Selecting a proper initial input for Iterative Learning Control (ILC) algorithms has been shown to offer faster learning speed compared to the same theories if a system starts from blind. Iterative Learning Control is...Selecting a proper initial input for Iterative Learning Control (ILC) algorithms has been shown to offer faster learning speed compared to the same theories if a system starts from blind. Iterative Learning Control is a control technique that uses previous successive projections to update the following execution/trial input such that a reference is followed to a high precision. In ILC, convergence of the error is generally highly dependent on the initial choice of input applied to the plant, thus a good choice of initial start would make learning faster and as a consequence the error tends to zero faster as well. Here in this paper, an upper limit to the initial choice construction for the input signal for trial 1 is set such that the system would not tend to respond aggressively due to the uncertainty that lies in high frequencies. The provided limit is found in term of singular values and simulation results obtained illustrate the theory behind.展开更多
In this study, the characteristics of Graphite/Epoxy Composites (GECs) are evaluated from mechanical perspectives. Different weight percentages of graphite were used (0 - 7 wt%) for tensile and hardness experiments. T...In this study, the characteristics of Graphite/Epoxy Composites (GECs) are evaluated from mechanical perspectives. Different weight percentages of graphite were used (0 - 7 wt%) for tensile and hardness experiments. Then the findings were discussed to ascertain the optimum mixing ratio of the graphite with the epoxy. The primary finding of this study is that the graphite weight fraction has a substantial impact on the composites’ mechanical performance. At a low percentage (1 wt%), the graphite has little influence on the tensile behaviour. An intermediate weight percentage of the graphite is considered optimum for mechanical performance in the epoxy composites as it slightly reduces the tensile properties and significantly improves the hardness. Micrographs of the fractured surface of specimens showed many signs that clearly explained why fractures had occurred. For instance, when graphite/epoxy composite contained a low proportion of graphite, the cleavage failure was very easy to observe because there was no sign of aggregation or the detachment of fillers.展开更多
文摘Selecting a proper initial input for Iterative Learning Control (ILC) algorithms has been shown to offer faster learning speed compared to the same theories if a system starts from blind. Iterative Learning Control is a control technique that uses previous successive projections to update the following execution/trial input such that a reference is followed to a high precision. In ILC, convergence of the error is generally highly dependent on the initial choice of input applied to the plant, thus a good choice of initial start would make learning faster and as a consequence the error tends to zero faster as well. Here in this paper, an upper limit to the initial choice construction for the input signal for trial 1 is set such that the system would not tend to respond aggressively due to the uncertainty that lies in high frequencies. The provided limit is found in term of singular values and simulation results obtained illustrate the theory behind.
文摘In this study, the characteristics of Graphite/Epoxy Composites (GECs) are evaluated from mechanical perspectives. Different weight percentages of graphite were used (0 - 7 wt%) for tensile and hardness experiments. Then the findings were discussed to ascertain the optimum mixing ratio of the graphite with the epoxy. The primary finding of this study is that the graphite weight fraction has a substantial impact on the composites’ mechanical performance. At a low percentage (1 wt%), the graphite has little influence on the tensile behaviour. An intermediate weight percentage of the graphite is considered optimum for mechanical performance in the epoxy composites as it slightly reduces the tensile properties and significantly improves the hardness. Micrographs of the fractured surface of specimens showed many signs that clearly explained why fractures had occurred. For instance, when graphite/epoxy composite contained a low proportion of graphite, the cleavage failure was very easy to observe because there was no sign of aggregation or the detachment of fillers.
