CN102789196B - Method for optimizing integral structure configuration of special machine tool based on post information - Google Patents

Abstract

The invention provides a method for optimizing the integral structure configuration of a special machine tool based on post information. The method comprises the following steps: generating free-form machining post information by utilizing numerical control programming software according to a specific machine tool structure and a corresponding numerical control system; extracting the post information by utilizing C programming language, resolving control words in G codes according to letter address, and storing obtained displacement and feed speed information into a structural body variable; calculating machining time between cutter location points according to the principle of a multi-coordinate machine tool multiaxis interpolator; and calculating speed, acceleration and acceleration distribution of each axis by utilizing a difference method; performing kinematic simulation on a three-translation shaft by utilizing ADAMS, and outputting the distribution of acceleration of each axis along with the position of the free-form surface; calculating weighting acceleration of each axis; calculating inertia force corresponding to the maximum acceleration and the weighting acceleration, respectively, comparing relationship in magnitude of the inertia force of each axis, analyzing the reasonableness of the original machine tool structure configuration and putting forward an optimized integral structure configuration scheme of the machine tool.

Description

A kind of special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information

Technical field the present invention relates to a kind of special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information.Belong to numerical control machine tool technique field.

Background technology changes complex parts processing greatly for curvature of curved surface, each axle movement velocity generation acute variation of five-axis machine tool, and inertial force is larger on lathe impact, and this has proposed very high requirement to five-axis machine tool at the dynamics under high acceleration.For obtaining good height, accelerate five-axis machine tool dynamic property and processing characteristics, people have done large quantity research, mainly contain following aspect: Dynamic Characteristic of Machine Tool Structure optimization, Path fairness and speed of feed planning, the optimization of servo-control system acceleration-deceleration, servoly enter system optimization.Dynamic Characteristic of Machine Tool Structure optimization is mainly to improve lathe static rigidity and dynamic natural frequency, by changing lathe partial structurtes, realizes; It is mainly from complex parts character of surface to be processed, processing technology and machined parameters to be optimized that cutter track gauge is drawn the planning with speed of feed; And servo-control system and servo-drive system are to be mainly optimized from lathe responding ability.These work above, all do not contact directly machine tool structure Dynamics Optimization and processing work.When we need to produce certain complex parts in enormous quantities, can be according to the processing characteristics of part, as accessory size specification, part curvature of curved surface feature, analyze the dynamics that part adds man-hour, research and development special purpose machine tool, for the kinematic axis of lathe acceleration maximum configures minimum architecture quality, realize whole inertial force minimum, reach the global optimization of machine tool structure configuration.Rearmounted information recording all necessary informations of digital control processing campaign: the process sequence that part is processed, movement locus and orientation, technological parameter (the speed of mainshaft, speed of feed), by these parameters, can calculate each axle acceleration, and then realize the structure optimization configuration with overall inertial force minimum.It is example that this typical complex curved surface part of engine integral wheel is take in the present invention, utilizing Numerical Control Programming Software to treat Machining Free-Form Surfaces programmes, according to five-axis machine tool structure and numerical control system controller, generate rearmounted information, based on rearmounted information, five-axis machine tool is carried out to structure optimization configuration.

Summary of the invention

1, object: the object of this invention is to provide a kind of special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information.First utilize dedicated numerical control programming software to obtain the rearmounted information of complex free curved surface to be processed, each axis acceleration information while calculating Free-Form Surface Machining based on rearmounted information, comprise maximum acceleration value, acceleration profile and weighting acceleration, then according to each axle inertial force size to three translation shaft on five-axis machine tool the planning and configuration again of the order in machine tool motion chain, reduce the whole inertial force of lathe, improve Machine Tool Dynamics performance.

2, technical scheme:

A special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information, its feature comprises following step:

Step 1: each technical parameter according to be processed carries out free form surface numerical control programming, generates rearmounted information according to the first fixed structure parameter of five-axis machine tool and numerical control system controller.When selecting programming software, can select the softwares such as UG, PRO/E, CATIA, MAX-5, MAX-AB, Hypermill.

Step 2: utilize C language to extract lathe X, Y in rearmounted information, Z displacement and A, C Shaft angle and speed of feed.

1. displacement information and the speed of feed information except comprising lathe five coordinate axis in G code file, also comprises part model information, tool-information, lathe information at zero point, machining precision information, rotary speed information etc.Therefore be not, that each section of G code all can comprise displacement information.In the present invention, we claim that the program segment that comprises machine spindle displacement information or speed of feed information is effective procedure section.By several, the character string by space-separated forms a program segment, and each character string is comprised of letter and numerical value.The present invention regards letter as the address of the information such as displacement, speed of feed, cutter, and letter numerical value is below regarded the concrete numerical value of displacement, speed of feed, tool-information etc. information as, and information is by representing the letter of address and representing that the numeral of numerical value forms.Reading after rearmounted information by row, the information reading is decomposed by space, according to the validity of second character string determining program section of decomposing.

