Experimental Application of Robust and Converse Dynamic Control for Rotary Flexible Joint Manipulator System

Performance evaluation of trajectory tracking for a rotary flexible joint system is demonstrated in this paper. The robust and converse dynamic (RCD) technique is proposed and implemented for this evaluation. This control methodology is of the left inversion type, i.e., the control inputs are obtained by means of plant output error feedback. RCD control encompasses the baseline inverse (BI) control and sliding mode control-based discontinuous control element. The baseline inverse controller enforces the prescribed servo (virtual) constraints that represent the control objectives. The control objectives of the baseline inverse controller are enclosed in the form of servo (virtual) constraints which are inverted using Moore–Penrose Generalized Inverse (MPGI) to solve for the baseline control law. To boost the robust attributes against parametric uncertainties and disturbances, a discontinuous control function is augmented with baseline controller such that semiglobal practical stability is guaranteed in the sense of Lyapunov. To exhibit the effectiveness of RCD control in terms of tracking performance, computer simulations are conducted in Simulink/Matlab environment. Furthermore, the practical implementation is also investigated through a real-time experiment on Quanser’s rotary flexible joint manipulator system. The experimental results obtained by RCD are compared to the conventional sliding mode and fractional-order control techniques.

Controlling a Direct Matrix Frequency Converter of Secondary Power Supply Sources for Autonomous Objects

A version of using "sliding modes" in performing discontinuous control of dynamic objects for matrix frequency converters (MFC) as part of an on-board aircraft network is proposed. Unlike the way used in the existing MFC control algorithms, the sinusoidal voltages available in the primary network are processed according to the proposed modernized technology of "sliding modes". The level of discontinuous voltages is selected from the condition of minimum deviations from the target, which has a favorable effect on the spectrum of output voltages. On the selected time interval, the input primary network phase voltages and the specified output network phase voltages are sampled. A positive minimum difference between the primary network phase voltage closest to its desired value and the specified secondary network phase voltage is produced. This difference acts as a positive discontinuous control. A negative difference acts as a negative discontinuous control. Over the calculated interval, the average deviation from the specified phase voltage is zero. Owing to this feature, the smallest distortions in the MFC output voltage spectrum are obtained at arbitrary loads and evolutions of the primary network voltage frequency and amplitude. Versions of three-phase and six-phase primary sources are considered. The effectiveness of the proposed version of using "sliding modes" has been confirmed by simulation.

A new approach to persistence and periodicity of logistic systems with jumps

<abstract><p>This paper considers a class of logistic type differential system with jumps. Based on discontinuous control theory, a new approach is developed to guarantee the persistence and existence of a unique globally attractive positive periodic solution. The development results of this paper emphasize the effects of jumps on system, which are different from the existing ones in the literature. Two examples and their simulations are given to illustrate the effectiveness of the proposed results.</p></abstract>