CN103942041A - Design method of NC code interpreter in numeric control simulation system - Google Patents

Abstract

Provided is a design method of an NC code interpreter in a numeric control simulation system. Feature classification is carried out on NC procedure codes, a general rule database is constructed, in the grammatical analysis process, a standard numeric control code rule is described formally through a regular expression, at the same time, the grammatical analysis is carried out on the NC codes based on the recursive-descent parsing method from top to bottom, for default instruction words, corresponding preparatory function procedure words are deduced from non-default instruction words automatically and upwards, the default instruction words are automatically complemented through the preparatory function procedure words according to the rule database, and the flexibility and the grammatical analysis efficiency of the NC code interpreter are improved greatly.

Description

The method for designing of NC code interpretative device in a kind of Numerical Control Machining Simulation

Technical field

The present invention relates to the method for designing of NC code interpreter in a kind of NC lathe machining simulation system, specifically refer to the method for designing of code interpretative device in a kind of Numerical Control Machining Simulation.

Background technology

Numerical control machining simulation system is the mapping in computing machine as actual process, and its process also should be controlled by numerical control program.And NC code interpretative device becomes motion command as a nucleus module in Numerical Control Machining Simulation by NC code interpreter, drive cutter to carry out the processing of part.

The NC code interpretative device technical issues that need to address mainly contain lexical analysis, grammatical analysis, the processing instruction transformation of NC code.Numerical control program explains that the operation efficiency of decoding directly affects effect and the precision of numerical control machining simulation system.

With regard to numerical control NC, explain decoding technique, research both at home and abroad obtains a series of achievement.Sha Zhihua and 5 degeneration-resistant propositions utilize special-purpose LEX instrument automatically to generate lexical analyzer, and adopt regular formula to describe morphological rule, simple in rule, are applicable to the lexical analysis of simple NC code.Trip Hua Yun, adopting on the basis of special-purpose LEX instrument, utilizes regular expression to describe numerical control code and carries out grammatical feature description.This kind of method adopts suitable optimization method, generates high efficiency lexical scan device.The people such as LEE WB propose a kind of more efficient special-purpose morphology instrument ANTLR, set morphology description rule, and rule is imported in ANTLR and just can generate lexical analyzer.The people such as Li Shanfeng and GUO DE-GU analyze the relation between processing instruction and shape, and processing instruction is classified.This kind of method adopts top-down algorithm to carry out grammatical analysis, adopts eight yuan of formula structure record syntax analysis results simultaneously, makes grammatical analysis flow process simple.The people such as Ji Hua and Liu Yadong are described grammer by setting address word table, and G code is divided into groups, and utilize function pointer to realize the decomposition of address word simultaneously, and lexical analysis is simple, clear.Make system constructing become simple.The people such as flood great waves have set up grammar mistake testing mechanism according to the different grouping of G code and M code.The method is carried out mode grouping, by the code grouping of action attributes of the same race, improve grammatical analysis efficiency, but algorithm is complicated.

Summary of the invention

The object of the present invention is to provide the method for designing of NC code interpretative device in a kind of Numerical Control Machining Simulation, NC code interpretative device high efficiency in realization and raising Numerical Control Machining Simulation.Technical scheme provided by the invention is as follows:

In Numerical Control Machining Simulation, NC code interpretative device execution step is as follows successively:

(1) lexical analysis, the instruction set based on tagsort, builds rule database, and according to rule database, adopts address word function table to solve address word resolution problem in lexical analysis, gets rid of thus the unallowable instruction digit in numerical control program.

(2) grammatical analysis, adopt regular expression to carry out formal description to standard numerical control code regulation, and adopt top-down recursive descent parsing method, with above-mentioned regular expression description rule, travel through whole numerical control program, the illegal program statement in rejected program.

(3) processing instruction transformation, numerical control program is through lexical analysis, grammatical analysis, in rule database, set up the index relative between numerical control program instruction address word and instruction address word function, read processing instruction, according to index relative, call corresponding function and process, parse cutter location file corresponding to instruction, for driving cutter to process.

Advantage of the present invention is as follows: the present invention proposes the method for designing of NC code interpretative device in a kind of Numerical Control Machining Simulation.NC program code is carried out to tagsort, and formation rule database, decomposes NC instruction based on address word function table and carries out lexical analysis simultaneously.Adopt regular expression to carry out formal description to standard numerical control code regulation, grammar rule is simple, simultaneously based on top-down recursive descent parsing method, grammatical analysis is carried out in instruction lexical analysis being obtained with above-mentioned grammar rule, for the default situation of program word, auto-complete program, improves dirigibility and the applicability of NC interpreter greatly.

Accompanying drawing explanation

The overall flowchart of Fig. 1 the present invention

Fig. 2 lexical analysis process flow diagram of the present invention

Fig. 3 grammatical analysis process flow diagram of the present invention

Fig. 4 the present invention supplements example code process flow diagram automatically

The whole code flow figure that automatically supplements of Fig. 5 the present invention

Embodiment

For realizing goal of the invention, make technical scheme and feature clearer, below in conjunction with drawings and the specific embodiments, the invention will be further described:

Accompanying drawing 1 is the whole flowchart of NC code interpretative device of the present invention.

