the tool speed direction of current cutter location is as follows：
For first cutter location P of interpolation0, select first three cutter location P0、P1、P2It is fitted circular arc, with P0In the circular arc
On cut arrowAs P0The tool speed direction at place, whereinWith vectorAngle is less than 180 °；
For the intermediate cutter location P of interpolationi, use previous cutter location Pi-1, current cutter location PiWith latter cutter location Pi+1Three
Point one circular arc of fitting, by current cutter location PiTangent line on the circular arc and vectorAngle is less than 180 ° of directionAs
Tool speed direction on the cutter location, i >=1；
For the last one cutter location of interpolation, it is fitted circular arc using last three cutter locations, by the last one cutter location
Tangential direction on the circular arcAs the tool speed direction on the cutter location.
Further, further include step 4：The effective cutting wheel of the corresponding cutter of each cutter location obtained according to step 3.3
Wide error and error pattern adjust G code, make cutter effective cutting shape error without departing from preset accuracy rating, to real
Existing machining simulation and simplation verification trial cut workpiece profile precision.
In general, the above technical scheme conceived by the present invention compared with prior art, can obtain following beneficial to effect
Fruit：
1, since the interpolation data of digital control system is to directly control the control instruction of each axis movement of lathe, packing density is big,
The present invention is compared in each cutter location of interpolation data by cutter effective cutting shape and designing a model for processing curve
Calculate profile errors, the profile errors calculating between each point is not in contact with, and the profile errors that each cutter location calculates can
It, can be with parallel computation with corresponding with the cutter location position；The present invention is based on the emulation of interpolation data to be more nearly actual processing mistake
Movement position of the cutter with respect to processing curve in journey, it is contemplated that G code, digital control system and servo-drive system error, compared to
In the prior art by the method for G code machining simulation, error considers more comprehensively.
2, consider the error before machine tooling the present invention is based on the method for interpolation data, and can with based on G
The method and three-coordinates measuring machine measurement method of code emulation are used in combination, to judge profile errors from which link,
Good compatibility；
3, the profile errors evaluation method based on interpolation data is not interrelated since the profile errors of each cutter location calculate,
So being very suitable for parallel computation.
Description of the drawings
Fig. 1 is that three based on the interpolation data kind profile of existing three-coordinates measuring machine, G code machining simulation and the present invention misses
Poor evaluation method flow comparison diagram；
Fig. 2 is swept volume and effective cutting shape schematic diagram；
Fig. 3 is the definition of seven parameter cutters, wherein 3 (a) is tool coordinate system schematic diagram, and 3 (b) is tool in cutting sword structure
Schematic diagram, 3 (c) are cutter parameters schematic diagram；
Fig. 4 is cutter effective cutting shape schematic diagram；
Fig. 5 is the present invention based on interpolation data parallel computation profile errors model；
Fig. 6 is intermediate cutter location (cutter location i.e. between first cutter location and the last one cutter location) knife of the present invention
Has directional velocity schematic diagram；
Fig. 7 is that first cutter location tool speed direction of the present invention determines schematic diagram；
Fig. 8 is that the last one cutter location tool speed direction of the present invention determines schematic diagram；
Fig. 9 is that the deficient profile errors for cutting situation of the present invention calculate schematic diagram；
Figure 10 is that the mistake of the present invention cuts the profile errors calculating schematic diagram of situation；
The profile errors of Figure 11 ideal situation situations calculate schematic diagram；
Figure 12 is the single cutter location profile errors calculation flow chart of point milling process of the present invention；
Figure 13 is the Flank machining schematic diagram of the present invention；
Figure 14 is the side milling error distribution schematic diagram of the present invention；
Figure 15 is that the point-by-point profile errors of interpolation data of the present invention calculate schematic diagram；
Figure 16 is the generation process schematic of interpolation data.
Specific implementation mode
In order to make the purpose , technical scheme and advantage of the present invention be clearer, with reference to the accompanying drawings and embodiments, right
The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and
It is not used in the restriction present invention.As long as in addition, technical characteristic involved in the various embodiments of the present invention described below
It does not constitute a conflict with each other and can be combined with each other.
Before the formal introduction present invention, several terms are first introduced：
Interpolation data：
In NC Machining Process, the machining code that digital control system is inputted is the G that CAD/CAM system postpositive disposal obtains
Code, but G code cannot directly control lathe each axis servo-drive system motor rotation, thus digital control system need to G code into
Row interpolation and speed planning obtain the director data for controlling each motor movement, and by director data, each axis moves to specified
Position, the present invention used in interpolation data be exactly the physical location number fed back in each axis servo motor of each interpolation cycle
According to.The generation process of interpolation data is as shown in figure 16.