2. set up rearmounted information structure variable, this structure variable comprises the variable members such as each axle absolute displacement amount of five-axis machine tool, speed of feed.Utilize C language strtok function, according to G code interpreter principle, G code is carried out to control word decomposition, the information category obtaining according to the letter judgement in the information after decomposing, then deposits gained information in the structure variable member who believes in.Because each axial translation information and speed of feed information are not all to change in a program segment, may only have that in X, Y, Z, A, C axial translation, speed of feed F, one or several change, therefore often judge after an effective procedure section, need to set up a new structure variable, and previous structure variable information is assigned to new structure variable.For new structure variable member's value, only need to change the value of the effective information existing in current effective procedure section.

3. each axial translation information and the speed of feed information that in each process segment storage, enter in structure variable are write respectively to TXT file.

Step 3: utilize the information of extracting in step 2 to calculate each axle speed, acceleration in Free-Form Surface Machining process, obtain acceleration maximal value and acceleration profile, each cutter location accekeration is stored in each corresponding structure variable.

1. according to five-axis machine tool multi-coordinate interpolator principle, can obtain equivalent interpolation length between each cutter location and be

$L=\sqrt{{\mathrm{\ΔX}}^2+\mathrm{\Δ}{Y}^2+\mathrm{\Δ}{Z}^2+{\left(k_a\mathrm{\ΔA}\right)}^2+{\left(k_b\mathrm{\ΔB}\right)}^2+{\left(k_c\mathrm{\ΔC}\right)}^2}$

2. calculate working time, speed, acceleration and the acceleration maximal value of each axle between cutter location, and the temporal information calculating in each process segment and acceleration information are write respectively to TXT file.

$T=\frac{L}{V_{\mathrm{slop}}}$

$\left\{\begin{array}{c}{V}_{\mathrm{xi}}=\frac{x_{i+1}-x_i}{T_i}\\ V_{\mathrm{yi}}=\frac{y_{i+1}-y_i}{T_i}\\ V_{\mathrm{zi}}=\frac{z_{i+1}-z_i}{T_i}\end{array}\right.$

$\left\{\begin{array}{c}{a}_{\mathrm{xi}}=\frac{v_{x,i+1}-v_{x,i}}{T_i}\\ a_{\mathrm{yi}}=\frac{v_{y,i+1}-v_{y,i}}{T_i}\\ a_{\mathrm{zi}}=\frac{v_{z,i+1}-v_{z,i}}{T_i}\end{array}\right.$

$\left\{\begin{array}{c}{a}_{x\max }=\max \left(\right|a_{\mathrm{xi}}\left|\right)\\ a_{y\max }=\max \left(\right|a_{\mathrm{yi}}\left|\right)\\ a_{z\max }=\max \left(\right|a_{\mathrm{zi}}\left|\right)\end{array}\right.$

3. add up acceleration profile

$\left\{\begin{array}{c}F\left(a_x\right)=n_x/N\\ F\left(a_y\right)=n_y/N\\ F\left(a_z\right)=n_z/N\end{array}\right.$

Above-mentioned various symbol description is as follows:

Δ X, Δ Y, Δ Z, Δ A, Δ B, Δ C are respectively the displacement of X, Y between adjacent cutter location, Z, A, B, C axle, k _a, k _b, k _cfor speeds match coefficient, by lathe parameter, set, during calculating, angular displacement unit is directly converted to mm by spending;

L is equivalent composition length;

V _slopfor lathe actual motion speed after reduction of speed is processed;

X _i, y _i, z _ibe i cutter location displacement;

V _xi, v _yi, v _zibe i cutter location three translation shaft speed;

A _xi, a _yi, a _zibe i cutter location three translation shaft acceleration;

A _xmax, a _ymax, a _zmaxbe three translation shaft peak accelerations;

N _xfor X-axis acceleration absolute value is greater than a _xthe number of point;

N _yfor Y-axis acceleration absolute value is greater than a _ythe number of point;

N _zfor Z axis acceleration absolute value is greater than a _zthe number of point;

N is the total number of cutter location;

F(a _x) for X-axis acceleration absolute value, be greater than a _xthe ratio of point;

F(a _y) for X-axis acceleration absolute value, be greater than a _ythe ratio of point;

F(a _z) for X-axis acceleration absolute value, be greater than a _zthe ratio of point;

Step 4: utilize ADAMS Kinematics Simulation function, the time obtaining in step 2 and step the three, displacement, speed of feed TXT file are imported to ADAMS by CUBSPL function and carry out Kinematics Simulation, by figure output acceleration maximal value and high acceleration value, distribute intuitively.When output acceleration profile, for understanding clearly acceleration, there is position, the present invention first exports the Path planar figure in shielding rotational displacement situation, exports on this basis acceleration with the distribution of lathe axial translation value.Now, horizontal ordinate should be offset variable rather than time variable.

