RESUMO
This paper presents a novel strategy for delayed bilateral teleoperation of mobile manipulator robots. The strategy is based on the hypothesis that if the slave robot behaves similarly as the operator would do to the same task, the operator's perception of the system states improves, and therefore the performance of the task is better. The proposed scheme allows controlling in simultaneously the mobile platform and the manipulator robot employing a single master device and maintaining the stability of the system against variable and asymmetric communication time delays. Stability guidelines based on Lyapunov-Krasovskii method are provided for the adjustment of the delayed system. Besides, a new control allocation strategy is proposed founded on the study of human movement in a task of navigation-pick and place. Finally, the performance of the proposal is compared with the standard switched control using a real robotic platform. As a result in practice, the proposed scheme is easier and more intuitive for the operator, besides it allows to reduce significantly the time necessary to complete the task.
RESUMO
This paper proposes a cascade control scheme for delayed bilateral teleoperation of a quadcopter. The strategy transforms a 6D real quadcopter to an easy-to-teleoperate 3D virtual quadcopter. The scheme is formed by a P+d plus PID controller for each dof. The analysis based on Lyapunov theory gets as result the way to set the control parameters depending on the magnitude of the asymmetric time delays (forward and backward delays). This technic aims to reach stability, simplicity and good performance in practice. Besides, experimental tests about delayed bilateral teleoperation of a quadcopter including the proposed control scheme are shown in order to evaluate the system performance.
RESUMO
Statistical analysis, power spectral density, and Lempel Ziv complexity, are used in a multi-parameter approach to analyze four temporal series obtained from the Electrocardiographic and Respiratory Flow signals of 126 patients on weaning trials. In which, 88 patients belong to successful group (SG), and 38 patients belong to failure group (FG), i.e. failed to maintain spontaneous breathing during trial. It was found that mean values of cardiac inter-beat and breath durations give higher values for SG than for FG; Kurtosis coefficient of the spectrum of the rapid shallow breathing index is higher for FG; also Lempel Ziv complexity mean values associated with the respiratory flow signal are bigger for FG. Patients were then classified with a pattern recognition neural network, obtaining 80% of correct classifications (81.6% for FG and 79.5% for SG).