PI adaptive neuro-fuzzy and receding horizon position control for intelligent pneumatic actuator

Pneumatic systems are widely used in automation industries and in the field of automatic control. Intelligent Pneumatic Actuators (IPA) is a new generation of actuators designed and developed for research and development (R&D) purposes. This work proposes two control approaches, Proportional Integral Adaptive Neuro-Fuzzy (PI-ANFIS) controller and Receding Horizon Controller (RHC), for IPA position control. The design steps of the controllers are presented. MATLAB/SIMULINK is used as a tool to implement the controllers. The design is based on a position identification model of the IPA. The simulation results are analyzed and compared with previous work on the IPA to illustrate the performance of the proposed controllers. The comparison shows a significant improvement in IPA position control after using the new controller

RF MEMS inductors and their applications - a review

Inductors are primary elements in many radio frequency circuitries and devices. This review gives a comprehensive survey on the developments and performances of fixed and variable RF MEMS inductors. MEMS inductors are the core of this review due to their high-yield performances and the wide choices of possible tuning techniques. First, the factors that constrain high-performance micro coils and the conventional solutions to overcome them are highlighted. Next, this paper systematically reviews varieties of MEMS inductors starting with the fixed inductors and according to inductors' topologies and performance enhancement techniques. In addition, the variable types of inductors are subsequently discussed, mainly from the point of view of their tuning techniques. Many quantitative comparisons are given in terms of the values of quality factor, inductance, self-resonance frequency, and tuning range. This will provide readers with an overall evaluation of different studies and assist them in choosing the inductors' topologies and layouts that best suit their applications. This review also sheds light on different and most common RF MEMS inductors applications, including RF communication devices and wireless sensors and actuators applications. Finally, this paper summarizes the best fabrication and tuning approaches inferred from the reviewed works and discusses some design guidelines to achieve better inductor performance

Design and fabrication of a novel XY theta z monolithic micro-positioning stage driven by NiTi shape-memory-alloy actuators

This paper reports a new shape-memory-alloy (SMA) micro-positioning stage. The device has been monolithically micro-machined with a single fabrication step. The design comprises a moving stage that is manipulated by six SMA planar springs actuators to generate movements with three degrees of freedom. The overall design is square in shape and has dimensions of 12 mm x 12 mm x 0.25 mm. Localized thermomechanical training for shape setting of SMA planar springs was performed using electrical current induced heating at restrained condition to individually train each of the six actuators to memorize a predetermined shape. For actuation, each SMA actuator is individually driven using Joule heating induced by an electrical current. The current flow is controlled by an external pulse-width modulation signal. The thermal response and heat distribution were simulated and experimentally verified using infrared imaging. The micro-positioning results indicated maximum stage movements of 1.2 and 1.6 mm along the x- and y-directions, respectively. Rotational movements were also demonstrated with a total range of 20 degrees. The developed micro-positioning device has been successfully used to move a small object for microscopic scanning applications

Predictive Functional Control With Observer (PFC-O) Design And Loading Effects Performance For A Pneumatic System

Demand for higher accuracy and control systems is growing rapidly and becomingmore important in high-tech industries. However, precise position control of a pneumatic cylinder is very difficult to achieve due to the compressibility of air, nonlinear behavior of the air flow rate through the valves and the friction force between the cylinder and the piston of the system. The purpose of this paper was to present a model and a novel linear process control strategy to design a position controller for a real-time pneumatic system. This paper mainly analyzes the horizontal and vertical precision positioning control under loading effect for pneumatic system in real-time experiment. System identification approach is selected to obtain the plant model. Predictive Functional Control with observer (PFC-O) design is proposed as control strategy to improve tracking performance of the pneumatic system. Performance assessment of the controller was performed in MATLAB. The effectiveness of the proposed control strategy is verified through real-time experiment with the plant. The simulation and the experimental results confirm that the proposed PFC-O controller shows good control performance with various load configurations