CN100589057C - Control device of temperature of tube core of laser based on SCM and its control flow - Google Patents

Abstract

The invention discloses a laser tube core temperature controller and control flow path based on the single chip machine, it relates to a laser tube core temperature controller and programming with singlechip. The invention comprises singlechip (1), analogue/digital converter (2), digital/analogue converter (3), driver (4), laser (5), temperature sensor (6), refrigerator (7); or the temperature sensor (6) and refrigerator (7) are located near the laser (5), or the temperature sensor (6) and refrigerator (7) are integrated in the laser (5); the temperature sensor (6), the analogue/digital converter (2), the singlechip (1), the digital/analogue converter (3), the driver (4) and the refrigerator (7) are connected in turn; the driver (4) is connected with the analogue/digital converter (2). Theinvention adopts the single chip machine to intelligent control, the digit PID algorithm is also adopted, the control accuracy is high; it adopts the integrated chip, so the design is simple; the cost is low.

Description

SCM Based control device of temperature of tube core of laser and control flow thereof

Technical field

This explanation relates to a kind of control device of temperature of tube core of laser and Single Chip Microcomputer (SCM) program design, relates in particular to a kind of SCM Based control device of temperature of tube core of laser and control flow thereof.

Background technology

In the Optical Fiber Transmission dwdm system, for the optical wavelength that guarantees the laser instrument emission is stablized, need the laser tube core temperature to remain unchanged in the course of the work, so a lot of laser instruments are inner integrated refrigerator and temperature sensor, adopt outside Tec Driver output refrigerator drive current, reach the purpose of the cooling that heats up.Usually way was to adopt complicated control circuit according to temperature control refrigeration electric current in the past, this way circuit complexity, and control accuracy is not high, and operating temperature range is also limited.

In engineering reality, the regulator control law that is most widely used is ratio, integration, differential control, is called for short PID control, claims PID to regulate again.The PID controller existing so far nearly 70 years history of coming out, it is simple in structure with it, good stability, reliable operation, easy to adjust and become one of major technique of Industry Control.When the structure and parameter of controlled device can not be on top of, or when can not get precise math model, when other technology of control theory was difficult to adopt, the structure and parameter of system controller must rely on experience and field adjustable to determine, at this moment the thereof using PID control technology is the most convenient.

Summary of the invention

This illustrative purposes just is to overcome the shortcoming and defect that prior art exists, and a kind of SCM Based control device of temperature of tube core of laser and control flow thereof are provided, and realizes that circuit is succinct, control effectively, and the degree of accuracy height is used and made things convenient for.

This illustrative purposes is achieved in that

One, hardware configuration:

As Fig. 1, this explanation is made up of single-chip microcomputer 1, analog to digital converter (ADC) 2, digital to analog converter (DAC) 3, driver (Tec Driver) 4, laser instrument 5, temperature sensor 6, refrigerator 7;

Or near laser instrument 5, be provided with temperature sensor 6 and refrigerator 7, or at laser instrument 5 inner integrated temperature sensor 6 and refrigerators 7;

Temperature sensor 6, analog to digital converter 2, single-chip microcomputer 1, digital to analog converter 3, driver 4, refrigerator 7 connect successively;

Driver 4 is connected with analog to digital converter 2.

Two, principle of work

Temperature sensor 6 is that voltage signal is delivered to analog to digital converter 2 with temperature inversion, and analog to digital converter 2 is converted into digital quantity with voltage, and single-chip microcomputer 1 reads the digital quantity that analog to digital converter 2 transforms, through calculating the die temperature that can obtain laser instrument 1; Go out the controlled quentity controlled variable of corresponding driving device 4 then by the digital PID algorithm computation; Single-chip microcomputer 1 linking number weighted-voltage D/A converter 3 makes it export the corresponding refrigeration electric current of these controlled quentity controlled variable Control Driver 4 outputs and gives refrigerator 7, thereby reaches the constant effect of die temperature that keeps laser instrument 5; Driver 4 reports single-chip microcomputer 1 with refrigeration size of current at this moment by analog to digital converter 2, and single-chip microcomputer 1 can know that the refrigeration size of current of this moment is excessive to prevent the refrigeration electric current, guarantees laser instrument 1 trouble free service.