Step 5: each axle peak acceleration has represented the extreme case occurring in lathe operational process, but lathe is shorter in the running status time of peak acceleration.Therefore,, when the angle of our slave bed ensemble running status is optimized configuration to machine tool structure, the acceleration profile in lathe operational process need to be taken into account.High acceleration value is larger on the impact of lathe running status, and low acceleration is less on the impact of lathe running status, and the size of each accekeration proportion also has influence on lathe running status simultaneously.Therefore the present invention is usingd the accekeration of each cutter location and the inverse of cutter location sum as the weight factor of each cutter location acceleration in whole process, calculates weighting acceleration.

Weighted value computing formula is as follows:

$\left\{\begin{array}{c}{a}_x^q=\sqrt{\frac{\underset{i}{\overset{N}{\mathrm{\Σ}}}{\left(a_{x,i}\right)}^2}{N}}\\ a_y^q=\sqrt{\frac{\underset{i}{\overset{N}{\mathrm{\Σ}}}{\left(a_{y,i}\right)}^2}{N}}\\ a_z^q=\sqrt{\frac{\underset{i}{\overset{N}{\mathrm{\Σ}}}{\left(a_{z,i}\right)}^2}{N}}\end{array}\right.$

Wherein, formula symbol description is as follows:

be respectively X, Y, Z axis weighting acceleration;

Step 6: calculate respectively each axle inertial force size according to weighting acceleration and peak acceleration, analyze the rationality of each axle configuration of former lathe, magnitude relationship according to inertial force is optimized configuration to machine tool structure again, make the minimum axle of primary inertia force away from machine tool motion chain end, and primary inertia force greatest axis is in kinematic chain least significant end, near workpiece.

1. analyze optimize five-axis machine tool configuration, according to each linear axes series sequence, calculate the equivalent moving mass of each linear axes.

2. according to each axle equivalence moving mass and peak acceleration, calculate each axle maximum inertia force.

Maximum inertia force computing formula is as follows:

$\left\{\begin{array}{c}{F}_{x\max }=M_x{a}_{x\max }\\ F_{y\max }=M_y{a}_{y\max }\\ F_{z\max }=M_z{a}_{z\max }\end{array}\right.$

Wherein, formula symbol description is as follows:

M _x, M _y, M _zfor X, Y, Z axis, do not consider rotation axis and affect the equivalent moving mass in situation;

F _xmax, F _ymax, F _zmaxfor X, Y, Z axis maximum inertia force;

3. according to each axle equivalence moving mass and each axle weighting inertial force of weighting acceleration calculation.

Maximum inertia force computing formula is as follows:

$\left\{\begin{array}{c}{F}_x^q=M_x{a}_x^q\\ F_y^q=M_y{a}_y^q\\ F_z^q=M_z{a}_z^q\end{array}\right.$

Wherein, formula symbol description is as follows:

be respectively X, Y, Z axis weighting inertial force;

4. respectively to maximum inertia force F _xmax, F _ymax, F _zmaxwith weighting inertial force

sort, and compare the relative size relation of maximal value and minimum value, judge the rationality of former lathe configuration.

5. maximum inertia force or weighting inertial force are differed to the order exchange in machine tool motion chain of maximum diaxon, according to the order after changing, lathe one-piece construction is configured to optimization.

Wherein, the method for the rearmounted information of concrete extraction described in step 2 is:

1. set up structure variable, initialize.

2. read G code information, 3. the validity of discriminant information, if effectively, arrive step; If invalid, continue step 2..

3. judge the classification of effective information, gained numerical information category is stored in corresponding structure variable member.

4. set up new structure variable, by a upper structure variable information assignment, give new structure variable, if rearmounted information does not finish, arrive step 2.; Otherwise delete new structure variable.

5. the displacement information in structure variable and speed of feed information are write respectively to TXT file, EOP (end of program).Wherein, the circular of the axle acceleration of each described in step 3 is:

1) according to gang tool multi-coordinate table interpolator principle, calculate equivalent interpolation length between each cutter location.

2) according to the equivalent process time between equivalent each cutter location of interpolation length computation.

