ABSTRACT
This paper presents the application of an linear quadratic gaussian (LQG) control strategy for concrete caisson deployment for marine structures. Currently these maneuvers are carried out manually with the risk that this entails. Control systems for these operations with classical regulators have begun to be implemented. They try to reduce risks, but they still need to be optimized due to the complexity of the dynamics involved during the sinking process and the contact with the sea bed. A linear approximation of the dynamic model of the caisson is obtained and an LQG control strategy is implemented based on the Kalman filter (KF). The results of the proposed LQG control strategy are compared to the ones given by a classic controller. It is noted that the proposed system is positioned with greater precision and accuracy, as shown in the different simulations and in the Monte Carlo study. Furthermore, the control efforts are less than with classical regulators. For all the reasons cited above, it is concluded that there is a clear improvement in performance with the control system proposed.
ABSTRACT
This paper presents a new handle for instruments used in laparoscopic surgery. This new handle has been designed to provide the best ergonomic and usability features required in this kind of surgical interventions. The main novelty of this handle is that the opening and closing motion of the end-effector is operated with the thumb using a lever located on the top of the handle. This enables the surgeon to reach the patient's organs without adopting extremely awkward postures. In order to demonstrate its advantages, the handle has been tested and compared with another commercial handle in terms of efficiency, effectiveness, and satisfaction. To this end, volunteers have been selected for participation in the experimental evaluation, which comprised two types of surveys: objective and subjective. Electromyography and goniometric studies provide objective parameters for evaluation. Questionnaires are used for the subjective assessment. Outstanding results include the lower level of pain reported by the individuals working with the new handle, as well as the reduction in the hyperflexion of the wrist. Compared with the conventional handle, electromyography reveals that no muscle load is increased when working with the new handle. The results of the subjective survey show that volunteers expressed a significant preference for the new handle, demonstrating an improvement in the ergonomic characteristics.
