CN104917436A - Adaptive second-order terminal sliding-mode control system and method of permanent magnet linear synchronous motor - Google Patents

Abstract

The invention relates to an adaptive second-order terminal sliding-mode control system and method. On the basis of comparison of a given speed signal and a feedback speed signal of a servo system of a permanent magnet linear synchronous motor, an error amount is obtained; a terminal sliding mode surface is designed based on the error amount and a super-coiling algorithm controlled by the second-order sliding mode is used for realizing the input of a speed controller; and an adaptive control way is introduced to carry out dynamic adjustment on a control gain of the super-coiling algorithm. Therefore, the rapid response of the system is realized; and the system robustness is improved. With the control method, the system can have the high robustness and the system buffeting can be weakened effectively.

Description

The Adaptive Second-Order TSM control system and method for permanent magnet linear synchronous motor

Technical field

The invention belongs to fields of numeric control technique, particularly a kind of Adaptive Second-Order TSM control system and method for permanent magnet linear synchronous motor.

Background technology

Numeric Control Technology believes by numeral the technology that controls the Machine Movement Process of control object, and numerical control equipment take Numeric Control Technology as the electromechanical integrated product that the infiltration of new technology to traditional manufacturing industry and emerging manufacturing industry of representative is formed.Modern NC Machine Tool and the most basic difference of early stage Digit Control Machine Tool are that its process velocity and machining accuracy there occurs great variety, improve nearly thousand times respectively.Because high speed, high accuracy process technology greatly can improve processing speed, the quality improving product and class, the raising market competitiveness, thus, with one of high-speed cutting, high speed feed and high manufacturing accuracy High-speed Machining Technology important development trend having become modern Computerized Numerical Control processing technology that is principal character.

For a long time, the feed system of Digit Control Machine Tool mainly " electric rotating machine+ball-screw ", this servo form structure is complicated, and there is drive gap and strain etc. and cause the series of problems such as motion delay and other nonlinearity erron, is difficult to obtain very high acceleration and positioning precision.Adopt the direct driving technologies of PMLSM to some extent solve the problems referred to above, which eliminate the harmful effect that mechanical transmission mechanism brings, in high accuracy, high-speed response, the application of Fine Feed servo system, there is very large advantage.But, due to the load of linear motor Direct driver, the uncertain factor such as Parameter Perturbation, load disturbance of system is directly reflected on the mover of linear electric motors by having no damply, make system to load disturbance and Parameters variation all very sensitive, so require that system has stronger robustness, this has higher requirement to linear electric motor controller.

Scholars propose some control methods, as adopted robust control theory CONTROLLER DESIGN, system can be made to have good robustness, but have certain conservative; Adopt Adaptive Control Theory CONTROLLER DESIGN, effectively can overcome the impact of Parameters variation on system, but then poor effect, external disturbance frequency very fast at Parameters variation is high.Adopt sliding mode control theory CONTROLLER DESIGN, there is strong robustness, realize simple advantage, but can chattering phenomenon be caused due to the discontinuity of its control action.Adopt TSM control Theoretical Design controller, improve the convergence property of system, but there is singularity problem.

Summary of the invention

Goal of the invention

For the deficiency existed in existing control technology, the invention provides a kind of Adaptive Second-Order TSM control system and method for permanent magnet linear synchronous motor, Second Order Sliding Mode Control, TSM control are combined with auto-adaptive control scheme, finally realize the quick response that namely object of the present invention realizes system, improve the robustness of system.

Technical scheme

An Adaptive Second-Order TSM control system for permanent magnet linear synchronous motor, is characterized in that: this system comprises main circuit, control circuit and control object three part; Control circuit comprises DSP, position and velocity checking circuits, current detection circuit, optical coupling isolation circuit, drive circuit and fault detect and protective circuit; The QEP port link position of DSP and velocity checking circuits, the ADC port of DSP connects current detection circuit, the PWM port of DSP is connected optical coupling isolation circuit with PDPINT port, and optical coupling isolation circuit connects drive circuit and fault detect and protective circuit, and drive circuit connects main circuit; Main circuit comprises regulating circuit, rectification filtering unit and IPM inversion unit; Control object is three-phase permanent linear synchronous generator, and fuselage is equipped with grating scale; Regulating circuit connects rectification filtering unit, and rectification filtering unit connects IPM inversion unit, and IPM inversion unit connects three-phase permanent linear synchronous generator.