3) utilize method of difference to calculate each axle speed and acceleration.

Wherein, the concrete methods of realizing of the ADAMS Kinematics Simulation described in step 4 is:

1) in ADAMS, same position is set up three identical moving mass, sets up respectively kinematic pair on each moving mass, utilizes CUBSPL function to apply displacement information and the temporal information of three translation shaft.

2) when simulation result is exported, first export the movement locus of lathe in shielding rotation axis displacement situation, then export on this basis each axle acceleration, at this, slogan banner axle is not time but offset axis.

Wherein, the circular of the calculating weighting acceleration described in step 5 is:

In read step three, each acceleration file of record, asks quadratic sum by the X, Y, Z axis acceleration information in each process segment respectively, and adds up cutter location sum, calculates X, Y, Z axis acceleration arithmetic square root.

3, advantage and effect: the present invention has the following advantages:

1) special machine tool structure design is associated with piece surface characteristic, can makes full use of the advantage that 5-axis movement is learned, processing inertial force, driving force and power consumption are less.

2) by inertial force optimization corresponding to peak acceleration, considered the worst situation occurring in five-axis machine tool operational process, by inertial force optimization corresponding to weighting acceleration, consider the whole process of five-axis machine tool, can comprehensively improve the dynamic performance of lathe.

Accompanying drawing explanation

A kind of special purpose machine tool one-piece construction method for optimizing configuration process flow diagram based on rearmounted information of Fig. 1

The rearmounted information extraction process flow diagram of Fig. 2

Fig. 3-a is that each axle acceleration of integral wheel point machining tool is with position distribution graph of a relation

In figure, horizontal ordinate is Y-axis displacement, and ordinate is Z axis displacement and X, Y, Z axis acceleration;

Fig. 3-b is that each axle acceleration of Flow Passage of Integral Impeller finishing machine is with position distribution graph of a relation

In figure, horizontal ordinate is Y-axis displacement, and ordinate is X-axis displacement and X, Y, Z axis acceleration

Fig. 3-c is that each axle acceleration of integral wheel fillet finishing machine is with position distribution graph of a relation

In figure, horizontal ordinate is X-axis displacement, and ordinate is Y-axis displacement and X, Y, Z axis acceleration.

Fig. 4 is former machine tool structure model schematic diagram

ZYXA ' B ' type machine tool structure model schematic diagram after Fig. 5 optimizes

Embodiment

The present invention is a kind of special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information.With reference to Fig. 1 method flow diagram, it is structure configuration optimization object that the two cradle lathes of HERMELC40-AC axle are take in the present invention, and selecting integral wheel cost part is example.First utilize dedicated integral impeller Numerical Control Programming Software to obtain integral wheel processing Path, according to five-axis machine tool structural parameters and corresponding controller S840D, generate rearmounted information, calculate integral wheel and add each axis acceleration information in man-hour, then according to each axle inertial force size to three translation shaft the planning and configuration again of the order in machine tool motion chain, reduce the whole inertial force of lathe, improve Machine Tool Dynamics performance.

A kind of special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information of the present invention, it comprises following concrete steps:

Step 1: complete integral wheel numerical control programming and generate rearmounted information according to the parameter in table 1, table 2, table 3, impeller diameter 205mm, minimum diameter 150mm, impeller height 19mm, maximum blade thickness 0.78mm, the blade number of blade 37.

The general rose cutter blade point of table 1 diameter phi 5 processing and milling parameter

The general rose cutter runner of table 2 diameter phi 5 finishing Milling Parameters

The general rose cutter fillet of table 3 diameter phi 3 finishing Milling Parameters

Step 2: with reference to Fig. 2 method flow diagram, read the G code in rearmounted file, each numerical control program section is comprised of several words, the set that each word is comprised of the letter and number that represents address, decomposes control word according to letter.It is below program segment example.

24L X2.6796 Y-8.847 Z103.6799 A85.9825 C82.8513 F1000

The Framing Characters of L judgement effective procedure section in example, X, Y, Z, A, C, is respectively each axial translation of lathe and speed of feed address, and letter numeral is below that each axial translation value of lathe and speed of feed are big or small.

Step 3: each axle acceleration of each cutter location calculates

$L=\sqrt{{\mathrm{\ΔX}}^2+\mathrm{\Δ}{Y}^2+\mathrm{\Δ}{Z}^2+{\left(k_a\mathrm{\ΔA}\right)}^2+{\left(k_b\mathrm{\ΔB}\right)}^2+{\left(k_c\mathrm{\ΔC}\right)}^2}$

The AC axle cradle-type lathe of optimization of the present invention is quadrature lathe, therefore chooses k _a=1, k _b=0, k _c=1

$T=\frac{L}{V_{\mathrm{slop}}}$

The present invention actual feed V of reduction of speed after processing that learn from else's experience _slopfor program setting speed of feed V _prog.

