Feasibility studies of promising stability and gravity /including zero-G/ experiments for manned orbiting missions Final report, 17 Dec. 1964 - 17 Dec. 1965

Feasibility of stability and gravity experiments for manned orbiting mission

Aeronautical engineering, a continuing bibliography with indexes

This bibliography lists 823 reports, articles, and other documents introduced into the NASA scientific and technical information system in November 1984

Absolute stabilization of Lur’e systems by periodically intermittent control

International audienceIn this paper, we design periodically intermittent feedback controllers for Lur'e systems to achieve absolute stabilization. More precisely, our designed periodically intermittent feedback controller is able to cope with any unknown Lur'e-type nonlinearity within a given sector. First, by means of global exponential Lyapunov stability, a set of sufficient stability conditions on the controlled Lur'e system is derived. Subsequently, we give the controller design algorithm in terms of the necessary and sufficient conditions to the stability criteria. By using the LMI Control Toolbox in Matlab, it is easy to compute the control parameters, including the feedback gain matrix, the control period and the control width, involved in the stability criteria. A numerical example considering a Chua's oscillator under periodically intermittent feedback control is presented to illustrate the validity of our obtained theoretical results. Finally, further discussions close the paper along with some possible interesting topics for future research

Practical absolute stabilization of Lur'e systems via periodic event-triggered feedback

International audienceThis paper deals with communication-aware absolute stabilization problems of Lur'e systems using intermittent state information. The full state information is sampled periodically, but transmitted over communication networks to the controller aperiodically according to an event-triggering strategy. The sequence of the event-triggering transmission instants is certainly a subset of that of the time-triggering sampling instants. Hence the time-triggering strategy prevents the event-triggering strategy from the so-called Zeno behavior immediately. We employ the emulation-based approach and divide the controller design procedure into two steps. First, we present a time-triggered controller guaranteeing the global exponential absolute stability for the resulting closed-loop Lur'e system. The obtained sufficient stability conditions involving the state feedback gain matrix and the constant sampling period are derived by means of absolute stability theory. Subsequently, its robustness is analyzed against the control input error induced by the event-triggering mechanism. Under a prescribed periodic event-triggering strategy with a freely selectable parameter, a periodic event-triggered controller is obtained for the Lur'e system to achieve practical exponential absolute stabilization. Finally, linear matrix inequality (LMI) techniques are used to compute all the control parameters