The concept of cutter effective cutting shape：
When a solid carries out rigid motion, the region on all the points Special composition on its outer surface profile is known as
Swept volume.In digital control processing, when cutter processes a blank along Cutting trajectory, part that this workpiece is processed
It is exactly cutter swept volume.This process can be regarded as some profile of cutter outer surface along cutter path to blank
It is cut, and the profile of this cutter outer surface is defined as the effective cutting shape of cutter, as shown in Figure 2.
Hausdorff distance (HD) basic definition is as follows：
A={ a1,a2,a3…am, B={ b1,b2,b3…bkRespectively indicate two finite points set.HD is defined as
H (A, B)=max (h (A, B), h (B, A)) (1)
H (A, B) is known as the unidirectional Hausdorff distance from set A~B in formula, is defined as
H (B, A) is known as the unidirectional Hausdorff distance from set B~A, is defined as
The concept of parallel computation：
Parallel computation (Parallel Computing) refers to solving the mistake of computational problem using a variety of computing resources simultaneously
Journey is a kind of effective means for improving computer system calculating speed and processing capacity.Its basic thought is with multiple processing
Device carrys out Cooperative Solving same problem, i.e., the problem of being solved resolves into several parts, and each section is independent by one
Reason machine carrys out parallel computation.Parallel computation requires technology contents not related between each other, is segmented into multi-group data while calculating.
A kind of key step of the appraisal procedure of the Milling Process profile errors based on interpolation data of the present invention is described below,
Fig. 1 is please referred to, step of the invention is as follows：
Step 1：Prepare data, including：Acquire the interpolation data in digital control system process；Part model it is discrete,
Workpiece is designed into curved surface tri patch；Process tool parameter is read from digital control system.Wherein, interpolation data is acquired, reading adds
Work cutter parameters can also be needed in subsequent step with then execution in real time.
Step 2：Establish the geometrical model of cutter effective cutting shape
According to the definition of APT cutters, one is determined universal cutter by seven parameters.For the ease of the description of cutter, in knife
Tool coordinate system (X, Y, Z) is established on tool, so that tool coordinate is met origin O in cutter location position, tool motion speed is flat in XOZ
Face, Z is along tool axis direction.By taking APT cutters as an example, definition mode such as Fig. 3 (a), 3 (b), 3 (c) are shown.
The wherein parameter of cutter：
α be cutter bottom semi-cone angle, 90 ° of 0≤α ＜,
β be cutter blade semi-cone angle, 90 ° of 0≤β ＜,
R1For cutter transition annulus the circular arc portion centre of sphere to cutter shaft distance,
R2For the radius of the circular arc portion of cutter transition annulus,
L is the total length of tool in cutting sword,
H be cutter transition annulus the circular arc portion centre of sphere to tool coordinate system OXY planes distance.
One universal cutter is made of three parts：Upper circular cone, transition annulus, lower circular cone.Thus milling cutter three parts are obtained
Geometric description under tool coordinate system is shown below respectively.
CSC=CSU,C∪CST,C∪CSL,C (7)
Wherein a ∈ [0,1], b ∈ [0,1],θ ∈ [0,2 π], subscript C indicate tool coordinate system, under
Circular cone in U expressions is marked, subscript T indicates transition annulus, and subscript L indicates lower circular cone, so CSU,CFor circular conical surface on cutter, CST,CFor
Cutter transition anchor ring, CSL,CFor circular conical surface under cutter, CSCFor cutter whole surface, cutter whole surface is by upper circular conical surface, mistake
Cross anchor ring, lower circular conical surface composition.
During tool motion, the mathematical model of the effective cutting shape of cutter can be obtained by following formula：
WhereinFor the normal vector of tool surface each point,For the cutting direction of cutter.
According to tool surface CSC(s) mathematical expression (7) knows, the normal vector of tool surfaceIt can be expressed as：
Wherein nU,CFor the normal vector of each point on circular conical surface on cutter, nT,CFor the normal direction of cutter each point on transition annulus
Amount, nL,C(θ) is the normal vector of circular conical surface each point under cutter.
So obtaining moving tool by formula (8)~(11) and being respectively in the mathematical expression of each section of effective cutting shape：
Wherein a ∈ [0,1], b ∈ [0,1],SweepU,CFor effective cutting wheel of circular conical surface on cutter
Exterior feature, SweepT,CFor the effective cutting shape of cutter transition anchor ring, SweepL,CFor the effective cutting shape of circular conical surface under cutter.
