Nano Positioning Control Using Magnetostrictive Actuators

The focus of this thesis is on the development of control systems for nano- positioning actuators using magnetostrictive materials. Magnetostrictive materials have large strokes and fast responses. However, they are less commonly used than other smart materials such as piezoceramics due to their highly nonlinear and hysteretic behaviour. It is necessary to arrive at an accurate model which can predict the material response at any magnetic field and load condition. Furthermore, due to the nonlinearity of the material, a closed-loop feedback system with a stabilizing controller is needed. Different hysteresis models for magnetostrictive materials are implemented and compared. Since load-dependence is one of the main features of hysteresis for magnetostrictive materials, load-dependent models are studied. An existing load- dependent model is implemented and compared with a new load-dependent hysteresis model which is developed by energy considerations. Passivity of the magnetostrictive system was shown using a physical argument. The results are used to develop a stabilizing controller. Using the properties of the Preisach model, an alternative approach for controller design is proposed. Tracking properties and stability of the controllers were shown. An experimental setup has been developed for data collection and model and controller evaluation

Port hamiltonian modeling of MSMA based actuator: toward a thermodynamically consistent formulation.

International audienceThis paper presents a thermodynamically consistent model of MSMA (Magnetic Shape Memory Alloys) under port Hamiltonian framework. It is based on previous works on MSMA proposed in (Gauthier et al., 2008; Calchand et al., 2011). The main di erence lies in the choice of the state variables and manipulated thermodynamic forces. Furthermore in (Gauthier et al., 2008), subsequent experiments revealed a highly hysteretic behavior of these materials. Here, the simpli ed hysteretic behavior is incorporated into the port-hamiltonian model to obtain a ner and more precise model. Such modeling will allow the use of a wide range of energy based methods to design the associated control system. The paper ends with some extensions to more complex hysterestic phenomena by using Preisach like model. First ideas are proposed to extend the previous physical model to systems with internal hysteretic loops

On the characterization of butterfly and multi-loop hysteresis behavior

While it is widely used to represent hysteresis phenomena with unidirectional-oriented loops, we study in this paper the use of Preisach operator for describing hysteresis behavior with multidirectional-oriented loops. This complex hysteresis behavior is commonly found in advanced materials, such as, shape-memory alloys or piezoelectric materials, that are used for high-precision sensor and actuator systems. We provide characterization of the Preisach operators exhibiting such input-output behaviors and we show the richness of the operators that are capable of producing intricate loops

Application of Rotating Arms Type Permanent Magnet Motor

The present application related to a rotating arm type permanent magnet motor, in particular to a permanent magnet motor that was actuated by the action of the magnetic forces of a permanent magnet stator of a stator module and two thin ring permanent magnets of a rotor module. The purpose of present permanent magnet motor was to provide the torque produced by a magnetic force of the magnetic energy of a stator to drive the rotation of the rotor. The rotating arm type permanent magnet motor comprised an external support frame base, a stator module and a rotor module. The external support frame base included an upper frame, a lower frame and two side frames. The stator module included an elastic metal plate cantilever arm and a permanent magnet stator. The rotor module included a rotating shaft, a double arc shaped rotating arms type support frame, and two thin ring permanent magnets. Magnet material N45H (sintered Nd–Fe–B) was used for the permanent magnets of stator and rotor. The values of magnetic forces (attraction force and exclusion force) were inverse proportional to the position distances of poles (N pole and S pole) above the top level of thin ring permanent magnets, e.g. c= 12mm. The greater value of magnetic forces got the faster rotation speed. The values of magnetic forces could produce the good enough torque for the thin ring permanent magnets to rotate the shaft when position b= 8mm better than that when position b= 17mm. In the future, with the help of using an external swing motion of electrical controlled swing-type device to produce complete rotation, the present permanent magnet motor might save electricity and power sources. Some preliminary rotation speed data of rotating shaft in a permanent magnet motor were obtained and presented with manually controlled

Modeling and control of micro-mechatronic devices : application of variational and energetic methods for micro-actuator design.

International audienceThis paper is focused on a modeling procedure wellsuited for the design of micro-mechatronic systems and especially for micro-actuators. The purpose of this publication is to show that the variational and energetical methods is not only wellsuited to model classical micro-mechatronic devices but that they are also well-suited to include complex dynamical behaviour such as non-linearity and hysteretical behaviour. This procedure is applied to the design of a new actuator using one of the relatively new smart materials, the Magnetic Shape Memory Alloys (MSMAs). It should be stressed that the presented approach can be extented to a great range of other smart materials and that the description can be easily extented up to the control level

Conversion d'énergie magnéto-thermo-mécanique dans les alliages à mémoire de forme magnétiques.

National audienceLes matériaux actifs sont de plus en plus utilisés en tant qu'actionneurs dans les systèmes mécatroniques et micro-mécatroniques. Les matériaux piézoélectriques et les alliages à mémoire de forme sont les deux exemples les plus représentatifs à l'heure actuelle dans ces domaines. Les alliages à mémoire de forme magnétiques sont des matériaux relativement récents et ils apparaissent très intéressants de par leur rapidité d'actionnement et leur grande déformation ; cependant, leur comportement fortement non-linéaire reste un frein à leur développement et les méthodes de conception et de commande les concernant se doivent d'évoluer

From canonical Hamiltonian to Port-Hamiltonian modeling application to magnetic shape memory alloys actuators.

International audienceThis paper presents the modelling of an actuator based on Magnetic Shape Memory Alloys (MSMA). The actuation principle relies on the ability of the material to change its shape under the application of a magnetic field. Previous models proposed by authors were based on canonical (symplectic) Hamiltonian modeling and thermodynamics of irreversible processes. These models, though physically cogent, are non-minimal differential algebraic dynamical models and hence less adapted for control purposes.This paper therefore proposes a modified and systemoriented modeling procedure which lends itself naturally to a port-Hamiltonian model. The latter is found to be a minimal realization of the above whereby interconnection between subsystems is clearly visible. Using Lagrange multipliers, constraints which arise due to causality and interconnection are expressed. In the last section, Differential Algebraic Equations (DAE) resulting from previous models are reduced to Ordinary Differential Equations (ODE) and by using coordinate transformations, constraints are decoupled from the system input/output. The resulting model is well-suited for control