CN100514002C - Method for realizing numerical control rotating platform angular displacement forecast measurement using time gate displacement sensor - Google Patents

Abstract

This invention provides a sort of metrical method which realizes the forecast of the angular displacement of the numerical control rotating floor by the time-bar displacement sensing device. Add an intelligent interface unit between the time-bar and the numerical control system, the import of the intelligent interface unit is the absolute value of the angle which is measured by the time-bar; the export is the increment type impulse signal which can connects with the currency numerical control system. The intelligent interface unit progresses the forecast to the angular displacement figures in the unborn spell according to several discrete absolute value of the measured angle of the time-bar which is in the nonce and in the past. It corrects the predictive error figures which are in the former time slice according to the real measured angle figures which is in now. It realizes the predictive measure of the angular displacement of the numerical control rotating floor. This invention applies to the displacement sensing device with the timing sampling that the time-bar is used to be the deputation, and it applies to the position feedback of the whole closed loop which is from the function unit of the numerical control division likes the numerical control rotating floor, and so on.

Description

Displacement transducer is realized the method that numerical control rotating platform angular displacement prediction is measured when utilizing

Technical field

The present invention relates to a kind of displacement transducer prediction new measurement method, can with the time grid be that the timing sampling displacement transducer of representative is used for numerical control scale-division class functional part Full Closed-loop Position feedbacks such as numerical control rotating platform.

Background technology

The time gate sensor be a kind of neoteric displacement transducer, utilize the time measurement locus, belong to static absolute type survey sensor.Based on the time grid of static measurement principle design,, there is not new measurement result output in certain period because the existence of measuring period (being the sampling period) can exist and measure the blind area.And digital control system is when carrying out full cut-off ring servocontrol, adopt hardware timer interrupt mode sampling location feedback information, the time grid and digital control system timing cycle inconsistent, and the time grid and digital control system adopt separately independently clock system respectively, two cover clock systems are also asynchronous.Therefore, grid can't be applied to dynamic continuous position feedback at present the time.

Summary of the invention

For with the time grid be used for numerical control scale-division class functional part Full Closed-loop Position such as numerical control rotating platform feedback, realize the high precision position servocontrol, displacement transducer is realized the method that numerical control rotating platform angular displacement prediction is measured when the invention provides a kind of the utilization.

The technical solution adopted for the present invention to solve the technical problems is: the time increase an intelligent interface unit between grid and numerical control (CNC) system, the absolute angle value that grid are measured during being input as of intelligent interface unit, be output as can with the increment type pulse signal of universal numerical control system interface, this intelligent interface unit according to the time grid current and in the past some discrete absolute angle measured values, the value of angular displacement of grid is predicted in following a period of time the time, generate the increment type continuous impulse signal of representative prediction value of angular displacement then by the time sequence, and, realize that the prediction of numerical control rotating platform angular displacement is measured according to the prediction error value of current actual measurement angle value correction previous time period.

The specific implementation process is as follows:

1. grid obtain the current absolute angle value of numerical control rotating platform every the time T once sampling time, and grid are at T when supposing _N-1Sampling constantly obtains an actual measurement angle value θ _N-1(absolute angle value), as shown in Figure 1.Utilize autoregressive model that front N time grid actual measurements angle value constantly carried out modeling, obtain from T _N-1Constantly to T _nThe value of angular displacement of the optimum linearity of numerical control rotating platform prediction constantly, and in the last measuring period (from T _N-2Constantly to T _N-1Prediction error value constantly) is revised, and prediction with the correction algorithm expression formula is:

Wherein,

For from T _N-1The time be carved into t _iPrediction value of angular displacement (increment size) constantly, as shown in Figure 2; θ _kRepresent T _kTime grid actual measurement angle values (absolute angle value) constantly;

Be inertial coefficient, require to satisfy condition With

Be T _N-1Prediction angle value (absolute angle value) constantly, its calculation expression is:

(θ _N-1'-θ _N-1) represent T _N-1Prediction error value is constantly promptly predicted the poor of angle value and actual measurement angle value; Δ t _i=t _i-T _N-1(0＜Δ t _i≤ T).

2. the prediction value of angular displacement that calculates according to formula (1), intelligent interface unit is inner, and to adopt crystal oscillator be clock reference, by the time sequence in next measuring period (from T _N-1Constantly to T _nConstantly) send equably and represent angular displacement Δ θ _i' the increment type pulse signal, pulse equivalency is 1 rad/pulse.

