# Form the error detects technical research

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The area between the face of two packets of sth resembling a net of the ball of 200mm, ball heart of Zhu Qiu should be located in on the side that has figure of academic and correct geometry. The ideal outline when the element that be measured is relatively fiducial when asking without the position, attribute appearance common difference; Be opposite when the ideal outline of the element that be measured fiducial when the position asks, attribute positional common difference [1] . Digitlization detects face outline spends an error: Be measured in product CAD model academic measurement point is recovered on the face, will get model the dot on the face academic data and law arrow direction, the editor becomes document of text of an academic data, apply numerical control to measure vector to nod a program to undertake metrical to spare parts outline again, gain real point, through real point nod with theory undertake comparative, whether does the total error that judgement is measured to choose an edge vector way satisfy tolerancepublic errand to ask [2] . Its outline spends error assess is the magic art that along the face that be measured every choose to X, Y, Z 3 direction is integrated assess, use formula: Fi=I × (Xi-xi)+J × (Yi-yi)+K × (Zi-zi) (1) in type, i, J, K is X, Y, Z 3 respectively vector heft of direction, xi, Yi, Zi is value of each bits of actual coordinate, xi, Yi, Zi is value of each bits of academic coordinate. Present outline is spent when be appearance error, can be worth according to the coordinate of measurement point, undertake best-fitting with curved surface, achieve the groove of all measurement point, undertake nodding an assess finally. Present outline is spent when be position error, can be worth according to the coordinate of measurement point, in place given on positional direction (what what tag is fiducial on) cannot undertake translation is mixed rotate, the translation that random can undertake on other way and rotate, till all dots achieve groove, undertake nodding an assess finally. Outline spends tolerancepublic errand to if the graph is shown 2 times,be analysed. If be opposite below workpiece undertakes detecting: The overall arrangement that orders according to curved surface feature asks, digit is nodded to occupy in the theory that the position that be measured draws on product model. Those who use vector site is automatic detect the function undertakes be metricaled actually to these dots, with formula (1) the total error that computation gives a point, still can pass the coordinate cost that watchs every real measurement point, analyse a photograph of the outline that be measured the deviate condition to ideal outline. Nextpage line outline spends detect technical research is current, when doing complex line outline to spend an evaluation, often use Newtonian iterative method to wait for those who optimize algorithmic computation to be measured to order academic contour line to be apart from a heart recently, computational process is complex, some circumstances cannot seek solution even. When be being formed by many expression when whole outline curve additionally, still need to judge the outline expression of correspondence of place of the spot that be measured first; To already giving out a series of model the outline that is worth a dot often uses the function such as batten 3 times to plan to add up to academic outline, after the academic outline expression that receives planning to close again the method before the basis, the rough sketch that computation gives to be measured to nod spends an error, plan to add up to a process to be able to have precision loss necessarily among them [3] . Spend the trival sex of assessment technique and limitation in the light of eye front outline, the article put forward a kind of outline that is based on disperse dot to spend evaluation algorithm, this algorithmic and main computation nods the least space of the dot, the dot with avoided relatively difficult arrives irregular curve is the smallest the computation of the distance. Line outline spends an error is to point to be measured actually contour line is right the variation of academic contour line. Spend the definition of the error by outline, the basiccest assess principle need is contented most Xiaobao contains area principle. Most packet look area is to show by 2 parallel curve is included when real profile line, have the smallest breadth include area. In the assess that online outline spends an error, any methods should be basic principle with this principle, but because use this principle directly relatively difficult, often use the approximate algorithm such as least square. The evaluation basis that line outline spends has without fiducial can divide the line outline that be spent to have the line outline of fiducial requirement and does not have fiducial requirement to spend. The article is with the line outline of fiducial requirement is spent exemple, discuss the outline that is based on disperse dot to spend algorithm, likewise applicable to be being spent without the line outline of fiducial requirement. Spend a requirement to be in only on aleatoric direction when assess when line outline, it is basic and identical that the demand that its gauge actually is spent with face outline, but spend a requirement to go up and set the assess inside length in aleatoric direction when line outline when, its measure a requirement actually to be spent with face outline detect have certain difference. Check evaluation is time, must undertake controlling to the length of aleatoric curve, inside formulary length assess line outline is spent, such requirement, some more loose than stipulating length assess asks relative to tolerancepublic errand. The article basically discusses to go up in aleatoric direction, the means that stipulates outline of line of the assess inside length is spent. The academic coordinate value that nods according to gets disperse and academic law vector, combine 3 coordinate to measure of machine measure bit of function automatically, all academic disperse the dot undertakes detecting automatically, get the real measured value of these academic disperse dots. Use disperse to nod the assess that undertakes line outline is spent, be about to the disperse dot P of academic outline and the disperse dot Q of the outline that be measured undertake contrasting computational. Above all, to each Q, all search to be apart from recent dot with its in P. Next, computation gives the D of the least space of every Q correspondence. Finally, computation gives the maximum Dmax in series, be measured namely the line outline of outline spends an error. If pursue 3 in spare parts, line outline is tagged to spend on curved surface, in sill case, line outline spends a requirement to be measured on direction of either of the edge on curved surface and either 200mm length, line outline spends tolerancepublic errand for 0.

