Because of high accuracy, excellent repeatability and low pressure drop, turbine flowmeter is widely used in industry to measure gas or liquid flow. However, the disadvantage in linearity restricts its application. A ...
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With the advantage of low initial investment and high running efficiency, experimental facility for flow measurement using master meter method has a broad application. Meanwhile, the sonic nozzle based on the reliable...
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This paper is concerned with Markovian jump systems subject to incomplete knowledge of transition probabilities and actuator saturation. The system under consideration is more general, which covers the systems with co...
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Abstract The number of model-based approaches in modern engine control units (ECUs) increases permanently with the increase of engine complexity. Therefore the efficient storage and the fast computation of these model...
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Abstract The number of model-based approaches in modern engine control units (ECUs) increases permanently with the increase of engine complexity. Therefore the efficient storage and the fast computation of these models is a challenging task. Due to their fast computation properties most ECUs utilize 2-dimensional grid map structures. Higher dimensional relations need then to be mapped with nested structures of several 2-dimensional grid maps. The determination of suited structures is a time-consuming task and the number of utilized 2-dimensional grid maps may be large for higher dimensional relations. Therefore in the following a grid map structure, a LOLIMOT structure, a Kernel method and an adaptive polynomial approach are compared with respect to model accuracy, computation time and required memory. Conclusions about the implementation on state of the art ECUs are given. As model output the NO x emissions of a DTH Z19 Opel CR-Diesel engine with VGT-turbocharger and exhaust gas recirculation are regarded. Model structures are presented for a global model approach comprising the engine operation point as input, and for a global-local approach predicting the output by weighting local models.
In this paper, a continuous, time varying adaptive controller is developed for an underactuated quadrotor unmanned aerial vehicle (UAV). The vehicle's dynamic model is subject to uncertainties associated with mass...
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Abstract Due to more and more stringent emission regulations the optimisation of transient engine operation becomes necessary for future Diesel engine developments. Exemplary for the transient operation a step in acce...
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Abstract Due to more and more stringent emission regulations the optimisation of transient engine operation becomes necessary for future Diesel engine developments. Exemplary for the transient operation a step in acceleration pedal is investigated and optimised with respect to the engine emissions. This gives insights about the emission formation at transient driving and a benchmark for the design of open and closed-loop controls. A model structure to simulate the engine emissions and the engine torque is presented. It consists of a dynamical mean value air path model and a stationary combustion model. Thus the relevant outputs NO x , soot and torque are simulated with respect to the engine actuators. For optimisation the calibrated emission values for steady state are regarded. The actuators of the air path and the crank angle of the main injection are optimised such that the emissions follow a desired trajectory. The results are compared to a non-optimised step in acceleration and to a nonlinear closed loop control of the air path.
Based on deep investigation to the static and dynamic characteristics of Hammerstein and Wiener model structures, this paper proposes an included angle based nonlinearity measure for SISO Hammerstein-like systems. The...
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Earlier investigations show that the results of hazard identification (HAZID) and analysis (e.g. HAZOP or FMEA) can effectively be used for knowledge-based diagnosis of complex process systems in their steady-state op...
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A novel structure identification procedure for discrete event systems described by Petri nets are proposed in this paper for model-based diagnostic purposes that utilize the notions and tools of process mining. The id...
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ISBN:
(纸本)9780889868632
A novel structure identification procedure for discrete event systems described by Petri nets are proposed in this paper for model-based diagnostic purposes that utilize the notions and tools of process mining. The identification of the structurally different discrete event system models describing a system in its normal and/or faulty modes was used for model-based isolation of the considered faulty modes. From the available process mining techniques that allow for the automatic construction of process models in Petri net form based on event logs, the genetic algorithm-based structure identification procedure has been found to be most capable of identifying the characteristic structural elements of the faulty models. The proposed procedures are illustrated on a simple example of an operated parking gate automaton with two faulty modes.
Hammerstein models are popular in describing nonlinear chemical processes. The general control strategy for Hammerstein models is the nonlinearity inversion method, which is unfortunately inapplicable to Hammerstein s...
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