The distinguishability and identifiability of biological network models are key properties influencing the reliability of structural and parametric identification of such models. Recently, several new results have bee...
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The distinguishability and identifiability of biological network models are key properties influencing the reliability of structural and parametric identification of such models. Recently, several new results have been published about dynamically equivalent and linearly conjugate reaction networks. In this paper, the notion and importance of dynamical equivalence and linear conjugacy of biochemical network models obeying the mass action law is shown. For this, new concepts in the form of core complexes and core reactions for linearly conjugate networks are introduced. Two examples illustrate the developed computation methods.
This paper presents fault detection, fault diagnosis, the fault-tolerant control of an electro-hydraulic servo axes with a duplex-valve-system. The fault detection is based on parity equations and is load independent....
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This paper tackles the robust stabilization problem for the plant family described by the transfer function set P ( s, δ , δ ) whose coefficients of the denominator and the numerator polynomials are affine in a real...
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This paper tackles the robust stabilization problem for the plant family described by the transfer function set P ( s, δ , δ ) whose coefficients of the denominator and the numerator polynomials are affine in a real uncertain parameter vector δ satisfying the norm constraint || δ || p ≤ δ for p ≥ 1. It is shown that there exists a fixed controller robustly stabilizing all the members of P ( s, δ , δ ) if and only if its every member plant is free of unstable pole-zero cancelation. The optimal robust stabilizer is characterized in terms of a three dimensional frequency dependent Hahn-Banach minimizer. Classes of P ( s, δ , δ ) are characterized using Nevanlinna-Pick interpolation theory. For these classes optimal robust stabilizers can be obtained in closed forms using ℋ ∞ -optimization technique.
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 ch...
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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 ...
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For a class of uncertain multi-input-multi-output (MIMO) discrete-time nonlinear systems with strong coupling and unstable zero-dynamics, an adaptive generalized predictive decoupling switching control method based on...
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For a class of uncertain multi-input-multi-output (MIMO) discrete-time nonlinear systems with strong coupling and unstable zero-dynamics, an adaptive generalized predictive decoupling switching control method based on unmodeled dynamic compensation is proposed. It is only required that the higher order nonlinear terms of the system to satisfy a linear growth condition, rather than the global boundedness condition widely used. The analysis of stability and convergence of the adaptive control method are performed. Moreover, in designing the nonlinear generalized predictive decoupling controller, we combine the adaptive-network-based fuzzy inference system (ANFIS) training with the "one-toone mapping" technique to adaptively estimate the unmodeled dynamics, so that the universal approximation property of ANFIS can be guaranteed. Finally, simulation results demonstrate the superiority of the proposed method and validate the theoretical analysis.
Abstract This paper presents fault detection, fault diagnosis, the fault-tolerant control of an electro-hydraulic servo axes with a duplex-valve-system. The fault detection is based on parity equations and is load ind...
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Abstract This paper presents fault detection, fault diagnosis, the fault-tolerant control of an electro-hydraulic servo axes with a duplex-valve-system. The fault detection is based on parity equations and is load independent. The semi-physical models allow the detection of even small faults in the hydraulic system. The fault diagnosis used at the testbed is based on fuzzy-logic. In order to tolerate a faulty hydraulic proportional valve, a duplex-valve-system built up with standard proportional valves is applied. The fault management module allows the supervision of the hydraulic servo axes and decides on the reconfiguration of the control-loop. An Internal Model control (IMC)-tracking control structure for bumpless transfer between controllers is presented. Experimental results show the industrial applicability of the approach.
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.
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.
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 processsystems in their steady-state op...
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