200mm, at present CMM measures software to just be spent in outline of line of the assess inside some plane, cannot assess spends an error along the line outline of aleatoric direction. Outline of CMM check line is spent is the coordinate value that goes up each a little bit through slotted line, obtain an error to be worth through data processing, make qualification conclusion. The line outline that wants way of random of assess edge curved surface spends an error to whether accord with precision requirement, must weave program of appropriative data processing. Hypothesis some curve has A, B, C 3 measurement point, computational A, B, C the error 3 o'clock, if the error is more than tolerancepublic errand unqualified, if be less than a qualification. However, measure check the number to cannot decide beforehand commonly, accordingly, can use another kind of equivalent method, use relative at 2 o'clock method to replace namely at 3 o'clock or more chooses relative way, for example (the error 3 o'clock is worth A, B, C) is for certain (A, B) , (A, C) , (one of value of error of group of B, C)3, if have one unqualified among them, unqualified, if all qualification is eligible. There were countless planes at 2 o'clock through random, and every plane and curved surface have 1 to cross a line, because this cannot decide two distances that are in a curve, can replace curvilinear distance with the linear distance 2 o'clock only, can spend to line outline not only so control better, and make algorithm has feasibility. Line outline degree occupies evaluation program advocate the interface is shown 4 times like the graph. Graph degree of 4 lines outline occupies evaluation program advocate compound position spends the interface detect the technology studies compound position spent tolerancepublic errand to offer fixed position of diagnostic measure group and diagnostic dimension to be in inter block correlation (the tie rotates and translation) on the means that uses the position to spend tolerancepublic errand. The requirement is made clear through using compound feature to dominate draw a frame round. Spend to this kind of position, positional sign is filled only be opposite namely all level sash is applicable. Among them the sash of every whole level in diagnostic control casing can be checked respectively. Nextpage compound position is spent in include group of fixed position public errand to take casing and feature relevant public errand leads draw a frame round. Peace rotates fiducially to move at the regulation related the tie of casing of tolerancepublic errand belt of casing of belt of public errand of group fixed position. Served as a group of set gauge to decide larger position to spend tolerancepublic errand to diagnostic measure series. Applicable standard feature should be pressed given priority is referenced, have the effect of will academic true measure and connection of photograph of fiducial and referenced casing. Casing of tolerancepublic errand belt is related the feature by the feature relevant control. They controlled each feature dimension to be in inter block (the relation of feature and feature) minor position spends tolerancepublic errand. Basic measure can be used at public errand of group fixed position to lead draw a frame round, and do not apply to a feature relevant public errand leads draw a frame round. When next sash that dominate draw a frame round when compound feature did not stipulate reference is fiducial, casing of tolerancepublic errand belt can be in related the feature by belt of public errand of group fixed position casing is built and peace rotates to move freely inside pilot border; If issueing sash to set fiducial, casing of tolerancepublic errand belt can be in related their control feature by belt of public errand of group fixed position casing is built and the photograph inside pilot border about rotating fiducially; When stipulating standard feature is referenced, the position spends casing most above when the one or more standard feature that sash provides, answer to restrain the whirl of coordinate department by identical priority. Compound public errand has 2 or many sash. Every sash builds tolerancepublic errand to take and the tie shows any reference inside sash are fiducial. The reference inside the first sash is fiducial build all and applicable rotate and consult at place related translation tie fiducial. The 2nd with the reference inside follow-up sash fiducial build only rotate consult at place related the tie fiducial. When the reference inside sash fiducial and vacant express to did not pass these sash to build rotate and translation tie. Compound to containing position spends the application of the team feature of tolerancepublic errand, establish zones of group of fixed position public errand through the first sash, relevant public errand takes alone feature to be built through each follow-up sash. Measure opening position to spend for example on sash is the photograph is fiducial to A, B, C the position is spent, tolerancepublic errand asks to be φ 0.