The effective cutting shape of circular conical surface and lower circular conical surface on cutter can be obtained by the value range of a and b.Vel.x is tool speed
Component in the X-axis direction, Vel.y are the component of tool speed in the Y-axis direction, so when known to Tool in Cutting direction,
For eachValue can calculate SweepT,COn a point.Cutter effective cutting shape is by circular conical surface on cutter
Effective cutting shape (SweepU,C), the effective cutting shape (Sweep of transition anchor ringT,C) and lower circular conical surface effective cutting
Profile (SweepL,C) composition, so as to establish the complete model of cutter effective cutting shape, such as Fig. 4 under tool coordinate system
It is shown.
Step 3：Build profile errors parallel computational model
Since the precision of interpolation data is high, data volume is big, and the present invention calculates wheel using cutter effective cutting shape
Wide error is not associated with necessarily between cutter location, therefore improves efficiency according to the parallel computation of step 3.1~3.4.By to interpolation
Data are grouped, and using CPU, GPU or the profile errors of computer cluster parallel computation each group and are returned the result.Fig. 5 is
The model of interpolation data parallel computation.The step of parallel computation, is as follows：
The directional velocity of step 3.1, the current cutter location of estimation
Due to interpolated point include be tool motion process discrete cutter location, there is no tool motion directional velocity, can be with
Previous cutter location P can be used for example in the tool speed direction that current cutter location is estimated by a variety of methodsi-1, current cutter location
PiWith latter cutter location Pi+13 points of one circular arcs of fitting calculate tool motion directional velocity, and as shown in 6 figures, circular arc is in current cutter spacing
Point tangent line on vectorAngle is less than 180 ° of directionFor the directional velocity of the cutter location.Similarly in interpolated point first
A position uses first three cutter location P0、P1、P2It is fitted circular arc, as shown in 7 figures, velocity vector is circular arc in first cutter location
P0Cut arrowWith vectorAngle is less than 180 °.The last one position is fitted circular arc, speed side using last three points
Arrow is cut on the last one point to for circular arc, as shown in 8 figures.
Step 3.2, the conversion of cutter effective cutting shape coordinate
The model for the cutter effective cutting shape established in step 2 be under tool coordinate system, and processing curve design
Model is in workpiece coordinate system, so under different cutter locations, effective cutting shape coordinate transform to workpiece coordinate system.
Because tool coordinate origin O is in cutter location position, tool motion speed is in XOZ planes, and Z is along tool axis side
To so transition matrix R of the tool coordinate to workpiece coordinatetoolToWorkFor：
Wherein (x ', y ', z ') is the unit vector of workpiece coordinate system bottom tool velocity vector, and CL cuts for workpiece coordinate system
Site coordinate.
The temporal profile under workpiece coordinate system is solved by the transition matrix of tool coordinate system to workpiece coordinate system：
P=RtoolToWork·p′ (17)
P is the coordinate put on effective cutting shape under workpiece coordinate system, and p ' is on effective cutting shape under tool coordinate system
The coordinate of point, the effective cutting shape under workpiece coordinate system can be obtained by formula (12)-(14) and formula (17).
The calculating of step 3.3 profile errors
Point milling situation, owe to cut, cross cut, three kinds of situations of ideal processing, pass through cutter effective cutting shape and design curved surface
Intersection point number n belong to any situation to distinguish：
Belong to cutter as n=0 to owe to cut situation.Profile errors table is shown as cutter effective cutting shape and workpiece reason when owing to cut
The shortest distance ε of property machining profile, as shown in Figure 9.
It was to cut situation as n=2.It crosses when cutting, cutter effective cutting shape and workpiece theory machining profile at least two
A intersection point, as shown in Figure 10, there are two intersection point P with desired profile for cutter profile1, P2.It is cutter to cross profile errors when cutting and weigh
Part (the i.e. P between two intersection points of profile1P2Section curve) with the unidirectional Hausdorff distance of theoretical profile, at this time error mark
It was denoted as and cut, had：
Wherein A is the curve P on cutter profile1P2, A is separated into series of points a1,a2,a3…am, use set expression
For A={ a1,a2,a3…am, similarly, workpiece theoretical profile profile is denoted as set B={ b1,b2,b3…bk}。
It is ideal processing situation as n=1.Cutter effective cutting shape and workpiece theory machining profile are tangent at this time, wheel
It is 0 that wide error, which is weighed, as shown in figure 11.Figure 12 is the point single cutter location profile errors calculation flow chart of milling process.
