This paper designs a joint controller/observer framework using a state dependent Riccati equation(SDRE)approach for an active transfemoral prosthesis system.An integral state control technique is utilized to design a ...This paper designs a joint controller/observer framework using a state dependent Riccati equation(SDRE)approach for an active transfemoral prosthesis system.An integral state control technique is utilized to design a tracking controller for a robot/prosthesis system.This framework promises a systematic flexible design using which multiple design specifications such as robustness,state estimation,and control optimality are achieved without the need for model linearization.Performance of the proposed approach is demonstrated through simulation studies,which show improvements versus a robust adaptive impedance controller and an extended Kalman filter-based state estimation method.Numerical results confirm the benefits of our method over the above-mentioned approaches with regard to control optimality and state estimation.展开更多
Objective To assess stresses produced by different obturator prostheses. Methods Three-dimensional finite clement models of unilateral maxillary defects rehabilitated with different obturators were constructed. The di...Objective To assess stresses produced by different obturator prostheses. Methods Three-dimensional finite clement models of unilateral maxillary defects rehabilitated with different obturators were constructed. The different stresses were analyzed by three-dimensional finite element method under different load angle. Results The Von Mises stress values obtained for the remaining tissues adjacent to defect cavity were higher when rehabilitated by inferior hollow obturator in comparison with by superior hollow obturator. The maximum of Von Mises were higher when rehabilitated by resilient hollow obturator than by rigid hollow obturator. It was also observed that in the rigid type stress distribution contours formed in the remaining tissues adjacent to defect cavity, while in resilient hollow obturator prostheses the stress distributed mainly in the prosthesis itself. The oblique load shows the most maximum of Von Mises among all types of obturator prostheses. Conclusions A high lateral wall of an obturator may be more better in preserving the remaining structures than a shorter prosthesis lateral wall. A soft liner may be incorporated to reduce the pain of the residual maxillary structures and mucosa. When load on defect, higher stress would be generated to the residual maxillary structures. The adjustment of occlusual relationship is very important.展开更多
文摘This paper designs a joint controller/observer framework using a state dependent Riccati equation(SDRE)approach for an active transfemoral prosthesis system.An integral state control technique is utilized to design a tracking controller for a robot/prosthesis system.This framework promises a systematic flexible design using which multiple design specifications such as robustness,state estimation,and control optimality are achieved without the need for model linearization.Performance of the proposed approach is demonstrated through simulation studies,which show improvements versus a robust adaptive impedance controller and an extended Kalman filter-based state estimation method.Numerical results confirm the benefits of our method over the above-mentioned approaches with regard to control optimality and state estimation.
文摘Objective To assess stresses produced by different obturator prostheses. Methods Three-dimensional finite clement models of unilateral maxillary defects rehabilitated with different obturators were constructed. The different stresses were analyzed by three-dimensional finite element method under different load angle. Results The Von Mises stress values obtained for the remaining tissues adjacent to defect cavity were higher when rehabilitated by inferior hollow obturator in comparison with by superior hollow obturator. The maximum of Von Mises were higher when rehabilitated by resilient hollow obturator than by rigid hollow obturator. It was also observed that in the rigid type stress distribution contours formed in the remaining tissues adjacent to defect cavity, while in resilient hollow obturator prostheses the stress distributed mainly in the prosthesis itself. The oblique load shows the most maximum of Von Mises among all types of obturator prostheses. Conclusions A high lateral wall of an obturator may be more better in preserving the remaining structures than a shorter prosthesis lateral wall. A soft liner may be incorporated to reduce the pain of the residual maxillary structures and mucosa. When load on defect, higher stress would be generated to the residual maxillary structures. The adjustment of occlusual relationship is very important.
