Multi-physic system simplification method applied to a helicopter flight axis active control

A helicopter flight axis control, which is a complex multi-physic system, is modelled using an energetic based graphical tool: the Energetic Macroscopic Representation. Elements of the system are mainly composed of passive technologies and their number tends to increase year after year to improve the pilots comfort by adding new functions. A new methodology is proposed to transform the system into a new active one by replacing some hydro-mechanical elements by a new controllable active mechanical source. The challenge is to simplify the flight control architecture while preserving the global behaviour of the system

Modeling Stiffness and Damping in Rotational Degrees of Freedom Using Multibond Graphs

A contribution is proposed for the modeling of mechanical systems using multibond graphs. When modeling a physical system, it may be needed to catch the dynamic behavior contribution of the joints between bodies of the system and therefore to characterize the stiffness and damping of the links between them. The visibility of where dissipative or capacitive elements need to be implemented to represent stiffness and damping in multibond graphs is not obvious and will be explained. A multibond graph architecture is then proposed to add stiffness and damping in hree rotational degrees of freedom. The resulting joint combines the spherical joint multibond graph relaxed causal constraints while physically representing three concatenated revolute joints. The mathematical foundations are presented, and then illustrated through the modeling and simulation of an inertial navigation system; in which stiffness and damping between the gimbals are taken into account. This method is particularly useful when modeling and simulating multibody systems using Newton-Euler formalism in multibond graphs. Future work will show how this method can be extended to more complex systems such as rotorcraft blades' connections with its rotor hub.Fondation Airbus Grou

Modelling and Control of an Effort Feedback Actuator in Helicopter Flight Control Using Energetic Macroscopic Representation

In helicopter field, electromechanical devices controllers are usually designed and tuned from global analysis with transfer functions calculations. This leads to control architectures with a reduced number of controllers. Their regulating loops are usually global PID controllers where parameters are directly set up on dedicated test benches. Energetic representation tools such as Energetic Macroscopic Representation (EMR) aim at simplifying systems analysis and control providing model and control structuring method. In this paper, a simplified helicopter flight axis control is modelled with the intention of controlling the helicopter stick force feedback. Performances of both global PID and energetic model based inversion controllers are discussed through simulation results

Modelling and Control of an Effort Feedback Actuator in Helicopter Flight Control Using Energetic Macroscopic Representation

In helicopter field, electromechanical devices controllers are usually designed and tuned from global analysis with transfer functions calculations. This leads to control architectures with a reduced number of controllers. Their regulating loops are usually global PID controllers where parameters are directly set up on dedicated test benches. Energetic representation tools such as Energetic Macroscopic Representation (EMR) aim at simplifying systems analysis and control providing model and control structuring method. In this paper, a simplified helicopter flight axis control is modelled with the intention of controlling the helicopter stick force feedback. Performances of both global PID and energetic model based inversion controllers are discussed through simulation results

Multi-physic system simplification method applied to a helicopter flight axis active control

International audienceA helicopter flight axis control, which is a complex multi-physic system, is modelled using an energetic based graphical tool: the Energetic Macroscopic Representation. Elements of the system are mainly composed of passive technologies and their number tends to increase year after year to improve the pilots comfort by adding new functions. A new methodology is proposed to transform the system into a new active one by replacing some hydro-mechanical elements by a new controllable active mechanical source. The challenge is to simplify the flight control architecture while preserving the global behaviour of the system

Complementary use of BG and EMR formalisms for multiphysics systems analysis and control

In this paper, a complex multiphysics system is modeled using two different energy-based graphical techniques: Bond Graph and Energetic Macroscopic Representation. These formalisms can be used together to analyze, model and control a system. The BG is used to support physical, lumped-parameter modeling and analysis processes, and then EMR is used to facilitate definition of a control structure through inversion-based methodology. This complementarity between both of these tools is set out through a helicopter flight control subsystem

Conception architecturale d’un système mécatronique d’assistance à opérateur par Bond-Graph