$\left\{\begin{array}{c}{V}_{\mathrm{xi}}=\frac{x_{i+1}-x_i}{T_i}\\ V_{\mathrm{yi}}=\frac{y_{i+1}-y_i}{T_i}\\ V_{\mathrm{zi}}=\frac{z_{i+1}-z_i}{T_i}\end{array}\right.$

$\left\{\begin{array}{c}{a}_{\mathrm{xi}}=\frac{v_{x,i+1}-v_{x,i}}{T_i}\\ a_{\mathrm{yi}}=\frac{v_{y,i+1}-v_{y,i}}{T_i}\\ a_{\mathrm{zi}}=\frac{v_{z,i+1}-v_{z,i}}{T_i}\end{array}\right.$

Step 4: peak acceleration and acceleration profile in machine tooling operational process

Each characteristic acceleration maximum value calculation formula:

$\left\{\begin{array}{c}{a}_{x\max }=\max \left(\right|a_{\mathrm{xi}}\left|\right)\\ a_{y\max }=\max \left(\right|a_{\mathrm{yi}}\left|\right)\\ a_{z\max }=\max \left(\right|a_{\mathrm{zi}}\left|\right)\end{array}\right.$

Each characteristic acceleration maximal value is in Table 4

Each characteristic acceleration maximal value of table 4

Acceleration profile statistical formula is as follows:

$\left\{\begin{array}{c}F\left(a_x\right)=n_x/N\\ F\left(a_y\right)=n_y/N\\ F\left(a_z\right)=n_z/N\end{array}\right.$

Each characteristic acceleration distributes in Table 5

Each characteristic acceleration of table 5 distributes

Step 5: in order to understand clearly the distribution of acceleration, and the magnitude relationship between three translation shaft is had to individual getting information about, at same position, place three rigid bodies, apply respectively the motion of three directions, these three motions each axial translation file that rearmounted information obtains of serving as reasons.Integral wheel point processing part, take Y-axis displacement as horizontal ordinate, with Z axis displacement and X, Y, Z axis acceleration ordinate; Flow Passage of Integral Impeller finishing and impeller fillet finishing part, with Y-axis displacement horizontal ordinate, take X-axis displacement and X, Y, Z axis acceleration is ordinate.In machine tooling each axle acceleration with the variation of Working position as shown in Fig. 3-a, Fig. 3-b and Fig. 3-c.

The present invention is with lower than the peaked 20% cutter location Wei Di acceleration district of acceleration, from table 5 and Fig. 3-a, Fig. 3-b and Fig. 3-c, in each feature machining process, the cutter spacing ratio of counting in low acceleration district accounts for more than 96%, and in whole process, each axle most of the time of lathe is in low acceleration operation state.Therefore, high acceleration value has represented the extreme case that lathe operational process occurs, lathe is shorter working time at high-g condition.From the angle of whole process, consider, each cutter location accekeration need to be taken into account by the factor of influence in lathe whole service process, below introducing weighting acceleration concept.

Weighting acceleration formula:

$\left\{\begin{array}{c}{a}_x^q=\sqrt{\frac{\underset{i}{\overset{N}{\mathrm{\Σ}}}{\left(a_{x,i}\right)}^2}{N}}\\ a_y^q=\sqrt{\frac{\underset{i}{\overset{N}{\mathrm{\Σ}}}{\left(a_{y,i}\right)}^2}{N}}\\ a_z^q=\sqrt{\frac{\underset{i}{\overset{N}{\mathrm{\Σ}}}{\left(a_{z,i}\right)}^2}{N}}\end{array}\right.$

Each feature machining acceleration maximal value, acceleration weighted value are as table 4.

Table 4 integral wheel is processed rearmounted information comprehensive analysis

Step 6: HERMLEC40 five-axis machine tool model sketch is as Fig. 4.

According to HERMLEC40 lathe configuration, in kinematic chain from workpiece farthest, y-axis shift moves with lathe X, Z axis when moving Y-axis together, therefore has: M _y=m _x+ m _y+ m _z.

In like manner have: M _x=m _x+ m _z, M _z=m _z.