Three, digital PID algorithm

In the simulation system, the pid algorithm expression formula is:

$\mathrm{Pt}=\mathrm{Kp}\·[e\left(t\right)+\frac{1}{\mathrm{Ti}}\∫e\left(\mathrm{dt}\right)+\mathrm{Td}\·\frac{\mathrm{de}\left(t\right)}{d\left(t\right)}]$

Because Single-chip Controlling is a kind of controlling of sampling, it can only come the calculation control amount according to the deviate of sampling instant, therefore at first will carry out discretize and handle, and obtains formula and is:

(T is the sampling period)

If Ki=Kp*T/Ti, Kd=Kp*Td/T.

Proportional: Pp (k)=Pp (k)=KpE (k)

Integral:

Differential term: Pd (k)=Kd[E (k)-E (k-1)]

Be the algorithm of digital PID, Kp wherein, Ki, Kd are crucial 3 parameters.

Apply to native system, then P (k) is the refrigeration current value that at every turn needs setting, E (k)=M (k)-R, and E (k) is for measuring the difference of temperature and design temperature, and M (k) measures temperature value for this, and R is for presetting the temperature value that need reach.(Kp Ki.Kd), only need configure the stable control that temperature value when stablizing can be realized temperature must to reach the parameter value of desirable state of a control by experiment.

Four, control flow

As Fig. 2, control flow divides three parts: master routine part, PID control section and timer break in service part.

1, master routine

As Fig. 2 .1, master routine is followed successively by: beginning A, and initial configuration B, ADC sign zero clearing and timer interrupt C, ADC flag set D measures temperature voltage by ADC, and calculates temperature value E, and PID controls F, DAC G is set, measures refrigeration current feedback value H, clear ADC sign I by ADC;

In detail, beginning A carries out initial configuration B to single-chip microcomputer, comprises clock, port, timer etc., and to some variable assignments, as the Several Parameters of PID control, integral initial value etc.; Remove the ADC zone bit then, and allow timer to interrupt C; Enter main loop body, check that whether ADC indicates set D, if set, then measure temperature voltage value this moment by ADC, and calculate current temperature value E according to the corresponding relation of temperature and voltage, adopt pid control algorithm F then, needing to obtain the DAC magnitude of voltage of setting, be set to the output G of DAC; After setting is finished, measure the value of feedback H of the electric current that freezes this moment by ADC, the electric current that prevents to freeze surpasses safe range; Remove ADC sign I at last, once the sampling circulation is finished.

2, PID control

As Fig. 2 .2, the PID control program be input as temperature value, be output as the DAC controlled quentity controlled variable;

PID control is followed successively by: calculation deviation F1, calculate controlled quentity controlled variable F2 according to the PID formula, and controlled quentity controlled variable surpasses maximal value F3, and controlled quentity controlled variable is made as maximal value F4, and controlled quentity controlled variable is less than minimum value F5, and controlled quentity controlled variable is made as minimum value F6, exports controlled quentity controlled variable F7 at last.

In detail, at first the temperature value of input is obtained departure F1 with temperature value last time, obtain the controlled quentity controlled variable F2 of this moment then according to the PID formula; Relatively whether controlled quentity controlled variable surpasses maximal value F3, if surpass maximal value, then controlled quentity controlled variable is made as maximal value F4; Then relatively controlled quentity controlled variable whether less than minimum value F5, if less than minimum value then be made as minimum value F6.Export controlled quentity controlled variable F7 at last.

3, timer interrupts

As Fig. 2 .3, timer interrupts being followed successively by: clear interrupt identification S1, ADC flag set S2, the timer S3 that resets, finish S4.

In detail, the set to the ADC sign is finished in the timer break in service, and the expression employing cycle has arrived, and can sample next time.Interrupt routine is interrupting according to predefined timing cycle generation interrupt request, making CPU enter interrupt service routine under the situation about allowing.After entering interrupt service routine, at first remove interrupt identification S1,, and, withdraw from interrupt service routine S4 then the counter reset S3 of timer then with ADC flag set S2.

In the time of utilization the method, in order to reach reasonable control effect, key is the setting of the controlled variable of PID, can be according to test, constantly change the sampling period (being timer cycle), scale-up factor (Pk), integral coefficient (Pi) and differential coefficient (Pd) obtain more satisfactory control effect.

This explanation has following advantage and good effect:

1,, adopts the digital PID algorithm, the control accuracy height by the single-chip microcomputer Based Intelligent Control.

2, adopt integrated chip, simplicity of design, circuit is succinct.

3, with low cost.

