Multiple models are recognised by their abilities to accurately describe nonlinear dynamic behaviours of a wide variety of nonlinear systems with a tractable model in control engineering problems. Multiple models are built by the interpolation of a set of submodels according to a particular aggregation mechanism, with the heterogeneous multiple model being of particular interest. This multiple model is characterized by the use of heterogeneous submodels in the sense that their state spaces are not the same and consequently they can be of various dimensions. Thanks to this feature, the complexity of the submodels can be well adapted to that of the nonlinear system introducing flexibility and generality in the modelling stage. This paper deals with off-line identification of nonlinear systems based on heterogeneous multiple models. Three optimisation criteria (global, local and combined) are investigated to obtain the submodel parameters according to the expected modelling performances. Particular attention is paid to the potential problems encountered in the identification procedure with a special focus on an undesirable phenomenon called the no output tracking effect. The origin of this difficulty is explained and an effective solution is suggested to overcome this problem in the identification task. The abilities of the model are finally illustrated via relevant identification examples showing the effectiveness of the proposed methods.
New methodologies for Fault Tolerant Control (FTC) are proposed in order to compensate actuator faults in nonlinear systems. These approaches are based on the representation of the nonlinear system by a Takagi-Sugeno model. Two control laws are proposed requiring simultaneous estimation of the system states and of the occurring actuator faults. The first approach concerns the stabilization problem in the presence of actuator faults. In the second, the system state is forced to track a reference trajectory even in faulty situation. The control performance depends on the estimation quality; indeed, it is important to accurately and rapidly estimate the states and the faults. This task is then performed with an Adaptive Fast State and Fault Observer (AFSFO) for the first case, and a Proportional-Integral Observer (PIO) in the second. Stability conditions are established with Lyapunov theory and expressed in a Linear Matrix Inequality (LMI) formulation to ease the design of FTC. Furthermore, relaxed stability conditions are given with the use of Polya's theorem. Some simulation examples are given in order to illustrate the proposed approaches.
Coal mining is the dominating industry in the study area of Huainan (Province Anhui, China). As a consequence, subsidence of the surface takes place reaching up to 21 m. It is predicted that nearly 7.700 km2 will be affected until the end of coal mining activity. As a countermeasure, reclamation is done by depositing coal mining waste or fly ash. These substrates are covered with topsoil for agricultural use. The aim of this study is the relationship of the pH value, nutrients supply and water balance and other index between thickness of topsoil, in order to achieve sustainable and economic application of the reclaimed land.
PL
W niniejszej pracy badano wpływ na środowiska przemysłowej Huainan (Prowincja Anhui, Chiny). Wykazano, że na tym obszarze subsydencja powierzchni sięga do 21 m. Oszacowano, że blisko 7700 km2 powierzchni zostanie dotknięte działalnością górniczą, dopóki prace górnicze nie zostaną wstrzymane. Aby zapobiec temu stanowi rzeczy, wykonuje się prace rekultywacyjne polegające na składowaniu odpadów górniczych oraz popiołów lotnych. Tę warstwę pokrywa się warstwą gleby ornej celem umożliwienia na tym terenie wprowadzenia upraw rolnych. Celem niniejszej pracy było ustalenia związku pomiędzy wartością pH value, a dostarczaniem nawozów sztucznych do gleby, jak również określenie bilansu wodnego potrzebnego do wykonania rekultywacji terenu.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.