Digital version of Fractional-Order PID Controller (DFOC) of the form:
C(s) = K + Ti/s^m + Td*s^d for given sampling period Ts [sec].

For more details and help write:
>> help DFOC

It is based on:
http://www.mathworks.com/matlabcentral/fileexchange/3672
http://www.mathworks.com/matlabcentral/fileexchange/3673
http://www.mathworks.com/matlabcentral/fileexchange/31358

See also books:

[1] Ivo Petras, Fractional-Order Nonlinear Systems: Modeling, Analysis and Simulation, Springer, Series: Nonlinear Physical Science, 2011, ISBN 978-3-642-18100-9. http://www.springer.com/engineering/control/book/978-3-642-18100-9

[2] Riccardo Caponetto, Giovanni Dongola, Luigi Fortuna and Ivo Petras, Fractional Order Systems: Modeling and Control Applications, World Scientific, Singapore, 2010, ISBN 978-9-814-30419-1. http://www.worldscibooks.com/chaos/7709.html

[3] Ivo Petras, Fractional Derivatives, Fractional Integrals, and Fractional Differential Equations in Matlab, chapter 10, in: Engineering Education and Research Using MATLAB, Ali H. Assi (Ed.), InTech, ISBN 978-953-307-656-0. http://www.intechopen.com/articles/show/title/fractional-derivatives-fractional-integrals-and-fractional-differential-equations-in-matlab