25; Sill case is the photograph is fiducial to A, B, C the position is spent, tolerancepublic errand asks to be φ 0.

10; To going up sash position is spent when detecting, press A, B, C fiducial after building coordinate to fasten, according to its diagnostic element and fiducial the relation between, spend to the position directly undertake evaluating, the photograph is fiducial to A, B, C do not allow to undertake peace moves gyral. When detecting to issueing sash position to spend, press A, B, C fiducial after building coordinate to fasten, according to its dimension concerns between diagnostic element, contrapuntal buy is spent undertake evaluating, the photograph is fiducial to A, B, C do not allow to undertake gyral. Tolerancepublic errand belt: If pursue 5 in the symbolic φ that expresses a diameter is contained before tolerancepublic errand value, criterion the figure that this position spends tolerancepublic errand to take is cylinder; The position alignment error that the dot of two upright limits through measuring aperture basically is when be being measured will control the position of aperture to spend, when the position alignment error that nods when the two limits of aperture is eligible, the position of aperture spends qualification. In assess when its error, the academic coordinate that sets each the centre of a circle is Oi(xi, yi, zi) , the actual coordinate of the centre of a circle is Oi(xi, yi Zi) , criterion the position alignment error that two upright limits burn each hole expresses to be =2(Xixi)2+ (Yiyi)2. Below illustrate, compound position spends detect method. Detect the process is as follows: Measure 1: the part that be measured appropriate fixed position measures the workbench of machine to go up in 3 coordinate (CMM working face) , if pursue,5 are shown. Measure 2: Graph 5 medium spare partses are to use compound position to spend position of control aperture group, spend the niche that dominates aperture group jointly by 2 positions namely, sash brings a demand for aperture group public errand on, 4 φ 0.

The public errand of 25mm is taken, posture of frame of its geometry picture is firm to fiducial A, B, C; Sill case is the further requirement between each aperture, 4 φ 0.

The public errand of 12mm is taken, frame of its geometry picture only the photograph is directional to fiducial A, to A, B, C 3 fiducial ask without fixed position, accordingly it can be inside certain limits random is mobile. The actual axes of aperture must accord with the position of fluctuation sash to spend a requirement at the same time, can be located in φ only namely 0.

25mm and φ 0.

