Paolo Lino

Kriging metamodel management in the design optimization of a CNG injection system

This paper deals with the use of Kriging metamodels in multi-objective engineering design optimization. The metamodel management issue to find the tradeoff between accuracy and efficiency is addressed. A comparative analysis of different strategies is conducted for a case study devoted to the design of a component of the injection system for Compressed Natural Gas (CNG) engines. The computational results are reported and analyzed for a performance assessment conducted with a data envelopment analysis approach.

A control-oriented model of a Common Rail injection system for diesel engines

This paper presents a model of a Common Rail injection system for diesel engines. The model is derived by considering the components of the system as control volumes and applying elementary fluid dynamics and mechanics laws. Suitable simplifications are introduced, to make the model adequate for control purposes, trading off between computational effort and accuracy. The model obtained is a fifth order nonlinear one, in state-space representation, and relies on simple, well defined, geometric parameters of the system. The results obtained are compared with data collected on an experimental setup, and with those obtained through the fluid dynamic simulation AMESIMreg

Modeling and predictive control of a new injection system for Compressed Natural Gas engines

The accurate metering of the air/fuel mixture in internal combustion engines equipped with common rail injection systems strictly depends on the injection pressure regulation. This is a critical objective to be accomplished in compressed natural gas injection systems, as the gas compressibility makes the fuel delivery process more complex. Since the design of a controller requires a model of the injection system, in this paper a physics-based state space model of an innovative compressed natural gas injection system is presented. The model parameters only depend on well defined geometrical data and fuel properties. Comparison of simulation and experimental results for different operating conditions validates the model. Further, the proposed model is used for designing a generalized predictive controller (GPC) for the injection pressure regulation. The implementation of the control law consists of simple steps

A new escape routing strategy for controlling evacuation from buildings

This paper proposes an approach for managing crowd evacuation from buildings. The work is motivated by the consideration that chaotic collective motion is a main reason for injuries and deaths during egress in emergency situations. Egress performance can be improved by real time adaptation of escape routes depending on feedback from the real scenario, considering crowd distribution and occurrence of random events. The proposed routing strategy aims at reducing the total egress time by driving individuals towards less congested exits, and is based on the comparison between the predicted evacuation time from each exit. Simulation performed on a simple case study by a commercial software illustrates the feasibility of the approach.

Design and Simulation of Fractional-Order Controllers of Injection in CNG Engines

Abstract Injection systems of compressed natural gas engines exhibit large variations in their parameters and working conditions and are characterized by a highly nonlinear behavior. Therefore, to address the issue of robustness and take into account the different equilibrium points, this paper proposes fractional-order controllers combined with a gain scheduling technique. In particular, a fractional-order PI (or FOPI) controller is designed by loop-shaping, approximated by a rational transfer function, and compared by simulation with an integer order gain-scheduled PI controller. The FOPI controller reduces oscillations in the rail pressure. The scheduling of the FOPI gains improves the robustness to changing work conditions.

Switching Fractional-Order Controllers of Common Rail Pressure in Compressed Natural Gas Engines ⋆

This paper concerns fuel injection control of compressed natural gas engines. The main operating conditions are considered and for each one a fractional-order PI controller is designed. Then at each sudden change of rail pressure and injection timing, a change of the determined controller gains is scheduled. Switching between controllers is driven by step changes of the reference pressure. Robust stability of the designed closed-loop system is guaranteed by D-decomposition. Detailed simulation verifies both dynamic performance and robustness given by the controllers and stability of the switching.

Applying a Discrete Event System Approach to Problems of Collective Motion in Emergency Situations

A proper management of evacuation of crowds in panic situations requires the adaption of strategies and escape routes, depending on information collected from the real scenario. To design an effective supervisory controller, a model representing the main aspects of the evacuation dynamics and based on data coming from a distributed sensors network is necessary. To this aim, a Discrete Event System model is developed here to describe the sequence of events occurring in escape procedures. In particular, a systematic approach consisting of few steps allows to define a modular Petri Net representing flows of individuals during egress. A simple case study shows the feasibility of the proposed method.

A dynamical model of electro-injectors for common rail diesel engines

Research on Common Rail (CR) injection systems has helped to increase the performance of Diesel engines in terms of available power and fuel consumption in compliance with the restrictions of noise and pollutant emissions. To accomplish these tasks, the last generation of electro-injectors is being developed to advance and improve structure and operation in achieving an accurate fuel metering. This paper presents a model of an electro-injector for common rail systems that is able to predict steady-state and transient behavior. Good results are obtained by simulation in different working conditions and match experimental data to a good extent.

Modeling and simulation of crowd egress dynamics in a discrete event environment

In this paper, a queueing network model representing the main aspects of the evacuation dynamics from buildings is developed. A systematic method allows to define in few steps a queueing network representing flows of individuals during egress. In particular, different modules, whose parameters depend on statistical characteristics of motion, are defined for spaces composing the evacuated environment and properly combined. The proposed model is conceived to develop control strategies for real time management of evacuation of crowds, by means of the adaption of strategies and escape routes, depending on information collected from the real scenario. To test the method, a simulation model is implemented in the MATLAB/Simulink© environment, providing a tool suitable for designing and validating evacuation strategies.

Fuzzy adaptive control of a variable geometry turbocharged diesel engine

A fuzzy control approach for the adjustment of the boost pressure of a variable geometry, turbine (VGT) supercharged diesel engine is proposed. The VGT adapts the boost pressure to the target reference for different engine speeds by adjusting the turbine blades, resulting in a reduction of both fuel consumption and gas emissions, while preserving efficiency. We design an adaptive fuzzy control law according to the following steps: first, a standard PI controller is devised, then an equivalent fuzzy controller is built, finally the fuzzy controller is made nonlinear by tuning its input/output parameters using an optimization algorithm. Further, modification of the membership functions is investigated. A large number of simulations on a zero-dimensional model of the engine prove the effectiveness of the proposed control strategy with reference to stability and transient performance in comparison with standard PI techniques.