Optimal Actuator Design Research Articles

An optimal design of magnetic actuators using topology optimization and the response surface method

The magnetic actuator is a device that transforms electric energy to mechanical energy. By mechanical energy transformation, some part of the electric energy creates force, and the other part is stored within the ferrous material. An actuator with improved magnetic force can be designed by reducing the stored energy within the ferrous material at the core or the armature. Topology optimization based on the homogenization design method (HDM) is used for the initial design by determining the porous hole size of each element created. The homogenized magnetic permeability is applied in calculation of the magnetic energy stored. The magnetic energy is calculated by finite element analysis and the sensitivity is calculated mathematically by determining the effects of the magnetic energy according to the permeability change at each element. Repeating the process of the porous hole size determination by the sequential linear programming (SLP), eventually leads to a design of an actuator that makes the most improved magnetic force within the limited volume. The initial actuator model derived from topology optimization uses parameter optimization for detail designs. In parameter optimization design, the response surface method (RSM) based on the central composite design is used to obtain a clear final design.

Topology optimization of smart structures: design of piezoelectric plate and shellactuators

In this paper, a novel approach to the design of piezoelectric plate and shellactuators using topology optimization is described. A new piezoelectric materialmodel PEMAP-P (piezoelectric material with penalization and polarization) isproposed, which is an extension of the SIMP (solid isotropic material withpenalization) model used for elastic materials. In addition to the pseudo-densityρ1,which describes the ‘amount’ of piezoelectric material in each finite element, a new design variableρ2 is introduced for the polarization of the piezoelectric material. The optimization problemconsists in distributing the piezoelectric actuators in such a way as to achieve a maximumoutput displacement in a given direction at a given point of the structure, whilesimultaneously minimizing the structural compliance. Sequential linear programming (SLP)is used to solve the optimization problem. Examples are given demonstrating the potentialof the proposed approach for the optimal design of piezoelectric actuators for multi-layerplate and shell structures.

A general analytical model of electrical permanent magnet machine dedicated to optimal design

What is new in this work is the generic capabilities of the proposed analytical model of permanent magnet machines associated with a novel deterministic global optimization method. That allows to solve some more general inverse problem of designing. The analytical approach is powerful to take into account various kinds of constraints (electromagnetical, thermal, etc.). The inverse problem associated with the optimal design of actuators could then be formulated as a mixed‐constrained optimization problem. In order to solve these problems, interval Branch and Bound algorithms which have already proved their efficiency, have made it possible to determine some optimized rotating machines.

Optimal design of PZT actuators in active structural acoustic control of a cylindrical shell with a floor partition

Genetic algorithms (GAs) are employed to optimize locations of PZT actuators in an active structural acoustic control (ASAC) system comprising a cylindrical shell with an internal floor partition. The effect of PZT actuators is simulated using a bending model and an in-plane force model, respectively. The characteristics of the optimal placements of both models are discussed and compared. Numerical simulations demonstrate that for the investigated structure, the in-plane force model has a better control performance than the bending model in the low-frequency range. The underlying physics of the control results are analyzed. Considering the practical applicability of optimally designed ASAC systems, the control performance of the optimal configuration obtained at a single frequency is assessed in the low-frequency range between 100 and 500 Hz, with results showing a significant sound attenuation in the whole range of interest.

The optimal design of piezoelectric actuators for plate vibroacousticcontrol using genetic algorithms with immune diversity

This paper studies the optimal design of piezoelectric actuators forsuppressing noise transmission of a vibration plate. The optimal placement ofthe actuators to reduce the global noise levels is still a significant designproblem, especially placement limited to discrete locations. With the increaseof the alternative locations and number of actuators, a large number of placementpossibilities exist. These multi-dimensional nonlinear problems are verydifficult for traditional optimization methods. In this paper, geneticalgorithms have introduced to solve the problem of optimal discrete placement ofpiezoelectric patches. In order to improve the diversity of the population, anew selection factor is presented that is based on immune diversity, which isdependent on the string denseness and its function value. The survivorprobability of the string with higher denseness will be reduced. Several casesfor a simple supported plate under different load conditions show that theimproved algorithms are efficient.

The effect of load conditions on the design and performance of actuators

This paper demonstrates the effect of dynamic load conditions on the design and performance of actuators. Actuators have both active and passive properties that determine their overall performance. The interaction between the active and passive components of an actuator, and hence the performance, will depend on both the objective (i.e., the actuator used in a control system or as a source) and the dynamics of the structure to which the actuator is attached. It is shown that it is mainly the active properties of an actuator which are affected by the load conditions of the structure. Changes in the active properties due to varying load conditions are demonstrated for various actuator types. By altering the passive properties of an actuator (i.e., mass and stiffness) it is possible to enhance the performance of the actuator used in a particular application. It is shown that the optimal actuator design depends on both the dynamics of the structure to which the actuator is attached and the performance objective. It will be demonstrated that actively changing the passive properties of an actuator allows significant enhancement of performance.

Optimal design of electromechanical actuators for active loads

The proliferation of electromechanical actuation promises reduced maintenance requirements and cost, improved efficiency and reliability, and more environmentally friendly operation. Within this paper, the issue of optimal component selection for actuator design is addressed. Optimality is defined as an engineering trade-off concerning power transfer to the load, efficiency, and torque demand. An equivalent circuit for the actuator/active load system is developed and represented in the phasor domain. Sinusoidal steady-state techniques are employed for system analysis and definition of the conditions for optimality in applications where load force and velocity profiles are known. The actuator application of thrust vector control on the Space Shuttle main engine is specifically addressed.

Optimal design of electromechanical actuators: a new method based on global optimization

The aim of this paper is to show the advantage of a deterministic global-optimization method in the optimal design of electromechanical actuators. The numerical methods classically used are founded either on nonlinear programming techniques (i.e., augmented Lagrangian, sequential quadratic programming) or on stochastic approaches which are more satisfactorily adapted to global optimum research (i.e., genetic algorithm, simulated annealing). However, the latter methods only guarantee reaching this global optimum with some probability. The present paper proposes a deterministic branch and bound algorithm associated with interval arithmetic which is then applied to the dimensioning of a slotless permanent magnet machine. The problem is formulated as a multiobjective-optimization problem with mixed variables. Original and unexpected results in this optimal design are obtained, and comparisons with previous works are presented.