DSP-Based Implementation of Fuzzy Output Tracking Control for a Boost Converter

The design and the implementation of a fuzzy output tracking control applied to a boost converter that operates in large-signal domain are presented. Unlike conventional fuzzy controller design which addresses only small-signal system control and stability, the proposed controller ensures good tracking performances and overall large-signal stability of the system over the whole operating space. This is thanks to: i) The high prediction accuracy of the Takagi-Sugeno fuzzy approximator (TSFA) with twelve affine functions; ii) the possibility to automatically derive the corresponding small-signal model under a wide range of operating conditions; iii) the advantage of integral controllers; and iv) the LMI approach to carry out the overall large-signal stability. After introducing an added integral state of the output tracking error, the resulting augmented system is represented into a Takagi-Sugeno fuzzy model (TSFM). Parallel distributed compensation (PDC) concept is applied to design the state-feedback based control law whereby the control gains are off-line pre-solved by the mean of the linear quadratic regulator (LQR) technique. Sufficient stability conditions are expressed in terms of LMIs. Experimental results using dSPACE DS1104 and a boost converter for different operating conditions, both in tracking and regulation mode; illustrate the efficiency, the robustness and the flexibility of the proposed approach relatively to a classical PID controller.