Design and Simulation of Electromagnetic Linear Actuators for Jet Dispensers

Abstract

Three electromagnetic-based linear actuators, namely a solenoid actuator (SA), a moving coil actuator (MCA), and a moving magnet actuator (MMA), are proposed for driving the needle in a jet dispenser. The total resistance force acting on the needle during operation, including the damping force, the friction force, the inertia force, the compression spring force, and the backpressure, are measured by an experimental model. The thrust force required to overcome this resistance force is then predicted for each actuator using finite element analysis (FEA) simulations. Simple two-dimensional models of the SA, MCA, and MMA are constructed using the same coil dimensions in every case in order to facilitate an objective comparison between them. Simulations in ANSYS Maxwell software are then performed to adjust the specific dimensions of each actuator structure in such a way as to generate the thrust force required to drive the needle in the jet dispenser with the minimum excitation current possible. The simulation results show that for a maximum needle driving frequency of 250 Hz and a stroke length of 0.5 mm, the excitation current required to generate the necessary thrust force is equal to 1.8 A and 1.9 A for the MCA and MMA models, respectively, when a return spring is not used, and 2.2 A, 3.8 A, and 4.1 A for the SA, MCA, and MMA models, respectively, when a return spring is employed. It is additionally shown that the thrust force drop of the MCA and MMA models is far less than that of the SA model, about 0.7%, 1.8%, and 61% for three models, respectively. Three preliminary designs for jet dispensers incorporating the proposed actuators are also generated for reference purposes.

Sistema de control de posición mediante rechazo activo de perturbaciones para sistemas ópticos láser

“…En diversas aplicaciones de gran precisión como la reportada en este trabajo, el acoplamiento mecánico, las fluctuaciones de voltaje y corriente de la fuente de energía que alimenta el actuador, y las inevitables incertidumbres paramétricas, dificultan garantizar la robustez en el control de posición y de velocidad del servo sistema (Baronti et al, 2009;Tran and Hwang, 2020). En ese sentido, el esquema de control por rechazo activo de perturbaciones ADRC (de sus siglas en inglés, Active Disturbance Rejection Control) introducido por (Han, 2009) es muy atractivo, ya que se basa en la capacidad de estimar en línea, vía un observador de estado extendido ESO (por sus siglas en inglés, Extended State Observer), la parte de la dinámica desconocida del sistema a controlar, así como todos los efectos externos adversos, para posteriormente cancelarlos mediante una apropiada ley de control, (Sira-Ramírez et al, 2015.…”