Flow process comprises the lexical analysis of NC code, grammatical analysis, processing instruction transformation, and concrete steps are as follows:

Lexical analysis

The first step: according to the relation between processing instruction and machining shape, processing instruction is carried out to tagsort, comprise the function types such as single interpolation, specific interpolation, fixed cycles, free curve.As shown in the table:

Processing instruction tagsort table

Command function	Instruction feature	Instruction set
			Single interpolation	Procedure of processing is single	The interpolation such as straight line, circular arc
Specific interpolation	There is definite procedure of processing	Thread cylinder polar coordinate interpolation
			Fixed cycles	To fixed cell cyclic process	The instruction of various fixedly fabrication cycles
Free curve	Need machined parameters and circulation point	Free curve class interpolation instruction

According to sorted instruction, formation rule database is specified address word and rules of order in database, comprising:

One, rules of order

1, preparatory function word G (setting up the mode of motion of digital control system), rule is as follows:

Gnn?Xnnnn.nnn?Ynnnn.nnn(Rnnnn.nnn)

2, subsidiary function word M (the definition state of main shaft and the state of liquid coolant), rule is as follows:

Mnn

3, address word F, S etc. (specifying cutting speed of feed, main shaft gyration number etc.), rule is as follows:

Fnnnn、Snnnn。Wherein n span is 0～9.

Two, set up the common character list in digital control system, for the lexical analysis of NC code, character list is as follows:

Letter: A～Z;

Numeral: 0|1|2|3|4|5|6|7|8|9;

Symbol: .|+|-|; | %|:|; |

Three, set up address word function table, function table, for analyzing the address word reading, is its matching parameter and command function, and address word function table is as follows:

analyze_function_pointer_analyze?s[]=

{analyze_f，analyze_g，analyze_i，

analyze_j,analyze_K，analyze_m，

analyze_x,analyze_y,analyze_z，......}

Function in call list is address word matching parameter and command function, extracts machining information.

Second step: read in row of N C code, it is carried out to pretreatment operation, the garbage in the middle of removing (annotation and space).After pre-service, NC code is separated into the set of some program words.For example, for row of N C code N0001G00X200Y300, can be decomposed into " N0001 ", " G00 ", " X200 ", " Y200 " these four program words.

The 3rd step: for the program word decompositing, analyze first one by one each character, get rid of character mistake; Next is broken down into address word and numerical value, and in call address function of word table, corresponding function is done further processing to address word.For example, for " G00 " program word, the analyze_g function in call function table for its coupling fast positioning function, is specified X-axis and Y-axis parameter according to rules of order for it according to the numerical value decompositing simultaneously, and parameter value scope.

Grammatical analysis

Syntactic analyser is the core of program compiler, and its effect is whether the word sequence that judgement is provided by lexical analysis meets given grammar form.The NC code regulation of describing for EBNF (Backus normal form of expansion) is complicated, grammatical analysis efficiency is low, require the deficiency of the complete NC code of input, the present invention proposes to adopt regular expression to describe NC code grammar rule, simultaneously based on making downward analytic approach by oneself, the regular expression rule of take is carried out grammatical analysis as nonterminal symbol search rule, and automatically supplements default program word for incomplete numerical control program.Specific as follows:

The first step: adopt regular expression to carry out formal description to standard numerical control code regulation, set up NC code regular expression grammar rule, NC code regulation has following rule conventionally:

Program number rule, by a capital O and four program numbers that numeral forms, can generate following rule according to standard:

O\d{4}

Program segment sequence number rule, is comprised of capital N and 4 numerals, according to standard, generates following rule:

N\d{4}

Address word G and M etc.: by capitalization G or M and two numerals, formed, according to standard, generate following rule:

G d{2} and M d{2}

Address word F and S etc.: by capital F or S and two numerals, formed, according to standard, generate following rule:

F d{4} and S d{4}

Second step: according to top-down recursive descent parsing method, from the initial rule of regular expression, derive downwards by leftmost derivation mode, for each nonterminal symbol constructor program, call successively corresponding process downwards, complete the analysis of full line code, get rid of illegal program segment.The NC code reading has instruction word abridged situation, automatically supplements default program word.

For example:

N0001G01X30Z-50F100；

N0002X42；

At N0002 line program, according to semantic known above, default G01, Z-50, F100 supervisor word need automatically to be supplemented complete, specific as follows in automatically downward analytic process:

(1) while reading X42, from then on line code starts automatically upwards to derive, and finds nearest program word G01, by reading the rule of this program word in rule base, and based on regular expression, default program word G01, Z-50, F100 are described, be constructed as follows rule:

_G01_Z-50F100

(2) X42 is replaced X30 to add in default program word simultaneously, forms complete program, supplement the complete following program that obtains:

N0002_X42__+_G01_Z-50F100=

N0002G01X42Z-50F100：

Whole process as shown in Figure 4.

After NC numerical control code is supplementary complete, from initial rule, call subroutine is analyzed full line code successively.