The time grid, intelligence interface and CNC system press the said process periodic duty, constitute Full Closed-loop Position Servo System.Prediction and modification method synoptic diagram are as shown in Figure 3.

The technical program can be summarized as: according to discrete measured value, generate the continuous space position signalling by the time sequence, and revise in real time.

The invention has the beneficial effects as follows, by designing an intelligence interface, utilize software that the displacement of following a period of time is predicted, predicted value is exported with the delta pulse signal form, can with the time grid be used for numerical control scale-division class functional part Full Closed-loop Position such as numerical control rotating platform feedback, required hardware is less, and function is mainly realized by software.

Description of drawings

The present invention is further described below in conjunction with drawings and Examples.

Fig. 1 is a technical scheme work synoptic diagram of the present invention.

Grid position feedback working timing figure when Fig. 2 is.

Fig. 3 is prediction and modification method schematic block diagram.

Fig. 4 is the structured flowchart of a kind of specific implementation of the present invention.

Fig. 5 is an arm processor interrupt service routine process flow diagram.

Embodiment

Realization below in conjunction with concrete hardware and software explanation the inventive method:

Referring to Fig. 4, the time grid adopt digital signal processor DSP (U1) deal with data, its concrete model is TMS320VC33.U1 /STRB and PAGE3 end by or door U31, the output terminal of U31 inserts the input end of rejection gate U32, the A0 end of another input termination U1 of U32, the output terminal of U32 divide EINT3 end that two-way inserts U1 respectively and the LOCK of latch U33 to hold.32 single data incoming line D31～D0 of U33 link to each other with 32 data lines D31～D0 of U1 successively, the 32 single data output lines 031～00 of U33 link to each other with the Data In-Line D15～D0 of two 16 tristate bus line impact dampers (U34 and U35) respectively, and the DOL Data Output Line 015～00 of U34 and U35 all connects P0.17～P0.2 end of arm processor LPC2138 (U2).Output enable end/En of U34 and output enable end/En of U35 link to each other with the P1.16 end with the P1.17 of U2 respectively.U31, U32, U33, U34 and U35 are integrated in a programmable logic chip CycloneII (U3) inside.

Be that example describes implementation procedure of the present invention in detail to get N=7 below.The time grid obtain an actual measurement angle value θ k every a measuring period, the D31～D0 by U1 holds output, concrete output format is: D31～D16 end output degree value, D15～D8 end output score value, D7～D0 end output second value.Adopt simultaneously a DSP write operation instruction control U1 /STRB ,/state of PAGE3 and A0 end, produce a positive pulse, at the rising edge of pulse the angle value of D31～D0 output of U1 is latched into 031～00 end of U33, triggers U2 at the negative edge of pulse and interrupt.In the arm processor master routine, the mode that instruction U2 response interruption is set by the interrupt response mode is set to the triggering of pulse negative edge, and tax sampling number k initial value is 0.As shown in Figure 5, in the arm processor interrupt service routine, U2 at first utilizes bit manipulation instruction control P1.16 and P1.17 end state to read in 32 θ from P0.17～P0.2 end at twice _kThe value, after with θ _kValue is stored in the data-carrier store that U2 inside carries, and the k value is increased by 1, and when k≤6, the arm processor interrupt service routine only reads and store θ _kValue is not done other operation.U2 responds to have no progeny in 7 times and collects θ like this ₀, θ ₁, θ ₂..., θ ₆Deng 7 data.Behind U2 the 8th secondary response interrupt service routine, at first read and store T with aforementioned the same manner ₇Time grid actual measurements angle value θ constantly ₇At this moment k=7 after value, k value increase by 1, k satisfies condition〉6, the U2 interrupt service routine turns to carry out and utilizes formula (1) calculating from T ₇Constantly to t _iConstantly predict value of angular displacement Δ θ _i', referring to Fig. 5.Get

, T=1000 μ s, θ ₇'=θ ₇, then formula (1) can be written as:

${\mathrm{\Δ\θ}}_i\′=\frac{\underset{k=1}{\overset{7}{\mathrm{\Σ}}}\frac{1}{7}({\mathrm{\θ}}_k-{\mathrm{\θ}}_{k-1})-({\mathrm{\θ}}_7\′-{\mathrm{\θ}}_7)}{1000}\mathrm{\Δ}{t}_i,---\left(3\right)$

Calculate from T according to formula (3) ₇Constantly to t _iPrediction angular displacement constantly

0＜Δ t in the formula _i≤ 1000, i=1,2 ..., 1000, adopt pulse width modulation mode (PWM mode) output representative continuously then

The pulse signal of angle, pulse equivalency are 1 rad/pulse.If angle value increases gradually, from the PWM1 end output pulse signal of U2; If angle value reduces gradually, then the PWM2 from U2 holds output pulse signal.When the absolute angle value is zero, from zero signal of P0.31 end output of U2.