The theoretically line contact of the side edge of cutter and workpiece when side milling, as shown in figure 13, so side milling situation letter
Turn to a distance from workpiece surface less than tool radius cutter effective cutting shape side edge and workpiece surface range distribution, first
Cutter effective cutting shape is separated into a little, then seeks the shortest distance of discrete point and workpiece theoretical profile, as shown in figure 14 respectively from
The distance of scatterplot to workpiece theoretical profile is respectively P1P1', P2P2' ..., PtPt', point PnIn the side of cutter effective cutting shape
On sword, point Pt' on theoretical curved surface profile, vectorWith theoretical curved surface profile in point Pn' on normal vectorAngle beIfThen the error symbol of the point be owe to cut, ifIt was then
It cuts, ifIt is then ideal processing situation.
Profile errors are calculated by above step in each cutter location by continuous interpolation data, the wheel of curved surface can be obtained
Wide virtual error calculates, and calculating process is as shown in figure 15.
Step 4：Profile errors are assessed
After the profile errors of all interpolated points of parallel computation, the corresponding profile errors of each cutter location are exported, and to defeated
Go out profile errors and show that each cutter location is owed to cut or cross the case where cutting by the form of chart, such as is shown and processed using chromatogram
The profile errors situation of each point on curved design model.There are the G generations of the overproof position of precision by the evaluation adjustment of profile errors
Code makes profile errors without departing from accuracy rating, reaches the effect of machining simulation and three-dimensional coordinates measurement trial cut part verification contour accuracy
Fruit.
As it will be easily appreciated by one skilled in the art that the foregoing is merely illustrative of the preferred embodiments of the present invention, not to
The limitation present invention, all within the spirits and principles of the present invention made by all any modification, equivalent and improvement etc., should all include
Within protection scope of the present invention.
Claims (7)
1. a kind of appraisal procedure of the Milling Process profile errors based on interpolation data, which is characterized in that include the following steps：
Step 1：Workpiece is designed into curved surface tri patch, obtains workpiece geometrical model；
Step 2：According to machining locus of the cutter on workpiece geometrical model, tool coordinate system (X, Y, Z) is established on cutter, it is former
Point O is arranged in XOZ planes, Z axis along tool axis direction in cutter location position, tool motion speed；
The cutting edge of cutter includes three upper circular conical surface, transition anchor ring and lower circular conical surface parts, cutter effective cutting shape packet
Include circular conical surface effective cutting shape SweepU,C, transition anchor ring effective cutting shape SweepT,CAnd lower circular conical surface is effectively cut
Cut profile SweepL,C：
Wherein, α be lower circular conical surface semi-cone angle, 90 ° of 0≤α ＜,
β be upper circular conical surface semi-cone angle, 90 ° of 0≤β ＜,
R1For transition annulus the circular arc portion centre of sphere to cutter shaft distance,
R2For the radius of the circular arc portion of transition annulus,
L is the total length of cutting edge,
H be transition annulus circular arc portion the centre of sphere to tool coordinate system OXY planes distance；
Vel.x is the component of tool speed in the X-axis direction,
Vel.y is the component of tool speed in the Y-axis direction；
Step 3：According to cutter effective cutting shape, interpolation data is grouped according to interpolation sequence, according to step 3.1~
The cutter effective cutting shape error of 3.3 parallel computation each groups, step 3.1~3.3 are as follows：
The tool speed direction of step 3.1, the current cutter location of estimation；
Step 3.2, under different cutter locations, coordinate of the cutter effective cutting shape under tool coordinate system is transformed into workpiece
Coordinate system obtains the cutter effective cutting shape under workpiece coordinate system；
Step 3.3, according to the cutter effective cutting shape under workpiece coordinate system, calculate each cutter location in conjunction with cutter theoretical profile
Effective cutting shape error and to distinguish error pattern be to owe to cut, cross and cut or ideal processing.
2. a kind of appraisal procedure of the Milling Process profile errors based on interpolation data as described in claim 1, feature exist
In, in step 3.2, the transition matrix R of tool coordinate system to workpiece coordinate systemtoolToWorkFor：
Wherein (x ', y ', z ') is the unit vector of workpiece coordinate system bottom tool velocity vector, and CL is cutter location under workpiece coordinate system
Coordinate；
The temporal profile under workpiece coordinate system is solved by the transition matrix of tool coordinate system to workpiece coordinate system：
P=RtoolToWork·p′ (17)
P is the coordinate put on effective cutting shape under workpiece coordinate system, and p ' is to be put on effective cutting shape under tool coordinate system
Coordinate obtains the cutter effective cutting shape under workpiece coordinate system by formula (12)~(14) and formula (17).
