Unfolding the fold-Hopf bifurcation in piecewise linear continuous differential systems with symmetry

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Abstract

Three-dimensional symmetric piecewise linear differential systems near the conditions corresponding to the fold-Hopf bifurcation for smooth systems are considered. By introducing one small parameter, we study the bifurcation of limit cycles in passing through its critical value, when the three eigenvalues of the linear part at the origin are at the imaginary axis of the complex plane.

The simultaneous bifurcation of three limit cycles is proved. Conditions for stability of these limit cycles are provided, and analytical expressions for their period and amplitude are obtained.

Finally, we apply the achieved theoretical results to a generalized version of Chua’s circuit, showing that the fold-Hopf bifurcation takes place for a certain range of parameters.

Highlights

► Continuous 3D symmetric piecewise linear differential systems are considered. ► One-parameter fold-Hopf bifurcation unfoldings are studied. ► The critical system exhibits a bounded set foliated by periodic orbits. ► From this set, the simultaneous bifurcation of three limit cycles is proved. ► Such fold-Hopf bifurcation is detected in a generalized version of Chua’s circuit.

Section snippets

Introduction and preliminary results

The study of limit cycles of a differential system is, after the analysis of equilibrium solutions, one of the most important problems in the qualitative analysis of dynamical systems. Several tools from bifurcation theory are available in the case of smooth systems in order to guarantee the bifurcation and existence of limit cycles, see [1], [2], [3]. The situation is worse in the case of piecewise smooth systems, see [4], so that new results concerning this class of differential non-smooth

Statement of main results

Our first result concerns the possible bifurcation of symmetrical periodic orbits using the three zones. We introduce a new parameter δ=dtω2, which characterizes the criticality of the bifurcation, in a similar way to what happens in the cases considered in [11], [12].

Theorem 3

Let us consider system (1)(2) under conditions (4)where it is assumed ρ0 and δ=dtω20 and fixed. For ε=0the system (1)(2) undergoes a tri-zonal limit cycle bifurcation, that is, from the configuration of periodic orbits that

Realization in a generalized Chua’s circuit

In this section we consider the generalized version of Chua’s circuit that appears in Fig. 6(a), where a negative resistance device RN has been introduced with respect to the standard model (see for example [20]). To obtain more information about negative resistance devices, see [21].

The state equations of the circuit of Fig. 6 are (see [22]) dv1dτ=1C1[G(v2v1)f(v1)],dv2dτ=1C2[G(v1v2)+i3],di3dτ=1L(v2+RNi3), where v1 and v2 are the voltages across the capacitors C1 and C2, i3 is the current

Proof of the main results

We start by giving the proof of Proposition 2.

Proof of Proposition 2

From the definition of system (1)–(2) under conditions (4) in the central zone, it is direct to assure that the unique equilibrium point for ε0 and |x|<1 is the origin.

From the third component of equations of system (1)–(2), in the zone x>1, the x-coordinate of the equilibrium point for ε0 is equal to xε+=1+εd(ρ2ε2+ω2). If dε<0 then xε+<1 and the equilibrium point is not a real equilibrium but it is a virtual one. The same is true for the zone x<1

Acknowledgments

Authors are partially supported by the Ministerio de Ciencia y Tecnología, Plan Nacional I+D+I, in the frame of projects MTM2009-07849, MTM2010-20907, MTM2012-31821, and by the Consejería de Educación y Ciencia de la Junta de Andalucía under grants TIC-0130 and P08-FQM-03770.

References (24)

  • V. Carmona et al.

    Limit cycle bifurcation in 3D continuous piecewise linear systems with two zones. Application to Chua’s circuit

    Internat. J. Bifur. Chaos

    (2005)
  • E. Freire et al.

    The focus-center-limit cycle bifurcation in symmetric 3D piecewise linear systems

    SIAM J. Appl. Math.

    (2005)
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