The SCI port of DSP connects host computer, and the SPI port of DSP connects display circuit, and the GPIO port of DSP connects I/O interface circuit; Fault detect and protective circuit connection control power supply.

A kind of control method of Adaptive Second-Order TSM control system of permanent magnet linear synchronous motor as above, it is characterized in that: obtain the margin of error according to PM linear servo system given speed signal and feedback speed signal subtraction, with this margin of error design terminal sliding-mode surface and using the super-twisting algorithm of Second Order Sliding Mode Control as the input of speed control, and introduce adaptive control dynamic adjustments is carried out to the ride gain of super-twisting algorithm.

Choose terminal sliding mode face;

System tracking error is e=v ^*-v, wherein, v ^*for the set-point of v;

The terminal sliding mode variable of system is:

$\mathrm{\σ}=e\left(t\right)+\frac{1}{\mathrm{\ν}}{\left|\stackrel{\·}{e}\left(t\right)\right|}^{p/q}\mathrm{sgn}\left(\stackrel{\·}{e}\right(t\left)\right)$

Wherein, ν ∈ R ⁺, p, q are odd number, require that 1 < p/q < 2 is to meet the nonsingularity of sliding-mode surface.

Adopt the ride gain β of adaptive control to super-twisting algorithm to regulate, thus make sliding variable σ and the first derivative thereof of system be zero at Finite-time convergence;

Specific algorithm is as follows:

$\left\{\begin{array}{c}u=-\mathrm{\&alpha;}{\left|\mathrm{\&sigma;}\right|}^{1/2}\mathrm{sgn}\left(\mathrm{\&sigma;}\right)+v\\ \stackrel{\&CenterDot;}{v}=-\mathrm{\&beta;}\mathrm{sgn}\left(\mathrm{\&sigma;}\right)\end{array}\right.;$

Supercoil control algolithm makes system mode track at Finite-time convergence to the adequate condition of sliding-mode surface be:

$\{\begin{array}{c}\mathrm{\&beta;}>\frac{C}{K_m}>0\\ {\mathrm{\&alpha;}}^2\&GreaterEqual;\frac{4{\mathrm{CK}}_M(\mathrm{\&beta;}+C)}{{K_m}^3(\mathrm{\&beta;}-C)}\end{array};$

The adaptive law of the ride gain β of definition super-twisting algorithm is:

$\stackrel{\&CenterDot;}{\mathrm{\&beta;}}=\left\{\begin{array}{cc}k\left|\mathrm{\&sigma;}\right|\mathrm{sgn}\left(\right|\mathrm{\&sigma;}|-\mathrm{\&epsiv;}),& \mathrm{\&beta;}>\mathrm{\&gamma;}\\ \mathrm{\&gamma;},& \mathrm{\&beta;}\&le;\mathrm{\&gamma;}\end{array}\right.;$

Wherein, γ > 0, k > 0, ε > 0.

Program in control method call number signal processor realizes, and control program step is as follows:

Step 1 system initialization;

Step 2 allows TN1, TN2 to interrupt;

Step 3 starts T1 underflow and interrupts;

The initialization of step 4 routine data;

Step 5 opens total interruption;

Step 6 interrupt latency;

The sub-control program of step 7 TN1 interrupt processing;

Step 8 terminates;

Above-mentioned TN1 interrupt processing sub-control program step is as follows:

Step 1 T1 interrupts sub-control program;

Step 2 keeps the scene intact;

Step 3 judges whether given speed signal; Be enter step 4, otherwise enter step 10;

Step 4 current sample, CLARK converts, and PARK converts;

Step 5 judges whether to need speed to regulate; Otherwise enter step 7;

Step 6 speed regulates the sub-control program of interrupt processing;

Step 7 dq shaft current regulates;

Step 8 PARK inverse transformation;

Step 9 calculates CMPPx and PWM and exports;

Step 10 position, speed sampling;

Step 11 initial velocity program;

Step 12 restoring scene;

Step 13 interrupts returning.