Processing instruction transformation

Index relative between Database numerical control program instruction address word and instruction address word function, NC numerical control code is through grammatical analysis, and lexical analysis, obtains standard NC code.According to the row of N C code reading, the address word invoking performance function being gone out by address word function decomposition, analyze the address word number of every row NC program, species code of address word, address word data type, data type species code, number of parameters, parameter species code, supplemental characteristic species code etc. obtain the cutter location file information that driving arrangement is processed.

By speed of feed v (mm/min) and timeslice T (ms), calculate amount of feeding f (mm).

$f=\frac{v}{60\×1000}\×T---\left(1\right)$

By f and arc radius R, calculate central angle δ (radian) corresponding to tool feeding in the sheet T time.

$\mathrm{\δ}=2\arcsin \frac{f}{2R}---\left(2\right)$

According to the coordinate of circular arc starting point S and terminal E and arc radius R, calculate the central angle θ (radian) of circular arc.

$\mathrm{\θ}=2\arcsin =\frac{\sqrt{{(x_E-x_S)}^2+{(y_E-y_S)}^2}}{2R}---\left(3\right)$

The displacement of i step is calculated as follows:

$\left\{\begin{array}{c}\mathrm{\Δ}{x}_i=R[\cos (\mathrm{\α}+\mathrm{i\δ})-\cos (\mathrm{\α}+(i-1)\mathrm{\δ})]\\ \mathrm{\Δ}{y}_i=R[\sin (\mathrm{\α}+\mathrm{i\δ})-\sin (\mathrm{\α}+(i-1)\mathrm{\δ})]\end{array}\right.---\left(4\right)$

The initial angle that wherein α is circular arc, just can obtain the interior circular interpolation of each T in the displacement of change in coordinate axis direction by (4) formula.

Claims (2)

1. the object of the present invention is to provide the method for designing of NC code interpretative device in a kind of Numerical Control Machining Simulation, it is characterized in that: processing instruction is carried out to tagsort, build rule database, according to address word constructed fuction table, by address word binding rule storehouse, carry out lexical analysis; Adopt regular expression to carry out formal description to standard numerical control code regulation simultaneously, and adopt top-down recursive descent parsing method to carry out grammatical analysis, for there being the default situation of instruction word, automatic makeup charges whole numerical control code, greatly improves dirigibility and the programming efficiency of the grammatical analysis of NC interpreter.Comprise following several step:

Lexical analysis

The first step: processing instruction is carried out to tagsort, and formation rule database, based on address word in storehouse, constructs address word function table simultaneously;

Second step: read a line numerical control program, carry out pre-service, remove space and annotation, and program is resolved into program word;

The 3rd step: to the program word decompositing, reading character, gets rid of character mistake, is broken down into address word and numerical value, and calls corresponding address function of word in conjunction with the numerical value decompositing, is program word coupling holding function, with and parameter characteristic;

Grammatical analysis

The first step: set up regular expression grammar rule, as follows for conventional NC code regulation:

Program number rule: O \ d{4}; Program segment sequence number rule: N d{4};

The rule such as address word G and M: G \ d{2} and M d{2};

The rule such as address word F and S: F d{4} and S \ d{4};

Second step: according to top-down recursive descent parsing method, from the initial rule of regular expression, derive and carry out grammatical analysis downwards by leftmost derivation mode; For NC code, there is the default situation of instruction word, the rule of describing with regular expression, automatically supplement default program word, step specific as follows:

(1) while reading not default program word, from then on line code starts automatically upwards to derive, and according to rule base and regular expression, constructs default program word rule;

(2) not default program word rule is added in default program word rule, form complete program, after NC numerical control code is supplementary complete, from initial rule, call subroutine is analyzed full line code successively.

2. the method for designing of NC code interpretative device in a kind of Numerical Control Machining Simulation according to claim 1, is characterized in that; In described grammatical analysis second step, comprising:

In top-down method, calling regular expression describes numerical control program syntax rule and carries out in grammatical analysis, run into the program that has default procedures word, shape is as Nnnnn Xnnnn.nnn (other situation default procedures word processing processes are similar), automatic basis is semantic completion program above, specific as follows:

(1) in top-down method, according to not default program word Xnnnn.nnn, from Nnnnn line code start upwards to derive the successively program word Gnn of associated, definition according to Gnn in rule base, search corresponding with it parameter, and utilize regular expression to construct default program word form, shown in being constructed as follows:

_Gnn_Y|Znnnn.nnn(R|Fnnnn.nnn)；

(2) form complete program with not default program word Xnnnn.nnn, anabolic process is as follows:

Nnnnn_Xnnnn.nnn_(_)；+_Gnn_Y|Znnnn.nnn(R|Fnnnn.nnn)；＝Nnnnn?Gnn?Xnnnn.nnn?Y|Znnnn.nnn(R|Fnnnn.nnn)；

Whole automatically supplementary process as shown in Figure 5.

After full line code is supplementary complete, from the initial rule of regular expression, by leftmost derivation mode, derive downwards, for each nonterminal symbol constructor program, call successively corresponding process downwards, complete the grammatical analysis of full line code.