@article {IOPORT.05955618,
    author       = {Li, Qin},
    title        = {Discussion on: ``Saturated control of chained nonholonomic systems".},
    year         = {2011},
    journal      = {European Journal of Control},
    volume       = {17},
    number       = {2},
    issn         = {0947-3580},
    pages        = {180-182},
    publisher    = {The European Union Control Association; Lavoisier, Cachan},
    abstract     = {Summary: The paper by Yuan and Qu presents a novel switching control law for the global stabilization of nonholonomic systems in the chained form with bounded inputs. The constraints on the controls $u_1$ and $u_2$ are explicitly addressed in the control design phase. It is proved in the paper that for any given positive real number $\rho$ the controller can be tuned to force the state of the system $x\in\bbfR^n$, with an arbitrary initial value, into the ultimate region ${\cal D}_0:=\{x\in\bbfR^n:\|x\|\le \rho\}$ in finite time. The key idea is to set the control $u_1$ for $x_1$ (the first component of the state $x)$ piecewise constant so that the rest of the system becomes a chain of integrators, to which the control design techniques developed in [3,4] can be applied. Compared with the previous work [1], which relies on the nonlinear coordinate transform called $\sigma$-process, the controller proposed in the paper does not have the numerical problem when $x_1$ is very close to the zero and subject to measurement noises (see [2]). In this discussion, we provide a modification of the approach which is primarily aimed at shortening the time required to fulfill the control goal.},
    identifier   = {05955618},
}