Speed described in above-mentioned steps 6 regulates interrupt processing sub-control program step as follows:

Step 1 speed regulates interrupts sub-control program;

Step 2 reads encoder values;

Step 3 judges angle;

Step 4 calculating location and speed;

Step 5 execution speed controller;

The order of step 6 calculating current also exports;

Step 7 interrupts returning.

Advantage and effect

The present invention is a kind of Adaptive Second-Order TSM control system and method for permanent magnet linear synchronous motor, has the following advantages:

For permanent magnet linear synchronous motor (PMLSM) servo system, the present invention proposes a kind of Adaptive Second-Order TSM control system and method for permanent magnet linear synchronous motor.This control method solves the problem that original TSM control exists singularity in design.Utilize the supercoil control law of Second Order Sliding Mode, by the discontinuous control action of system in the higher differentiation of sliding variable, thus weaken system chatter.Introduce adaptive control and dynamic adjustments is carried out to the ride gain of super-twisting algorithm, to overcome the limitation that ride gain needs probabilistic boundary to determine, and then improve the control performance of system, finally realize the robustness that namely object of the present invention improves system, the buffeting of impair system.

Accompanying drawing explanation

Fig. 1 is Adaptive Second-Order TSM control device system block diagram of the present invention.

Fig. 2 is for realizing hardware system schematic diagram of the present invention.

Fig. 3 (a) electric machine control system main circuit schematic diagram.

Fig. 3 (b) A, B phase current sampling circuit schematic diagram.

Fig. 3 (c) grating scale signal sample circuit schematic diagram.

Fig. 3 (d) driving circuit principle figure.

Fig. 4 control system program.

The sub-control program flow chart of Fig. 5 T1 interrupt processing.

Fig. 6 speed regulates the sub-control program flow chart of interrupt processing.

Embodiment

The impact of the uncertain factor such as Parameters variation and load disturbance is subject to for permanent magnet linear synchronous motor (PMLSM) servo system, the invention provides a kind of Adaptive Second-Order TSM control system and method for permanent magnet linear synchronous motor, Second Order Sliding Mode Control, TSM control are combined with auto-adaptive control scheme, to compare with feedback speed signal according to PM linear servo system given speed signal and obtain the margin of error, with this margin of error design terminal sliding-mode surface, avoid singularity problem.Using the super-twisting algorithm of Second Order Sliding Mode Control as the input of speed control, and introduce adaptive control dynamic adjustments is carried out to the ride gain of super-twisting algorithm, finally realize the quick response that namely object of the present invention realizes system, improve the robustness of system.

Below in conjunction with accompanying drawing, the present invention is described further:

Fig. 1 is the theory diagram of the Adaptive Second-Order TSM control system of permanent magnet linear synchronous motor, wherein v ^*for the set-point of system speed, σ is the sliding formwork diverter surface relevant with systematic error, F _lfor load resistance, system tracking error is e=v ^*-v.

The terminal sliding mode variable of system is: $\mathrm{\&sigma;}=e\left(t\right)+\frac{1}{\mathrm{\&nu;}}{\left|\stackrel{\&CenterDot;}{e}\left(t\right)\right|}^{p/q}\mathrm{sgn}\left(\stackrel{\&CenterDot;}{e}\right(t\left)\right);$

Wherein, ν ∈ R ⁺, p, q are odd number, require that 1 < p/q < 2 is to meet the nonsingularity of sliding-mode surface.

Adopt the ride gain β of adaptive control to super-twisting algorithm to regulate, thus make sliding variable σ and the first derivative thereof of system be zero at Finite-time convergence;

Specific algorithm is as follows:

$\left\{\begin{array}{c}u=-\mathrm{\&alpha;}{\left|\mathrm{\&sigma;}\right|}^{1/2}\mathrm{sgn}\left(\mathrm{\&sigma;}\right)+v\\ \stackrel{\&CenterDot;}{v}=-\mathrm{\&beta;}\mathrm{sgn}\left(\mathrm{\&sigma;}\right)\end{array}\right.;$

Supercoil control algolithm makes system mode track at Finite-time convergence to the adequate condition of sliding-mode surface be:

