Enric Fossas Colet

Adaptive Tracking Control of Nonlinear Power Converters

Abstract Tracking control of basic nonlinear power converters is studied for systems with time-varying parameters. The switching control laws accomplish indirect asymptotic sinusoidal voltage tracking. The exposition emphasizes the use of Fourier expansions in solving an ordinary differential equation of the Abel type. In this paper adaptation schemes are studied.

Switching Frequency Regulation in Sliding Mode Control by a Hysteresis Band Controller

Fixing the switching frequency is a key issue in sliding mode control implementations. This paper presents a hysteresis band controller capable of setting a constant value for the steady-state switching frequency of a sliding mode controller in regulation and tracking tasks. The proposed architecture relies on a piecewise linear modeling of the switching function behavior within the hysteresis band, and consists of a discrete-time integral-type controller that modifies the amplitude of the hysteresis band of the comparator in accordance with the error between the desired and the actually measured switching period. For tracking purposes, an additional feedforward action is introduced to compensate the time variation of the switching function derivatives at either sides of the switching hyperplane in the steady state. Stability proofs are provided, and a design criterion for the control parameters to guarantee closed-loop stability is subsequently derived. Numerical simulations and experimental results validate the proposal.

Sliding Mode Controller and Flatness Based Set-Point Generator for a Three Wheeled Narrow Vehicle

Abstract This paper presents a sliding mode controller for a narrow tilting three wheeled vehicle. A dynamic model of eighteenth order is presented for simulation purposes only. Design and analysis are based on a simpler third order model of a bicycle. The validity of this simplification is verified through simulations. Because of the flatness of the bicycle, trajectories given by a presumed driver are redefined to take into account the limits of the vehicle stability. Finally, tilting and speed controllers are designed in the frame of sliding modes. Analytical and simulation results performed in the simpler and complex model respectively validate these designs.

A sliding mode controlled three wheels narrow vehicle for two passengers

This paper reports a sliding mode controlled three wheels narrow vehicle for two passengers. The whole system is a two-input two-output, eight-teen order dynamical system. In a first and simple design, a set of parameters that achieve an acceptable system performance under perturbations could be selected. Results where validated by simulation. However, the performance shown in a wide range of simulations run allows us to expect analytic proofs will be possible.

A sliding mode controlled three wheeled narrow vehicle

This paper presents a sliding mode controller for a narrow tilting three-wheeled vehicle. The vehicle is modelled as a dynamic eighteen-order system with two inputs and two outputs, however, a simple third-order model of a bicycle is considered for design and analysis. The appropriateness of the simpler model for design purposes is verified through simulations. The designed trajectory control considers vehicle stability limits and takes advantage of the bicycle model flatness. Tilting and speed controllers are designed in the sliding mode framework through the analytical development of the bicycle model and simulated in the full eighteen-order system.

An extension of the unity vector control method

In this work, Unity Vector Control is revisited based on the results by V. Utkin and co-workers. The approach here presented extends the one reported by V. Utkin and co-workers so that independent feedback gains may be specified for each input channel. Simulation results illustrate the advantages of the proposed technique for a holonomic model of a two-link manipulator.

Sliding mode control with complementary inputs for a lean-burn IC engine

This paper presents a robust controller for an internal combustion (IC) engine, as a first stage of a project aiming at developing a hybrid light urban vehicle, running with ethanol in lean burn. This work particularly focuses on the design of a sliding mode control for the IC engine of a series hybrid power-train. The controller must allow for speed control and high fuel efficiency. Simulation results are presented and discussed showing the viability and advantages of the employed control strategy.