3. a kind of appraisal procedure of the Milling Process profile errors based on interpolation data as claimed in claim 2, feature exist
In in step 3.3, when putting milling, the intersection point number n for passing through cutter effective cutting shape and design curved surface distinguishes the current cutter spacing of cutter
Point, which is in, to be owed to cut, crosses and cut still ideal processing situation：
Belong to cutter as n=0 to owe to cut situation；Profile errors table is shown as cutter effective cutting shape and adds with workpiece ideal when owing to cut
Shortest distance ε between work profile；
It was to cut situation as n=2；It crosses when cutting, at least there are two hand over workpiece theory machining profile for cutter effective cutting shape
Point P1、P2；Cross the part between two intersection points that profile errors measurement when cutting is cutter profile, i.e. P1P2Section curve and theory
Unidirectional Hausdorff distance between Tool in Cutting profile：
Wherein,
A indicates the P on cutter profile1P2Section curve, series of points a is separated by A1,a2,a3…am, it is A=with set expression
{a1,a2,a3…am}；B is workpiece theory machining profile curved surface, and workpiece theory machining profile curved surface is denoted as set B={ b1,b2,
b3…bk}；
It is ideal processing situation as n=1；Cutter effective cutting shape and workpiece theory machining profile are tangent at this time, and profile misses
Difference is 0；
When side milling, cutter effective cutting shape is separated into point P1,P2,...,Pt, corresponding workpiece theoretical profile is separated into a little
P1′P2′,...,Pt', P1,P2,...,PtWith P1′P2′,...,Pt' correspond, vectorWith workpiece theoretical profile in point
Pt' on normal vectorAngle beIfThen point Pt' place owes to cut, ifBe then cut, ifIt is then ideal processing situation.
4. a kind of assessment side of Milling Process profile errors based on interpolation data as described in claims 1 to 3 any one
Method, which is characterized in that in step 2, the upper circular cone of cutter, transition annulus and three parts of lower circular cone are several under tool coordinate system
What profile is shown below respectively：
CSC=CSU,C∪CST,C∪CSL,C (7)
Wherein,
CSU,CFor the geometric profile of circular conical surface on cutter,
CST,CFor the geometric profile of cutter transition anchor ring,
CSL,CFor the geometric profile of circular conical surface under cutter,
CSCFor the geometric profile of cutter whole surface.
5. a kind of appraisal procedure of the Milling Process profile errors based on interpolation data as claimed in claim 4, feature exist
In in step 2, during tool motion, the mathematical model of the effective cutting shape of cutter is expressed from the next：
Wherein,For the normal vector of tool surface each point,For the cutting direction of cutter；
The normal vector of tool surface each pointIncluding following component part：
Wherein,
nU,CFor the normal vector of each point on circular conical surface on cutter,
nT,CFor the normal vector of cutter each point on transition annulus,
nL,C(θ) is the normal vector of circular conical surface each point under cutter.
6. a kind of assessment side of Milling Process profile errors based on interpolation data as described in claims 1 to 3 any one
Method, which is characterized in that in step 3.1, the method for estimating the tool speed direction of current cutter location is as follows：
For first cutter location P of interpolation0, select first three cutter location P0、P1、P2It is fitted circular arc, with P0On the circular arc
Cut arrowAs P0The tool speed direction at place, whereinWith vectorAngle is less than 180 °；
For the intermediate cutter location P of interpolationi, use previous cutter location Pi-1, current cutter location PiWith latter cutter location Pi+13 points quasi-
Unify circular arc, by current cutter location PiTangent line on the circular arc and vectorAngle is less than 180 ° of directionAs the knife
Tool speed direction on site, i >=1；
For the last one cutter location of interpolation, it is fitted circular arc using last three cutter locations, by the last one cutter location at this
Tangential direction on circular arcAs the tool speed direction on the cutter location.
7. a kind of assessment side of Milling Process profile errors based on interpolation data as described in claims 1 to 3 any one
Method, which is characterized in that further include step 4：The corresponding cutter effective cutting shape of each cutter location obtained according to step 3.3 misses
Difference and error pattern adjust G code, make cutter effective cutting shape error without departing from preset accuracy rating, add to realize
Work emulates and simplation verification trial cut workpiece profile precision.
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