$\{\begin{array}{c}\mathrm{\&beta;}>\frac{C}{K_m}>0\\ {\mathrm{\&alpha;}}^2\&GreaterEqual;\frac{4{\mathrm{CK}}_M(\mathrm{\&beta;}+C)}{{K_m}^3(\mathrm{\&beta;}-C)}\end{array};$

The adaptive law of the ride gain β of definition super-twisting algorithm is:

$\stackrel{\&CenterDot;}{\mathrm{\&beta;}}=\left\{\begin{array}{cc}k\left|\mathrm{\&sigma;}\right|\mathrm{sgn}\left(\right|\mathrm{\&sigma;}|-\mathrm{\&epsiv;}),& \mathrm{\&beta;}>\mathrm{\&gamma;}\\ \mathrm{\&gamma;},& \mathrm{\&beta;}\&le;\mathrm{\&gamma;}\end{array}\right.;$

Wherein, γ > 0, k > 0, ε > 0.

Fig. 2 is for realizing hardware system schematic diagram of the present invention.This system comprises main circuit, control circuit and control object three part; Control circuit comprises DSP, position and velocity checking circuits, current detection circuit, optical coupling isolation circuit, drive circuit and fault detect and protective circuit; The QEP port link position of DSP and velocity checking circuits, the ADC port of DSP connects current detection circuit, the PWM port of DSP is connected optical coupling isolation circuit with PDPINT port, and optical coupling isolation circuit connects drive circuit and fault detect and protective circuit, and drive circuit connects main circuit; Main circuit comprises regulating circuit, rectification filtering unit and IPM inversion unit; Control object is three-phase permanent linear synchronous generator, and fuselage is equipped with grating scale; Regulating circuit connects rectification filtering unit, and rectification filtering unit connects IPM inversion unit, and IPM inversion unit connects three-phase permanent linear synchronous generator.

The SCI port of DSP connects host computer, and the SPI port of DSP connects display circuit, and the GPIO port of DSP connects I/O interface circuit; Fault detect and protective circuit connection control power supply.

DSP adopts the TMS320F28335 chip of TI company.

Realize control system main circuit of the present invention as shown in Fig. 3 (a), regulating circuit adopts reverse voltage regulating module EUV-25A-II, can realize 0 ~ 220V and isolate pressure regulation.Rectification filtering unit adopts the uncontrollable rectification of bridge-type, and bulky capacitor filtering, coordinates suitable resistance capaciting absorpting circuit, can obtain the constant DC voltage needed for IPM work.IPM adopts Fuji company 6MBP50RA060 Intelligent Power Module, withstand voltage 600V, maximum current 50A, maximum operating frequency 20kHz.IPM with four groups independently 15V driving power power.Main power source input terminal (P, N), lead-out terminal (U, V, W), the main terminal screw carried is fixed, and can realize current delivery.P, N are the main power source input terminal after the rectifying conversion smothing filtering of frequency converter, and P is anode, and N is negative terminal, and the three-phase alternating current that inverter exports is connected to motor by lead-out terminal U, V, W.

The core of control circuit of the present invention is TMS320F28335 processor, and its supporting development board comprises the outer 256K*16 position RAM of traget ROM, analog interface, eCAN interface, serial boot ROM, user lamp, reset circuit, the asynchronous serial port that can be configured to RS232/RS422/RS485, SPI synchronous serial interface and sheet.

In actual control system, current sample adopts LEM company Hall current sensor LT58-S7.A, B phase current is detected by two Hall current sensors, obtain current signal, through current sampling circuit, convert the voltage signal of 0 ~ 3.3V to, the last binary number being converted to 12 precision by the A/D modular converter of TMS320LF2812, and be kept in numerical register.The current sampling circuit of A, B phase is as shown in Fig. 3 (b).Adjustable resistance VR2 conditioning signal amplitude, adjustable resistance VR1 conditioning signal side-play amount, by the adjustment to these two resistance, can adjust to 0 ~ 3.3V by signal, then is sent into AD0, AD1 pin of DSP.Voltage-stabiliser tube in figure is to prevent the signal sending into DSP more than 3.3V, causing DSP to be damaged by high pressure.Operational amplifier adopts OP27, and power supply connects positive and negative 15V voltage, at voltage and ground decoupling capacitor indirectly.Circuit input end connects capacitor filtering, to remove high-frequency signal interference, improves sampling precision.

