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IEEE CDC 2002 T W: Fractional Calculus Applications in Automatic Control and Robotics On Fractional PID Controllers: A Frequency Domain Approach Blas M. Vinagre Escuela de Ingenierías Industriales, UEX, Badajoz, Spain I. Podlubny, L. Dorcak BERG Faculty, Technical University of Kosice, Kosice, Slovak Rep. V. Feliu E. T. S. Ingenieros Industriales, UCLM, Ciudad Real, Spain
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On Fractional PID Controllers a Frequency Domain Approach

Oct 29, 2015

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On Fractional PID Controllers a Frequency Domain Approach
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Page 1: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

On Fractional PID Controllers:A Frequency Domain Approach

Blas M. VinagreEscuela de Ingenierías Industriales, UEX, Badajoz, Spain

I. Podlubny, L. DorcakBERG Faculty, Technical University of Kosice, Kosice, Slovak Rep.

V. FeliuE. T. S. Ingenieros Industriales, UCLM, Ciudad Real, Spain

Page 2: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Fractional Calculus Fundamentals (I)

■ Fractional integral (Riemann-Liouville)

■ Fractional derivative (Riemann-Liouville)

Page 3: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Fractional Calculus Fundamentals (II)

■ Fractional Derivative (Gründwald-Letnikov)

■ Laplace Transforms

Page 4: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Classical PID

■ Equations

Page 5: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Classical PID

■ Frequency response

Page 6: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Fractional PID

■ Equations

Page 7: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Fractional PID

■ Frequency response

Page 8: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Fractional PID

■ Fractional ID controller

Page 9: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Fractional PID

■ PID plane

Page 10: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Illustrative examples

■ Example 1– Real system transfer function

– Approximated transfer function

Page 11: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Illustrative examples

■ Example 1– Fractional PD controller

Page 12: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Illustrative examples

■ Example 1– PD controller

Page 13: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Example 1■ Step responses

Page 14: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Illustrative examples

■ Example 2: DC Motor– Transfer function:

– Specifications: Phase Margin=60º, independent of the payload changes.

Page 15: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Example 2

■ Fractional controller

Page 16: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Example 2■ Step response

Page 17: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Ideas for further work

■ On tuning– Generalize some methods for using the

new possibilities■ On realizations:

– The problem of memory

Page 18: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

On realizations

■ Analog realizations– Partial fractions expansions, continued

fractions expansions, etc.– Rational function interpolation– Fitting or identification

■ Analog circuit

Page 19: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Digital realizations

■ The “short memory” principle

Page 20: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Digital realizations

■ The “short memory” principle

Page 21: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Digital realizations■ Other approximations

– Gründwald-Letnikov, equivalent to

– Using TR and CFE

Page 22: On Fractional PID Controllers a Frequency Domain Approach

IEEE CDC 2002 T W: Fractional Calculus Applications in

Automatic Control and Robotics

Conclusions

■ Advantages of fractional PID– Better for fractional systems– Similar simplicity and compactness– More general structure: added flexibility

■ Problems– Realizations

■ Work in progress– Lab prototypes of fractional operators, analog and

digital, working fine.