In this paper, we consider semi-global L2 gain analysis for nonlinear systems described as linear systems with self-scheduling parameters. First we show a method to convert linear systems with self-scheduling parameters into linear systems with scheduling parameters based on evaluation of the domain of the self-scheduling parameters. Second, using the tools for linear systems with scheduling parameters, we discuss semi-global L2 gain analysis for the nonlinear systems and propose an approach together with feasible formulas of computation, which provides a solution to the so-called hidden loop problem in gain scheduling. Finally, we show numerical examples.
The authors have proposed the time-state control form and its control strategy to control a class of nonholonomic systems without a drift term, which method is more useful, or has broader applicable class of systems, than the chained form one. In this paper, necessary and sufficient conditions for transformation of a class of nonholonomic systems into the time-state control form are given, and new control strategy for the time-state control form to ensure the (exponential) stabilization of the subsystem by some sort of Lyapunov's discussion is also presented. For each of the topics, simple and illustrative example will be shown.
In this paper, we show a result of practical flight control systems synthesis adopting recently developed gain scheduled control framework. First, we propose a general method to obtain linear parameter varying (LPV) model with norm bounded uncertainties from state space realization data at several operation points. Using the obtained LPV model, we next give a method to design a gain scheduling controller that satisfies multiple control specifications including classical stability margin. Finally, we apply these methods to the flight control systems synthesis of ALFLEX vehicle that requires many practical control specifications.
In this paper, a design method of a static anti-windup compensator which guarantees robust stability subject to saturation nonlinearities and which attenuates a windup phenomena is proposed. Although this design problem has been considered as a non-convex problem in the previous works, we will show that it can be converted into a convex problem and described by linear matrix inequalities. Two numerical examples show the effectiveness of the proposed method.
In this paper, we consider a design problem of robust nonlinear servosystems which can achieve asymptotic tracking for constant reference inputs. The problem setting in this paper is a little bit different from the usual one. We suppose that the reference input will change from r to r* at time t = 0 and that the initial state of the system is located in a neighborhood of the equilibrium corresponding to the reference input r. Under this setting, we consider a design problem of robust nonlinear servosystems : we consider an augment system including the integrator, design a state feedback gain for the augment system using LMI, and give an input r (t) interpolating r and r* so that the state moves the prescribed regions depending r (t) and consequently the output converges to r*.
Mutually coupled plural Neural Networks (N.N.) modules are proposed from the view point of noncooperative game theory. First, new dynamical models, which is called “Quasi-Gradient System”, to search the Nash Equilibrium (NE) points under [0, 1] -interval or nonnegative constraints are proposed. The stability of the proposed searching models is analyzed by the linearization approach. In addition, relations between the Lotka-Volterra's ecological model or the population genetics model and the proposed searching models are indicated. Second, new mutually coupled plural N.N. modules are introduced to realize the proposed searching model for problems with quadratic objective functions. the asymmetric Hopfield type N.N. can be regarded as a special class of the proposed N.N. modules. Last, by simulations for simple problems, the biffurcations in dynamical behavior such as converging to different NE points, cyclic state transition with no NE points and other exceptional cases are shown.