The A phase that grating scale exports and B phase pulse signal will be isolated signal by rapid light coupling 6N137, then through bleeder circuit, signal level are converted to 3.3V by 5V, are finally connected to two-way quadrature coding pulse interface QEP1 and QEP2 of DSP.Circuit theory is as shown in Fig. 3 (c).Fig. 3 (d) is the drive circuit of invented hardware system, linear electric motors drive circuit mainly comprises an Intelligent Power Module, that the present invention selects is IRAMSl0UP60B, and it is applicable in the motor of relatively high power, and the power of motor scope that it can drive is 400W ~ 750W; Primarily of the three-phase bridge circuit that 6 IGBT are formed, the pwm control signal that on control board, dsp chip produces is input to power model, control the shutoff of 3 brachium pontis, produce appropriate drive voltage, HIN1 and LIN1 in driving linear electric motors motion diagram is the control signal of the upper and lower bridge arm of first-phase respectively, and they are all Low level effectives.The operating voltage VDD of IRAMSl0UP60B is 15V, VSS is earth terminal, in order to reach good decoupling effect, adds two decoupling capacitors in parallel at these two ends.Because the PWM ripple signal of input is digital signal, and IRAMS10UP60B does not possess the function digital signal and power signal isolation, therefore need to add the isolation of glazing misfortune before the input control signal of IRAMS10UP60B, in figure, namely TLPll3 achieves the function pwm signal of input being converted into analog signal, is then input to the control signal input of corresponding brachium pontis.The bootstrap capacitor of a 2.2uF is added respectively at output u, v, w of three-phase voltage.When Itrip port is low level, chip normally works, and the control signal inputted when the upper part of brachium pontis is low level, and time lower part is high level, this has output voltage mutually; When upper be high level, lower for output voltage time low level be zero; Both for low level situation does not allow appearance, short circuit can be caused like that, burn chip.When Itrip port is high level, chip does not work, and does not have voltage to export, and therefore add a pull down resistor in circuit and make Itrip port be low level, such power model can normally work.Power chip self had gentle overcurrent protection, can play the effect of self-protection when circuit occurs abnormal.

Fig. 4 is that control system program is finally realized by dsp processor, and step is as follows:

Step 1 system initialization;

Step 2 allows TN1, TN2 to interrupt;

Step 3 starts T1 underflow and interrupts;

The initialization of step 4 routine data;

Step 5 opens total interruption;

Step 6 interrupt latency;

The sub-control program of step 7 TN1 interrupt processing;

Step 8 terminates;

Fig. 5 is the sub-control program flow chart of T1 interrupt processing, and step is as follows:

Step 1 T1 interrupts sub-control program;

Step 2 keeps the scene intact;

Step 3 judges whether given speed signal; Be enter step 4, otherwise enter step 10;

Step 4 current sample, CLARK converts, and PARK converts;

Step 5 judges whether to need speed to regulate; Otherwise enter step 7;

Step 6 speed regulates the sub-control program of interrupt processing;

Step 7 dq shaft current regulates;

Step 8 PARK inverse transformation;

Step 9 calculates CMPPx and PWM and exports;

Step 10 position, speed sampling;

Step 11 initial velocity program;

Step 12 restoring scene;

Step 13 interrupts returning.

Fig. 6 is that speed regulates the sub-control program flow chart of interrupt processing, and step is as follows:

Step 1 speed regulates interrupts sub-control program;

Step 2 reads encoder values;

Step 3 judges angle;

Step 4 calculating location and speed;

Step 5 execution speed controller;

The order of step 6 calculating current also exports;

Step 7 interrupts returning.