Each several part mass parameter is: m _x=1100kg, m _y=500kg, m _z=300kg

According to machine tool structure, each axle maximum inertia force computing formula:

$\left\{\begin{array}{c}{F}_{x\max }=M_x{a}_{x\max }\\ F_{y\max }=M_y{a}_{y\max }\\ F_{z\max }=M_z{a}_{z\max }\end{array}\right.$

Each axle weighting inertial force computing formula:

$\left\{\begin{array}{c}{F}_x^q=M_x{a}_x^q\\ F_y^q=M_y{a}_y^q\\ F_z^q=M_z{a}_z^q\end{array}\right.$

Each axle inertial force result of calculation is as table 8

Table 8 is optimized front maximum inertia force and weighting inertial force

	Moving-member quality	Peak acceleration	Weighting acceleration	Maximum inertia force	Weighting inertial force
						X-axis	1400kg	0.267g	0.0103g	1335N	51.5N
Y-axis	1900kg	0.173g	0.00835g	1903N	91.85N
						Z axis	300kg	0.0572g	0.00522g	171.6N	15.66N

Maximum inertia force has represented the worst running status of lathe, and weighting inertial force has represented the running status of lathe in whole process.As shown in Table 8, F _ymax/ F _zmaxbe 11,

be 6, and F _ymax/ F _xmaxbe 1.4,

be 1.7, Z axis acceleration is minimum, and moving-member quality is minimum, and at kinematic chain least significant end, inertial force is much smaller than X, Y-axis with but.Obviously very unreasonable, Z axis should be configured in to the distal-most end of three kinematic chains, changing existing YXZA ' C ' type lathe is ZXYA ' B ' type horizontal machine tool, as Fig. 5.After lathe optimization, inertial force result is as shown in table 9.

Table 8 is optimized rear maximum inertia force and weighting inertial force

	Moving-member quality	Peak acceleration	Weighting acceleration	Maximum inertia force	Weighting inertial force
						X-axis	500kg	0.267g	0.0103g	1335N	52N
Y-axis	143kg	0.173g	0.00835g	247N	12N
						Z axis	635kg	0.0572g	0.00522g	363N	33N

Before optimization, lathe one-piece construction maximum inertia force:

$F_{\max }=\sqrt{F_x^2+F_y^2+F_z^2}=2331N$

Before optimization, lathe one-piece construction weighting inertial force:

$F_{\mathrm{weight}}=\sqrt{F_x^2+F_y^2+F_z^2}=107N$

After optimization, lathe one-piece construction maximum inertia force:

$F_{\max }^{\mathrm{opt}}=\sqrt{F_x^2+F_y^2+F_z^2}=1405N$

After optimization, lathe one-piece construction weighting inertial force:

$F_{\mathrm{weight}}^{\mathrm{opt}}=\sqrt{F_x^2+F_y^2+F_z^2}=63N$

After optimization, lathe one-piece construction maximum inertia force reduces 40%, lathe one-piece construction weighting inertial force 42%.

Claims (5)

1. the special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information, is characterized in that: it comprises the following steps:

Step 1: each technical parameter according to be processed carries out free form surface numerical control programming, according to the first fixed structure parameter of five-axis machine tool and numerical control system controller, generate rearmounted information, when selecting programming software, select any in UG, PRO/E, CATIA, MAX-5, MAX-AB, Hypermill software all can;

Step 2: utilize C language to extract lathe X, Y in rearmounted information, Z displacement and A, C Shaft angle and speed of feed;

1. displacement information and the speed of feed information except comprising lathe five coordinate axis in G code file, also comprise part model information, tool-information, lathe information at zero point, machining precision information and rotary speed information, therefore be not, that each section of G code all can comprise displacement information; The program segment of machine spindle displacement information or speed of feed information is made as effective procedure section, and program segment is comprised of the character string of a plurality of space-separated, and each character string is comprised of letter and numerical value; The address of letter being regarded as to displacement, speed of feed and tool-information, letter numerical value is below regarded the concrete numerical value of displacement, speed of feed and tool-information as, and information is by representing the letter of address and representing that the numeral of numerical value forms; Reading after rearmounted information by row, the information reading is decomposed by space, according to the validity of second character string determining program section of decomposing;

2. set up rearmounted information structure variable, this structure variable comprises each axle absolute displacement amount of five-axis machine tool, speed of feed variable member, utilize C language strtok function, according to G code interpreter principle, G code is carried out to control word decomposition, the information category obtaining according to the letter judgement in the information after decomposing, then deposits gained information in corresponding structure variable member; Because each axial translation information and speed of feed information are not all to change in a program segment, only have that in X, Y, Z, A, C axial translation, speed of feed F, one or several change, therefore often judge after an effective procedure section, need to set up a new structure variable, and previous structure variable information is assigned to new structure variable; For new structure variable member's value, only need to change the value of the effective information existing in current effective procedure section;

3. each axial translation information and the speed of feed information that in each process segment storage, enter in structure variable are write respectively to TXT file;

