In this paper, we propose a control system design to satisfy multiconstraints in the time and frequency domains using the framework of continuous time deadbeat control. At first, two conditions are introduced for the free parameter of H∞ suboptimal controllers corresponding to an interpolation condition for the deadbeat control and a norm constraint for the H∞, control. The parametrization of the controllers satisfying the two conditions simultaneously is given by restricting the modified free parameters of H∞, controllers to commensurate time delay functions. The other constraints of approximated L1 norm or L2 norm are also reduced to convex finite-dimensional problems and these mixed problems are solved numerically.
This paper proposes a partial shape matching method for functionally approximated shapes. The proposed method consists of a feature extraction procedure and a correspondence detection procedure among convexities. In the feature extraction, we introduced a wedge-shaped tiny figure, called wedge wave, as a basis of convexities. The DP (Dynamic Programming) matching has been applied to the correspondence detection among extracted convexities using a method to reduce the amount of computation. The proposed method has been applied to several figures for evaluation. The results showed that our method could recognize partial similarity without the restriction of location, size, and orientation. It has been confirmed that, by utilizing the information of an approximating function, a large amount of computation in feature extraction can be reduced.
One of fundamental problems in design of construction machines is to make a practical model which represents the relation between input and output signals. For an example, an excellent model is useful for designing superior controllers which result in automation and simplification of operations. However, it is difficult to make a detailed mathematical model for construction machines because of nonlinear characteristics of hydraulic actuators and its complicated mechanical structures. In this paper, a fuzzy model for an aerial working platform is described. The fuzzy model in each driving axis is based on fuzzy rules and approximated dynamic models which are measured in advance under different operating conditions. The fuzzy rules represent not only the static nonlinear characteristics of actuator but also the effect of the approximated dynamic models on the output under the different operating conditions, and are automatically adjusted by a tuning law so that modeling error decreases. The effectiveness of the proposed fuzzy model is demonstrated by experimental results.
This paper proposes a design method of a quadratically stabilizing state feedback controller with a time-varying gain for a class of discrete-time uncertain systems. Our aim is to improve the closed-loop performance by using the time-varying gain as a tuning parameter. It is required to achieve the ideal responses that we solve an optimization problem and estimate the plant parameter within one sample time. Since the implementation is considered to be almost impossible, a restricted method is introduced which does not always yield the optimal solution. However, the method shows acceptable results in the numerical simulations.
Genetic Algorithm is applied to a scheduling problem in the plastic injection molding process. The problem is simplified by combinig the jobs with the same die. Total lateness to the due date is taken as an evaluation function and rather sufficient solution is obtained by GA. Moreover, a modified decoding procedure is proposed to optimize the second objective, without decreasing the original evaluation value. Simulation with real data in an industry shows an effectiveness of the proposed method.
In this paper, we consider an internal model control structure for discrete event systems based on max-algebra. Since a simple prediction is used in the conventional method, the performance often shows undesirable one. Therefore, we propose a new prediction strategy with a filter and a new control law using states of the controlled plant in order to overcome the above mentioned drawbacks. Finally, we illustrate simulation results in order to make sure of the effectiveness of the proposed method.
Needless to say, how to conserve and, desirably, improve water quality of Lake Biwa is an extremely important problem to be solved. This paper is concerned with reduction of pollutant load discharged from paddy fields. In Shiga Prefecture around Lake Biwa, the rice crop is dominant in the agriculture, and the water discharged from each paddy field flows into Lake Biwa through drainage canals. Then from the viewpoint that the outlet of each paddy field is a source of pollution, at a paddy field of 30 ares, the authors examined in detail about the input/output of water and the outflow of nutrients for three years. Based upon the results of the examination, this paper develops a model for describing input/output of water at a paddy field, and simulates and evaluates some methods for reducing outflow discharged from a paddy field.