For the design, implementation and testing of control systems increasingly hardware-in-the-loop (HIL) simulation is required, where parts of the control loop components are real hardware and parts are simulated. Usual...
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For the design, implementation and testing of control systems increasingly hardware-in-the-loop (HIL) simulation is required, where parts of the control loop components are real hardware and parts are simulated. Usually, the process is simulated because it is not available (simultaneous engineering), or experiments with the real process are too costly or require too much time. The sensors and actuators may be simulated or real and the controller is real hardware and software. The real-time requirements for the simulation depends on the time scale of the process and the simulated components. The contribution gives first an overview of the various kinds of real-time and HIL simulation. Then, two cases are considered. First the HIL simulation for relatively slow processes, like in basic industries or heating systems. Here, the simulation-speed may be limited either by the complexity of the processes or by the real controller hardware. Then, the HIL simulation of combustion engines both with transputers and digital signal processors is shown in detail. The required models for 6- and 8-cylinder diesel engines are described, including fuel injection and burning, pressure development, torque generation at the crankshaft, exhaust turbocharger dynamics and the vehicle dynamics. The HIL-simulator test bench consísts of a real-time computer system, sensor-interface, actuator interface, real injection pumps and the real control unit. Comparisons of real-time simulation with measurements on real diesel engines and trucks are shown. The goal of the HIL system is to develop new control algorithms and to investigate the effect of faults in sensors and actuators and the engine itself.
In automotive technology, the behaviour of SI-combustion engines is often characterised by the dependency of the engine torque on the engine speed and the throttle angle. Especially for control and simulation purposes...
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In automotive technology, the behaviour of SI-combustion engines is often characterised by the dependency of the engine torque on the engine speed and the throttle angle. Especially for control and simulation purposes it is important to provide an easy possibility to extract a formal description of an engine characteristic map from data measured on an engine test stand. This paper describes a way to replace the conventionally used look-up-tables by neural network or fuzzy logic representations and to adapt them on-line to measured signals. In addition to that, a neuro-fuzzy approach is discussed as well.
The problem of robust controller design is addressed for a single-input single-output plant with a single uncertain parameter. Given one controller that stabilizes the nominal plant, the Youla-Kucera parametrization o...
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Motivated by the pole placement design techniques, linear polynomial (or diophantine) equations have become a popular design tool of control engineers. The paper presents the theory, properties, and computational algo...
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Motivated by the pole placement design techniques, linear polynomial (or diophantine) equations have become a popular design tool of control engineers. The paper presents the theory, properties, and computational algorithms for the equation ax + by = c in a tutorial manner. Recent results are presented on the parametrization of limited degreee solutions, of relatively prime solutions, and of solutions x, y such that y/x is proper rational. Parametric and non-parametric computational algorithms are discussed in detail. Motivées par les méthodes de placement des pôles, les équations linéaires polynomiales (ou Diophantine) sont de venue un outil mathématique polulaire parmi les automaticiens. Cette communication a pour but de présenter, d'une manière synoptique, la théorie et le calcul numérique liés à l' équation ax + by = c. Plusieurs résultats récents sont présentés, sur la paramétrisation des solutions x, y de degré borné, sur les solutions x, y premières entre elles et sur les solutions telles que le rapport y/x est rationnel et propre. Plusieurs méthodes de résolution de cette équation, paramétriques ou non, sont discutées en détail.
Two algorithms are proposed for evaluating the rank of an arbitrary polynomial matrix. They rely upon constant matrix rank evaluations and therefore are more reliable than already existing elementary polynomial operat...
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Two algorithms are proposed for evaluating the rank of an arbitrary polynomial matrix. They rely upon constant matrix rank evaluations and therefore are more reliable than already existing elementary polynomial operations techniques. Some applications are mentioned, such as polynomial null-space extraction or conditions of existence of solutions to matrix polynomial equations arising in control problems. Deux algorithmes sont proposés pour évaluer le rang d'une matrice polynomiale quelconque. Ils sont basés sur des évaluations de rangs de matrices constantes et sont donc plus fiables que les techniques déjà existantes d'opérations polynomiales élémentaires. Quelques applications sont mentionnées, comme l'extraction du noyau polynomial ou des conditions d'existence de solutions aux équations polynomiales matricielles provenant de problèmes de commande.