Claims (8)

1. an Adaptive Second-Order TSM control system for permanent magnet linear synchronous motor, is characterized in that: this system comprises main circuit, control circuit and control object three part; Control circuit comprises DSP, position and velocity checking circuits, current detection circuit, optical coupling isolation circuit, drive circuit and fault detect and protective circuit; The QEP port link position of DSP and velocity checking circuits, the ADC port of DSP connects current detection circuit, the PWM port of DSP is connected optical coupling isolation circuit with PDPINT port, and optical coupling isolation circuit connects drive circuit and fault detect and protective circuit, and drive circuit connects main circuit; Main circuit comprises regulating circuit, rectification filtering unit and IPM inversion unit; Control object is three-phase permanent linear synchronous generator, and fuselage is equipped with grating scale; Regulating circuit connects rectification filtering unit, and rectification filtering unit connects IPM inversion unit, and IPM inversion unit connects three-phase permanent linear synchronous generator.

2. the Adaptive Second-Order TSM control system of permanent magnet linear synchronous motor according to claim 1, is characterized in that: the SCI port of DSP connects host computer, and the SPI port of DSP connects display circuit, and the GPIO port of DSP connects I/O interface circuit; Fault detect and protective circuit connection control power supply.

3. the control method of the Adaptive Second-Order TSM control system of a permanent magnet linear synchronous motor as claimed in claim 1, it is characterized in that: obtain the margin of error according to PM linear servo system given speed signal and feedback speed signal subtraction, with this margin of error design terminal sliding-mode surface and using the super-twisting algorithm of Second Order Sliding Mode Control as the input of speed control, and introduce adaptive control dynamic adjustments is carried out to the ride gain of super-twisting algorithm.

4. the Adaptive Second-Order TSM control method of permanent magnet linear synchronous motor according to claim 3, is characterized in that: choose terminal sliding mode face;

System tracking error is e=v ^*-v, wherein, v ^*for the set-point of v;

The terminal sliding mode variable of system is:

Wherein, ν ∈ R ⁺, p, q are odd number, require that 1 < p/q < 2 is to meet the nonsingularity of sliding-mode surface.

5. the Adaptive Second-Order TSM control method of permanent magnet linear synchronous motor according to claim 3, is characterized in that: adopt the ride gain β of adaptive control to super-twisting algorithm to regulate, thus make sliding variable σ and the first derivative thereof of system be zero at Finite-time convergence;

Specific algorithm is as follows:

Supercoil control algolithm makes system mode track at Finite-time convergence to the adequate condition of sliding-mode surface be:

The adaptive law of the ride gain β of definition super-twisting algorithm is:

Wherein, γ > 0, k > 0, ε > 0.

6. the Adaptive Second-Order TSM control method of permanent magnet linear synchronous motor according to claim 3, is characterized in that: the program in control method call number signal processor realizes, and control program step is as follows:

Step 1 system initialization;

Step 2 allows TN1, TN2 to interrupt;

Step 3 starts T1 underflow and interrupts;

The initialization of step 4 routine data;

Step 5 opens total interruption;

Step 6 interrupt latency;

The sub-control program of step 7 TN1 interrupt processing;

Step 8 terminates.

7. the Adaptive Second-Order TSM control method of permanent magnet linear synchronous motor according to claim 6, is characterized in that: TN1 interrupt processing sub-control program step is as follows:

Step 1 T1 interrupts sub-control program;

Step 2 keeps the scene intact;

Step 3 judges whether given speed signal; Be enter step 4, otherwise enter step 10;

Step 4 current sample, CLARK converts, and PARK converts;

Step 5 judges whether to need speed to regulate; Otherwise enter step 7;

Step 6 speed regulates the sub-control program of interrupt processing;

Step 7 dq shaft current regulates;

Step 8 PARK inverse transformation;

Step 9 calculates CMPPx and PWM and exports;

Step 10 position, speed sampling;

Step 11 initial velocity program;

Step 12 restoring scene;

Step 13 interrupts returning.

8. the Adaptive Second-Order TSM control method and apparatus of permanent magnet linear synchronous motor according to claim 7, is characterized in that: the speed described in step 6 regulates interrupt processing sub-control program step as follows:

Step 1 speed regulates interrupts sub-control program;

Step 2 reads encoder values;

Step 3 judges angle;

Step 4 calculating location and speed;

Step 5 execution speed controller;

The order of step 6 calculating current also exports;

Step 7 interrupts returning.