Les systèmes mécatroniques requièrent une forte intégration physique et fonctionnelle. Pour répondre au premier besoin, l’usage d’un outil de modélisation multi-physique tel que le Bond-Graph est nécessaire. Son extension à la modélisation fonctionnelle est possible si la description informationnelle des échanges fonctionnels peut être mise sous forme d’action-réaction. Les travaux exposés proposent une méthodologie de conception du niveau architectural d’un système mécatronique d’assistance à l’opérateur, basée sur une modélisation multi-physique et multi-domaine (physique et informationnel) de son cahier des charges.International audienceLes systèmes mécatroniques requièrent une forte intégration physique et fonctionnelle. Pour répondre au premier besoin, l’usage d’un outil de modélisation multi-physique tel que le Bond-Graph est nécessaire. Son extension à la modélisation fonctionnelle est possible si la description informationnelle des échanges fonctionnels peut être mise sous forme d’action-réaction. Les travaux exposés proposent une méthodologie de conception du niveau architectural d’un système mécatronique d’assistance à l’opérateur, basée sur une modélisation multi-physique et multi-domaine (physique et informationnel) de son cahier des charges

Towards an Energetic Modeling of Rotorcraft Using Bond-Graphs

Presented at the AHS 69th Annual Forum, Phoenix, Arizona,May 21 –23, 2013. Copyright © 2013 by the AmericanHelicopter Society International, Inc. All rights reserved.The paper presents an energetic method of helicopters dynamics analysis to study the air resonance (AR)phenomena. First, a brief state of art of AR phenomena is presented and a simple energetic explanation is given.Then part of the state of art is devoted to the Bond Graph (BG) and Multi-Bond Graphs (MBG) modeling methodshowing several advantages of the tool and few examples of MBG researches applications. This work proposes amacroscopic energetic description of a helicopter through the Word Bond Graph representation. The MBG is thenused for Rotor/fuselage structure modeling in order to study the AR phenomena instability. The MBG model resultsare presented and show the potential of the MBG method to predict such a complex phenomenon.International audienceThe paper presents an energetic method of helicopters dynamics analysis to study the air resonance (AR)phenomena. First, a brief state of art of AR phenomena is presented and a simple energetic explanation is given.Then part of the state of art is devoted to the Bond Graph (BG) and Multi-Bond Graphs (MBG) modeling methodshowing several advantages of the tool and few examples of MBG researches applications. This work proposes amacroscopic energetic description of a helicopter through the Word Bond Graph representation. The MBG is thenused for Rotor/fuselage structure modeling in order to study the AR phenomena instability. The MBG model resultsare presented and show the potential of the MBG method to predict such a complex phenomenon

Maximum power point tracking using P&O control optimized by a neural network approach: a good compromise between accuracy and complexity

In the field of power optimization of photovoltaic panels (PV), there exist many maximum power point tracking (MPPT) control algorithms, such as: the perturb and observe (P&O) one, the algorithms based on fuzzy logic and the ones using a neural network approaches. Among these MPPT control algorithms, P&O is one of the most widely used due to its simplicity of implementation. However, the major drawback of this kind of algorithm is the lack of accuracy due to oscillations around the PPM. Conversely, MPPT control using neural networks have shown to be a very efficient solution in term of accuracy. However, this approach remains complex. In this paper we propose an original optimization of the P&O MPPT control with a neural network algorithm leading to a significant reduction of the computational cost required to train it, ensuring a good compromise between accuracy and complexity. The algorithm has been applied to the models of two different types of solar panels, which have been experimentally validated

Efficient energy system modelling for multi-objective optimisation

Energy systems, on which our modern society rely, are in constant transformation. Technological evolution, climate change or the finitude of fossil fuels are some reasons to rethink the centralized, carbon-based energy networks. This way, the design of future energy systems have to take into account multiple concerns, such as local resilience, in addition to technical and economic ones. This paper presents a decision-support tool for the conception of energy systems focusing on the electric vector. The tool was designed using an energy system model implemented in an optimisation algorithm. It takes into account several constraints simultaneously – equilibrium between production and consumption as well as resources availability – and assess the influence of technical parameters on the global performances of the system. An energy system is considered as a combination of production, storage and transport technologies with their operating strategies. The tool’s modularity allows to choose the models adapted to a quick optimisation of energy systems or to an analysis of technical parameters. The second part of the paper presents the optimisation of a local energy system. Search space is composed of production and storage technologies’ number and their operating strategies. Main goals are to find trade-offs between different economic and technical objective-functions – such as levelized cost of energy or local autonomy. Therefore, a genetic algorithm method was used to perform a multi-objective optimisation based on the model. The impact of the operating strategy adopted is underlined.This work was supported by the Region Provence-Alpes-Côte d’Azur, France