Description of drawings

Fig. 1-this control device structured flowchart;

The main flow chart of this control program of Fig. 2 .1-;

The PID control flow chart of this control program of Fig. 2 .2-;

The timer of this control program of Fig. 2 .3-interrupts process flow diagram.

Wherein:

The 1-single-chip microcomputer;

2-analog to digital converter (ADC);

3-digital to analog converter (DAC);

4-driver (Tec Driver);

The 5-laser instrument;

The 6-temperature sensor;

The 7-refrigerator.

Embodiment

One, each parts

1, single-chip microcomputer 1

Single-chip microcomputer 1 is selected the C8051F330 of Silabs for use.

2, analog to digital converter 2

Analog to digital converter 2 is selected 10 inner integrated Precision A C of C8051F330 for use.

3, digital to analog converter 3

Digital to analog converter 3 is selected 10 inner integrated precision current-output type DAC of C8051F330 for use.

4, the refrigerator driver 4

Refrigerator driver 4 is selected the MAX8521 of Maxim for use.

5, laser instrument 5

Laser instrument 5 is selected the TLA10X of Apogee for use.

6, temperature sensor 5

The inner integrated NTC type thermistor of TLA10X is as temperature sensor.

Two, integrated

Because at present a lot of all integrated ADC in single-chip microcomputer inside and DAC, so above-mentioned several functional modules are can simple several chips integrated, make circuit more succinct, improved reliability.

Claims (2)

1, a kind of SCM Based control device of temperature of tube core of laser is characterized in that:

Form by single-chip microcomputer (1), analog to digital converter (2), digital to analog converter (3), driver (4), laser instrument (5), temperature sensor (6), refrigerator (7);

Or near laser instrument (5), be provided with temperature sensor (6) and refrigerator (7), or laser instrument (5) inner integrated temperature sensor (6) and refrigerator (7);

Temperature sensor (6), analog to digital converter (2), single-chip microcomputer (1), digital to analog converter (3), driver (4), refrigerator (7) connect successively;

Driver (4) is connected with analog to digital converter (2);

Temperature sensor (6) is that voltage signal is delivered to analog to digital converter (2) with temperature inversion, analog to digital converter (2) is converted into digital quantity with voltage, single-chip microcomputer (1) reads the digital quantity that analog to digital converter (2) transforms, through calculating the die temperature that can obtain laser instrument (1); Go out the controlled quentity controlled variable of corresponding driving device (4) then by the digital PID algorithm computation; Single-chip microcomputer (1) linking number weighted-voltage D/A converter (3) makes it export the corresponding refrigeration electric current of this controlled quentity controlled variable Control Driver (4) output and gives refrigerator (7), thereby reaches the constant effect of die temperature that keeps laser instrument (5); Driver (4) reports single-chip microcomputer (1) with refrigeration size of current at this moment by analog to digital converter (2), and single-chip microcomputer (1) can know that the refrigeration size of current of this moment is excessive to prevent the refrigeration electric current, guarantees laser instrument (1) trouble free service;

Described single-chip microcomputer 1 is selected the C8051F330 of Silabs for use;

Described analog to digital converter 2 is selected 10 inner integrated Precision A C of C8051F330 for use;

Described digital to analog converter 3 is selected 10 inner integrated precision current-output type DAC of C8051F330 for use;

Described refrigerator driver 4 is selected the MAX8521 of Maxim for use;

Described laser instrument 5 is selected the TLA10X of Apogee for use;

Described TLA10X is inner integrated NTC type thermistor is as temperature sensor.

2, a kind of control flow of SCM Based control device of temperature of tube core of laser is characterized in that:

1. master routine is followed successively by: beginning (A), initial configuration (B), ADC sign zero clearing and timer interrupt (C), ADC flag set (D), measure temperature voltage and calculate temperature value (E) by ADC, PID controls (F), and DAC (G) is set, measure refrigeration current feedback value (H), clear ADC sign (I) by ADC;

2. the RID control program be input as temperature value, be output as the DAC controlled quentity controlled variable;

PID control is followed successively by: calculation deviation (F1), calculate controlled quentity controlled variable (F2) according to the PID formula, and controlled quentity controlled variable surpasses maximal value (F3), controlled quentity controlled variable is made as maximal value (F4), controlled quentity controlled variable is less than minimum value (F5), and controlled quentity controlled variable is made as minimum value (F6), exports controlled quentity controlled variable (F7) at last;

3. timer interrupts being followed successively by: clear interrupt identification (S1), and ADC flag set (S2), timer resets (S3), finishes (S4).

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