Step 3: utilize the information of extracting in step 2 to calculate each axle speed, acceleration in Free-Form Surface Machining process, obtain acceleration maximal value and acceleration profile, each cutter location accekeration is stored in each corresponding structure variable;

1. according to five-axis machine tool multi-coordinate interpolator principle, obtain equivalent interpolation length between each cutter location and be

$L=\sqrt{\mathrm{\Δ}{X}^2+\mathrm{\Δ}{Y}^2+\mathrm{\Δ}{Z}^2+{\left(k_a\mathrm{\ΔA}\right)}^2+{\left(k_b\mathrm{\ΔB}\right)}^2+{\left(k_c\mathrm{\ΔC}\right)}^2}$

2. calculate working time, speed, acceleration and the acceleration maximal value of each axle between cutter location, and the temporal information calculating in each process segment and acceleration information are write respectively to TXT file;

$T=\frac{L}{V_{\mathrm{slop}}}$

$\left\{\begin{array}{c}{V}_{\mathrm{xi}}=\frac{x_{i+1}-x_i}{T_i}\\ V_{\mathrm{yi}}=\frac{y_{i+1}-y_i}{T_i}\\ V_{\mathrm{zi}}=\frac{z_{i+1}-z_i}{T_i}\end{array}\right.$

$\left\{\begin{array}{c}{a}_{\mathrm{xi}}=\frac{v_{x,i+1}-v_{x,i}}{T_i}\\ a_{\mathrm{yi}}=\frac{v_{y,i+1}-v_{y,i}}{T_i}\\ a_{\mathrm{zi}}=\frac{v_{z,i+1}-v_{z,i}}{T_i}\end{array}\right.$

$\left\{\begin{array}{c}{a}_{x\max }=\max \left(\right|a_{\mathrm{xi}}\left|\right)\\ a_{y\max }=\max \left(\right|a_{\mathrm{yi}}\left|\right)\\ a_{z\max =}\max \left(\right|a_{\mathrm{zi}}\left|\right)\end{array}\right.$

3. add up acceleration profile

$\left\{\begin{array}{c}F\left(a_x\right)=n_x/N\\ F\left(a_y\right)=n_y/N\\ F\left(a_z\right)=n_z/N\end{array}\right.$

Above-mentioned various symbol description is as follows:

Δ X, Δ Y, Δ Z, Δ A, Δ B, Δ C are respectively the displacement of X, Y between adjacent cutter location, Z, A, B, C axle, k _a, k _b, k _cfor speeds match coefficient, by lathe parameter, set, during calculating, angular displacement unit is directly converted to mm by spending;

L is equivalent composition length;

V _slopfor lathe actual motion speed after reduction of speed is processed;

X _i, _yi, z _ibe i cutter location displacement;

V _xi, v _yi, v _zibe i cutter location three translation shaft speed;

A _xi, a _yi, a _zibe i cutter location three translation shaft acceleration;

A _xmax, a _ymax, a _zmaxbe three translation shaft peak accelerations;

N _xfor X-axis acceleration absolute value is greater than a _xthe number of point;

N _yfor Y-axis acceleration absolute value is greater than a _ythe number of point;

N _zfor Z axis acceleration absolute value is greater than a _zthe number of point;

N is the total number of cutter location;

F(a _x) for X-axis acceleration absolute value, be greater than a _xthe ratio of point;

F(a _y) for X-axis acceleration absolute value, be greater than a _ythe ratio of point;

F(a _z) for X-axis acceleration absolute value, be greater than a _zthe ratio of point;

Step 4: utilize ADAMS Kinematics Simulation function, the time obtaining in step 2 and step the three, displacement, speed of feed TXT file are imported to ADAMS by CUBSPL function and carry out Kinematics Simulation, by figure output acceleration maximal value and high acceleration value, distribute intuitively; When output acceleration profile, for understanding clearly acceleration, occur position, the Path planar figure in first output shielding rotational displacement situation, exports acceleration on this basis with the distribution of lathe axial translation value, now, horizontal ordinate is offset variable rather than time variable;

Step 5: each axle peak acceleration has represented the extreme case occurring in lathe operational process, but lathe is shorter in the running status time of peak acceleration, therefore, when the angle of our slave bed ensemble running status is optimized configuration to machine tool structure, the acceleration profile in lathe operational process need to be taken into account; High acceleration value is large on the impact of lathe running status, and low acceleration is little on the impact of lathe running status, the size of each accekeration proportion also has influence on lathe running status simultaneously, therefore using the accekeration of each cutter location and the inverse of cutter location sum as the weight factor of each cutter location acceleration in whole process, calculate weighting acceleration;

