This article is intended to give control engineers an overview of models and controls of diesel engines. The main emphasis is on the engine's torque generation, including all necessary ancillary devices (turbocharger, injection-system, etc.), pollutant emission and model-based controls. The paper gives a brief introduction of the basic working principles and the salient features of diesel engines and their main differences to Otto (gasoline or spark-ignited) engines are shown. The most important control tasks are then identified and their implications on engine performance are analyzed. An overview of the current state-of-the-art in industrial diesel control applications is given. It also discusses models for the simulation of transient macroscopic effects, and how these models can be simplified to be useful for controller synthesis. Finally. an outlook on possible future control issues and their role in diesel engine evolution is presented.

Control of diesel engines

Adaptive control is now finding its way into the marketplace after many years of effort. This paper reviews some ideas used to design adaptive control systems. It covers early ideas which primarily attempt to compensate for gain variations and more general methods like gain scheduling, model reference adaptive control, and self-tuning regulators. It is shown that adaptive control laws can be obtained using stochastic control theory. Techniques for analyzing adaptive systems are discussed. This covers stability and convergence analysis. Issues of importance for applications like parameterization, tuning, and tracking, as well as different ways of using adaptive control are also discussed. An overview of applications which includes feasibility studies as well as products based on adaptive techniques concludes the paper.

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Adaptive feedback control

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Adaptive Feedback Control

Modelling of vehicle fuel consumption and emissions has emerged as an effective tool to help develop and assess vehicle technologies and to help predict vehicle fuel consumption and emissions. A review to identify the current state-of-the-art on vehicle fuel consumption and emissions modelling is elucidated. This review categorises vehicle fuel consumption and emissions models into five classifications. The relevant main models to each of these classifications are presented. These models are then compared with regard to assumptions, limitations, merits, drawbacks, characteristic parameters, data collection techniques, accuracy, and relevance to road traffic. The study demonstrates that the trends of vehicle fuel consumption and emissions provided by current models generally do satisfactorily replicate field data trends. In addition, the paper demonstrates that mesoscopic models, empirical models, mean value-based models, and quasi dimensional models strike a balance between accuracy and simplicity and thus are very suitable for transportation and control applications. The study shows as well that no one model as yet fully meets the needs of transportation applications.

Vehicle fuel consumption and emission modelling: an in-depth literature review

Robust low level control of robotic excavation

In a hydraulic system input/output relation of the control valve is nonlinear and load dependent. An adaptive control would therefore be necessary for large changes in load parameter. The paper considers a position control system. This becomes a third order system under inertia load and with compressibility of oil considered. Load pressure and integration of the load pressure are suggested as additional feedbacks. PRBS is used as the input signal and the cross-corelation technique is used for identification of the impulse response. Performance parameters are defined and then they are brought to their respective model parameters by iteratively adjusting the gains of the additional feedback loops. An 8-bit microprocessor based system has been used for identification and control. The proposal seems practical and can be economically implemented.

An Adaptive Control of an Electro-Hydraulic Position Control System

A turbo charged diesel engine without any governor or controller is normally represented by a fourth order model. When the inlet and outlet manifolds are small, their effect is neglected and the model is then simplified to a second order model and does not reflect the effect of the two manifolds. The present paper uses model order reduction technique by Anderson, by separating the dynamics into fast & slow modes and assuming that the fast modes settle quickly. The model has been validated through simulation using typical data. It has been shown that there is a close resemblance in step response between the fourth order and the reduced order model for all the four states. On the other hand, a simpified model, obtained by neglecting the manifold volumes would give erroneous results.

A Reduced Order Model of Turbo Charged Diesel Engine

This paper discusses a situation where a pole as well as a zero of Aircraft-short period T.F. is likely to move to R.H. s plane. The conventional pitch orientation control system would then be inadequate to provide stable control. A modification to the system is suggested in the form of dynamic compensators in the feedforward and feedback paths. Design approach to decide the coefficients of the compensators is given. It is shown that by scheduling just one of the 8 coefficients it may be possible to provide stable control when the pole-zero combination is laying in the L.H. plane as well as when the combination is laying in the R.H. s plane.

Design of a Pitch Orientation Control System for Aircraft Control in Stall Region

The paper proposes a scheme for implementing an adaptive controller design based on Lyapunov stability critarion. Aircraft T.F. consisting of one zero and a complex conjugate pair of poles is considered. The model has also similar structure but the poles are based on HQR considerations. The controller uses analog filters for generating derivatives whereas the parameters are computed and updated by a digital means. The scheme is thus differentiator free. The performance of the scheme has been evaluated by simulating aircraft dynamics plus filters on an Analog computer and then interfacing it to a general purpose Instrumentation & Control digital computer. The results show satisfactory response under widely different Aircraft T.F. including one having an unstable pole.

M. M. Kulkarni

Papers

An Adaptive Control of an Electro-Hydraulic Position Control System

A Reduced Order Model of Turbo Charged Diesel Engine

Design of a Pitch Orientation Control System for Aircraft Control in Stall Region

An MRAC System for Aircraft Longitudinal Control