12mm2 cylindrical inside the jackknife part that tolerancepublic errand takes, if pursue,6 are shown. Nextpage measure 3: Build Z axis way with fiducial A, build X axis way with fiducial B, and define fiducial A, B, C 3 the nodical X=0 of the face, Y=0, Z=0, this coordinate fastens department of the coordinate that it is 1# . Measure 4: Undertake metrical to columnar outline, the real point that goes up with every columnar face respectively plan to synthesize cylinder, plan to add up to 4 cylinder in all. Measure 5: Tectonic cylinder two end panel, intersect the cylinder that be measured with two termination plane respectively, get 8 limits are nodded. Measure 6: In 1# coordinate the department falls, the coordinate value that nods through observing every limit is OK cent separate out is measured aperture is opposite at standard deviate position, the actual place that chooses with every limit and academic position seek a space, of this distance 2 times it is every aperture that be measured relative to the position alignment error at fiducial A, B, C. Beg sill case position alignment error, sill case has position alignment error to be measured fiducially, if pursue,6 are shown. Measure 7: In 1# coordinate the department falls, build X axis way with 1 aperture and 2 opening tectonic line, define 1 aperture X=10, Y=20, this coordinate fastens department of the coordinate that it is 2# . Measure 8: In 2# coordinate the department falls, the coordinate value that nods through observing every limit is OK cent separate out is measured the deviate condition between Kong Zhi, the actual place that chooses with every limit and academic position seek a space, of this distance 2 times it is the position alignment error between every Kong Zhi that be measured. When instantly sash position spends out of tolerance, going up below the premise that sash position spends qualification, OK and aleatoric translation or rotate 2# coordinate is, till sill case position is spent,achieve groove till. Should go up to sash position is spent and issue sash position to spend detect below eligible circumstance, this are compound the position spends qualification, otherwise this are compound the position is spent unqualified. Other position is spent detect the other position with technical commonly used research is spent coaxial is spent, symmetry, parallelism, verticality, gradient, use 3 coordinate to measure machine the principle that has digitlizing detecting is the form these abstraction the error is measured, changeover is assess of corresponding dot position control, spend algorithm according to its corresponding position, computation reachs corresponding position spends assess result. Be like the measurement to symmetry: Symmetry is to state element of semmetry of on the spare parts two centers maintains be in with the state inside plane. Symmetry public errand is to be measured what element allows relative to fiducial element place most upheaval quantity. Symmetrical structure element is very much on the spare parts, be like the two flank of keyway, v chamfer, the two flank of connecting rod slide block and swing tower surface [5] . Below illustrate, detect in what 3 coordinate measure the symmetry on machine. (1) does tolerancepublic errand take: ? Hesitating Hun correct refineds of mu of of the She nationality of of simian deficient skirt of boundless and indistinct of simian mother-in-law of Suo of correct of natrium of Gu Hang of miscellaneous joke washing with watercolors is bowed with hands clasped to ah? of Scandium of Jia .

The area between the two parallel plane of 1mm, if pursue,7 are shown. (2) detect: ? of deceive of of Xi of Mou Jizhong spins astounded of Jian of an ancient small-mouthed wine vessel of grandma of Ba adept P exuviate is salty rise abruptly " ? of street of writing of approach of Man of if of of Hu of ＜ of Qian of of emperor of lot of Zhang of Mu Li of hesitating pay department aing concubine of an emperor holding sb in respectful awe: the part that be measured appropriate fixed position measures the workbench of machine to go up in 3 coordinate (CMM working face) , if pursue,8 are shown. Measure 2: In fiducial A (fiducial center is planar) on build Z axis way, and definition A fiducial Z=0. Measure 3: The outline on undertakes metrical, gain real point. Measure 4: According to the kind that tolerancepublic errand takes, the Z of these dots can allocate to tolerancepublic errand for: + 0.

05/-0.

05. Measure 5: Nod actually through observing every Z can judge symmetry to coordinate value eligible, still can analyse a plane that be measured the deviate condition of opposite datum plane. The method that spends in the light of compound face outline and compound position are spent basic and identical, advocate if spend face outline changeover be what vector nods,detect, the application in measuring coordinate department to build in the light of fiducial tagging and compound position are spent identical. The concept that conclusion digitlizes is applied by extensive promotion in machining manufacturing industry, use simply measure machine software function to undertake the product detects, although OK and mensurable reach measure an outcome, but its measure a result not to facilitate the following craft is analysed. Research body tolerancepublic errand digitlization detects, put forward to use disperse to nod check to evaluate boarding the method of the error, intuitionistic report gives in kind the quality of whole form and structure and deviate direction, facilitate not only the repair of reject, and the improvement that can promote technique, have potential economic benefits. Complex form the error applies extensively already in international design concept, our country also is using a few complex form in newest design error, but be aimed at a little complex form the concept of the error, still do not have very clear explanation, for example, compound face outline is spent, the line outline that provides the assess inside limits is spent etc, need us to have research study, know its concept and assess method deep, excogitate its to detect accordingly thereby method. CNC Milling