1,891 research outputs found
Control of a non-isothermal continuous stirred tank reactor by a feedback–feedforward structure using type-2 fuzzy logic controllers
A control system that uses type-2 fuzzy logic controllers (FLC) is proposed for the control of a
non-isothermal continuous stirred tank reactor (CSTR), where a first order irreversible
reaction occurs and that is characterized by the presence of bifurcations. Bifurcations due
to parameter variations can bring the reactor to instability or create new working conditions
which although stable are unacceptable. An extensive analysis of the uncontrolled CSTR
dynamics was carried out and used for the choice of the control configuration and the development
of controllers. In addition to a feedback controller, the introduction of a feedforward
control loop was required to maintain effective control in the presence of disturbances.
Simulation results confirmed the effectiveness and the robustness of the type-2 FLC which
outperforms its type-1 counterpart particularly when system uncertainties are present
Anticipation and Risk – From the inverse problem to reverse computation
Abstract. Risk assessment is relevant only if it has predictive relevance. In this sense, the anticipatory perspective has yet to contribute to more adequate predictions. For purely physics-based phenomena, predictions are as good as the science describing such phenomena. For the dynamics of the living, the physics of the matter making up the living is only a partial description of their change over time. The space of possibilities is the missing component, complementary to physics and its associated predictions based on probabilistic methods. The inverse modeling problem, and moreover the reverse computation model guide anticipatory-based predictive methodologies. An experimental setting for the quantification of anticipation is advanced and structural measurement is suggested as a possible mathematics for anticipation-based risk assessment
Fuzzy logic control of a two degree of freedom parallel robot
Parallel robots differ greatly from their serial counterparts in terms of performance and mechanical ability. Serial robots are open chained mechanisms since each link is connected to an adjacent one and each joint is actuated, while parallel robots implement a closed chained structure. This type of structure consists of having the endpoint of each kinematic chain connected to one another, hence called the common point. There can be a multitude of kinematic chains, but each chain utilizes only one actuator located near the base of the system to perform the desired operation
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