Behind U2 the 9th secondary response interrupt service routine, at first still read and store T with aforementioned the same manner ₈Time grid actual measurements angle value θ constantly ₈Value utilizes formula (2) to calculate T then ₈Prediction angle value θ constantly ₈', concrete calculation expression is:

${\mathrm{\θ}}_8\′=\underset{k=1}{\overset{7}{\mathrm{\Σ}}}\frac{1}{7}({\mathrm{\θ}}_k-{\mathrm{\θ}}_{k-1})-{\mathrm{\θ}}_7\′+2{\mathrm{\θ}}_7,---\left(4\right)$

Utilize formula (1) to calculate again from T ₈Constantly to t _iConstantly predict value of angular displacement Concrete calculation expression is:

${\mathrm{\Δ\θ}}_i\′=\frac{\underset{k=2}{\overset{8}{\mathrm{\Σ}}}\frac{1}{7}({\mathrm{\θ}}_k-{\mathrm{\θ}}_{k-1})-({\mathrm{\θ}}_8\′-{\mathrm{\θ}}_8)}{1000}\mathrm{\Δ}{t}_i,---\left(5\right)$

Similarly adopt the PWM mode to export the representative angular displacement continuously at last

Pulse signal.

Arm processor U2 is each later on to interrupt, and all interrupts same works by above-mentioned the 9th secondary response.

Claims (3)

1. a displacement transducer when utilizing is realized the method that numerical control rotating platform angular displacement prediction is measured, it is characterized in that: the time increase an intelligent interface unit between grid and the digital control system, the absolute angle value that grid are measured during being input as of intelligent interface unit, be output as can with the increment type pulse signal of universal numerical control system interface; This intelligent interface unit according to the time grid current and in the past some discrete absolute angle measured values, the value of angular displacement of grid is predicted in following a period of time the time, generate the increment type continuous impulse signal of representative prediction angle value then by the time sequence, and, realize that the prediction of numerical control rotating platform angular displacement is measured according to the prediction error value of current actual measurement angle value correction previous time period.

2, displacement transducer is realized the method that numerical control rotating platform angular displacement prediction is measured during according to claim 1 the utilization, it is characterized in that predicting that measuring process is as follows:

1. grid obtain the current absolute angle value of numerical control rotating platform every the time T once sampling time, and grid are at T when establishing _N-1Sampling constantly obtains an actual measurement angle value θ _N-1, i.e. absolute angle value, intelligent interface unit utilizes autoregressive model that front N time grid actual measurements angle value constantly carried out modeling, obtains from T _N-1Constantly to T _nThe optimum linearity of numerical control rotating platform is predicted value of angular displacement constantly, and the prediction error value in the last measuring period is revised, and be from T a described last measuring period _N-2Constantly to T _N-1Constantly, prediction with the correction algorithm expression formula is:

Wherein,

For from T _N-1The time be carved into t _iPrediction value of angular displacement constantly, i.e. increment size; θ _kRepresent T _kTime grid actual measurements angle value constantly, i.e. absolute angle value; Be inertial coefficient, require to satisfy condition

θ _N-1' be T _N-1Prediction angle value constantly, i.e. absolute angle value, its calculation expression is:

θ _N-1'-θ _N-1Represent T _N-1Prediction error value is constantly promptly predicted the poor of angle value and actual measurement angle value; Δ t _i=t _i-T _N-1, 0＜Δ t _i≤ T;

2. the prediction value of angular displacement that calculates according to formula (1), intelligent interface unit is inner, and to adopt crystal oscillator be clock reference, by the time sequence in next measuring period, promptly from T _N-1Constantly to T _nConstantly, send the representative angle equably

The increment type pulse signal give digital control system, pulse equivalency is 1 rad/pulse;

The time grid, intelligent interface unit and digital control system press the said process periodic duty, constitute Full Closed-loop Position Servo System.

3, displacement transducer is realized the method that numerical control rotating platform angular displacement prediction is measured during according to claim 1 and 2 the utilization, it is characterized in that: intelligent interface unit is finished prediction and correction algorithm by microprocessor software, adopts hardware pulse width modulation mode output increment formula pulse signal.

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