This study developed a systematic decision-making process for water supply capacity expansion using the analytic hierarchy process. The decision-making criteria were categorized into environmental, economic, technical...This study developed a systematic decision-making process for water supply capacity expansion using the analytic hierarchy process. The decision-making criteria were categorized into environmental, economic, technical and socio-cultural aspects. Capacity expansion of three water resources (Kpong, Weija and Teshie plants) of Accra-Tema Metropolitan Area (Ghana) was studied as a test case. The research resulted in the environmental criterion with the highest priority weight (52.4%), followed by the economic (30.6%), technical (11.3%) and socio-cultural criteria (5.8%). The overall analysis ranked the Kpong plant with a score of 36.1% followed by the Weija and Teshie plants with scores 33.8% and 30.2%, respectively.展开更多
This paper is concerned with the robust adaptive fault-tolerant control of a tandem coaxial ducted fan aircraft under system uncertainty, mismatched disturbance, and actuator saturation.For the proposed aircraft, comp...This paper is concerned with the robust adaptive fault-tolerant control of a tandem coaxial ducted fan aircraft under system uncertainty, mismatched disturbance, and actuator saturation.For the proposed aircraft, comprehensive controllability analysis is performed to evaluate the controllability of each state as well as the margin to reject mismatched disturbance without any knowledge of the controller. Mismatched disturbance attenuation is ensured through a structured Hinfinity controller tuned by a non-smooth optimization algorithm. Embedded with the H-infinity controller, an adaptive control law is proposed in order to mitigate matched system uncertainty and actuator fault. Input saturation is also considered by the modified reference model. Numerical simulation of the novel ducted fan aircraft is provided to illustrate the effectiveness of the proposed method. The simulation results reveal that the proposed adaptive controller achieves better transient response and more robust performance than classic Model Reference Adaptive Control（MRAC） method, even with serious actuator saturation.展开更多
文摘This study developed a systematic decision-making process for water supply capacity expansion using the analytic hierarchy process. The decision-making criteria were categorized into environmental, economic, technical and socio-cultural aspects. Capacity expansion of three water resources (Kpong, Weija and Teshie plants) of Accra-Tema Metropolitan Area (Ghana) was studied as a test case. The research resulted in the environmental criterion with the highest priority weight (52.4%), followed by the economic (30.6%), technical (11.3%) and socio-cultural criteria (5.8%). The overall analysis ranked the Kpong plant with a score of 36.1% followed by the Weija and Teshie plants with scores 33.8% and 30.2%, respectively.
文摘This paper is concerned with the robust adaptive fault-tolerant control of a tandem coaxial ducted fan aircraft under system uncertainty, mismatched disturbance, and actuator saturation.For the proposed aircraft, comprehensive controllability analysis is performed to evaluate the controllability of each state as well as the margin to reject mismatched disturbance without any knowledge of the controller. Mismatched disturbance attenuation is ensured through a structured Hinfinity controller tuned by a non-smooth optimization algorithm. Embedded with the H-infinity controller, an adaptive control law is proposed in order to mitigate matched system uncertainty and actuator fault. Input saturation is also considered by the modified reference model. Numerical simulation of the novel ducted fan aircraft is provided to illustrate the effectiveness of the proposed method. The simulation results reveal that the proposed adaptive controller achieves better transient response and more robust performance than classic Model Reference Adaptive Control（MRAC） method, even with serious actuator saturation.