Predictive control algorithms are promising also in the case of nonlinear systems. Long-range predictive control algorithms are derived here for the nonlinear Hammerstein model. A quadratic cost function is minimized,...
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Predictive control algorithms are promising also in the case of nonlinear systems. Long-range predictive control algorithms are derived here for the nonlinear Hammerstein model. A quadratic cost function is minimized, which considers the quadratic deviation of the reference signal and the output signal predicted in a future horizon and punishes also the squares of the control increments. The predictive incremental form of the Hammerstein model is used to predict the output signal. Suboptimal versions of the control algorithm are given with different assumptions for the control signal during the control horizon. Some properties of these algorithms are shown through simulation examples. Behaviour of long-range predictive control algorithms is compared with the performance of one-step-ahead predictive control algorithms.
In this paper, model and signal-based methods for supervision of suspension elements of a car are presented. A model-based approach using parameter estimation is used to determine the current parameters of a vehicle s...
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In this paper, model and signal-based methods for supervision of suspension elements of a car are presented. A model-based approach using parameter estimation is used to determine the current parameters of a vehicle suspension. Exploiting the analytical redundancy, different faults, like weak dampers or sensor faults, can be distinguished. For fault detection the use of parity equations is shown. In addition, a signal-based approach is presented which makes a detection of tire pressure loss possible. All presented results were drawn from a test rig or from a driving car.
Knowledge-based fault detection and diagnosis is described from the analytic and heuristic symptom generation to diagnostic reasoning. The extension of the knowledge-based approach by adaptive neural networks allows u...
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Knowledge-based fault detection and diagnosis is described from the analytic and heuristic symptom generation to diagnostic reasoning. The extension of the knowledge-based approach by adaptive neural networks allows us to tune the knowledge base in order to investigate undetermined parameters just as membership functions, relevance weights of antecedents and priority factors of rules. An overview of design methodologies of neuro-fuzzy systems is provided with a special focus on a hybrid neuro-fuzzy network with a neural logical operator. Finally, an application of the neuro-fuzzy system to the on-line monitoring of air pressure in vehicle wheels is described. (C) 1997 Elsevier Science B.V.
Due to the rising consciousness of safety aspects, the supervision of vehicles' tyre pressures is a major aspect of improved active car safety. Therefore, in this paper a method for monitoring the tyre pressures i...
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Due to the rising consciousness of safety aspects, the supervision of vehicles' tyre pressures is a major aspect of improved active car safety. Therefore, in this paper a method for monitoring the tyre pressures is presented, using body acceleration signals. Analyzing the frequency spectrum of the virtual transfer function between the body acceleration at the front and rear wheel on one side of the vehicle, characteristic features are generated. Thereby, external interferences on the spectrum and their influences on the symptoms are discussed. To quantify the tyre pressure, a neuro-fuzzy classification of the characteristics is applied. Copyright (C) 1997 Elsevier Science Ltd.
As individual and commercial traffic flow on roads and highways grows enormously, the number of accidents increases as well. Therefore, modern vehicle research is focused on improving driving comfort as well as passen...
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As individual and commercial traffic flow on roads and highways grows enormously, the number of accidents increases as well. Therefore, modern vehicle research is focused on improving driving comfort as well as passengers' safety. Aiming at that, recent advances in controlengineering and modern computer technology enable the engineer to design special control and supervision systems to support the driver. As an example, this contribution presents two possible solutions. An Adaptive Cruise control system assists the driver in highway traffic, whereas a vehicle-supervision method is applied to detect critical driving situations and sensor faults. Copyright (C) 1997 Elsevier Science Ltd.
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