Weighted value computing formula is as follows:

$\left\{\begin{array}{c}{a}_x^q=\sqrt{\frac{\underset{i}{\overset{N}{\mathrm{\Σ}}}{\left(a_{x,i}\right)}^2}{N}}\\ a_y^q=\sqrt{\frac{\underset{i}{\overset{N}{\mathrm{\Σ}}}{(a_y,i)}^2}{N}}\\ a_z^q=\sqrt{\frac{\underset{i}{\overset{N}{\mathrm{\Σ}}}{\left(a_{z,i}\right)}^2}{N}}\end{array}\right.$

Wherein, formula symbol description is as follows:

be respectively X, Y, Z axis weighting acceleration;

Step 6: calculate respectively each axle inertial force size according to weighting acceleration and peak acceleration, analyze the rationality of each axle configuration of former lathe, magnitude relationship according to inertial force is optimized configuration to machine tool structure again, make the minimum axle of primary inertia force away from machine tool motion chain end, and primary inertia force greatest axis is in kinematic chain least significant end, near workpiece;

1. analyze optimize five-axis machine tool configuration, according to each linear axes series sequence, calculate the equivalent moving mass of each linear axes;

2. according to each axle equivalence moving mass and peak acceleration, calculate each axle maximum inertia force;

Maximum inertia force computing formula is as follows:

$\left\{\begin{array}{c}{F}_{x\max }=M_x{a}_{x\max }\\ F_{y\max }=M_y{a}_{y\max }\\ F_{z\max =}{M}_z{a}_{z\max }\end{array}\right.$

Wherein, formula symbol description is as follows:

M _x, M _y, M _zfor X, Y, Z axis, do not consider rotation axis and affect the equivalent moving mass in situation;

F _xmax, F _ymax, F _zmaxfor X, Y, Z axis maximum inertia force;

3. according to each axle equivalence moving mass and each axle weighting inertial force of weighting acceleration calculation;

Maximum inertia force computing formula is as follows:

$\left\{\begin{array}{c}{F_x}^q=M_x{a}_x^q\\ {F_y}^q=M_y{a}_y^q\\ {F_z}^q=M_z{a}_z^q\end{array}\right.$

Wherein, formula symbol description is as follows:

F _x ^q, F _x ^q, F _z ^qbe respectively X, Y, Z axis weighting inertial force;

4. respectively to maximum inertia force F _xmax, F _ymax, F _zmaxwith weighting inertial force F _x ^q, F _x ^q, F _z ^qsort, and compare the relative size relation of maximal value and minimum value, judge the rationality of former lathe configuration;

5. maximum inertia force or weighting inertial force are differed to the order exchange in machine tool motion chain of maximum diaxon, according to the order after changing, lathe one-piece construction is configured to optimization.

2. a kind of special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information according to claim 1, is characterized in that: the method for the rearmounted information of concrete extraction described in step 2 is:

1. set up structure variable, initialize;

2. read G code information, 3. the validity of discriminant information, if effectively, arrive step; If invalid, continue step 2.;

3. judge the classification of effective information, gained numerical information category is stored in corresponding structure variable member;

4. set up new structure variable, by a upper structure variable information assignment, give new structure variable, if rearmounted information does not finish, arrive step 2.; Otherwise delete new structure variable;

5. the displacement information in structure variable and speed of feed information are write respectively to TXT file, EOP (end of program).

3. a kind of special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information according to claim 1, is characterized in that: the circular of each axle acceleration described in step 3 is:

1) according to gang tool multi-coordinate table interpolator principle, calculate equivalent interpolation length between each cutter location;

2) according to the equivalent process time between equivalent each cutter location of interpolation length computation;

3) utilize method of difference to calculate each axle speed and acceleration.

4. a kind of special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information according to claim 1, is characterized in that: the concrete methods of realizing of the ADAMS Kinematics Simulation described in step 4 is:

1) in ADAMS, same position is set up three identical moving mass, sets up respectively kinematic pair on each moving mass, utilizes CUBSPL function to apply displacement information and the temporal information of three translation shaft;

2) when simulation result is exported, first export the movement locus of lathe in shielding rotation axis displacement situation, then export on this basis each axle acceleration, at this, slogan banner axle is not time but offset axis.

5. a kind of special purpose machine tool one-piece construction method for optimizing configuration based on rearmounted information according to claim 1, is characterized in that: the circular of the calculating weighting acceleration described in step 5 is:

In read step three, each acceleration file of record, asks quadratic sum by the X, Y, Z axis acceleration information in each process segment respectively, and adds up cutter location sum, calculates X, Y, Z axis acceleration arithmetic square root.

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