Precision Improvement in Inertial Miniaturized Navigators Based on Fuzzy Logic Denoising of Sensors Signals

The chapter presents a new strategy to improve the precision of the inertial navigators processing in a fuzzy manner the signals provided by the miniaturized sensors equipping their inertial measurement units (IMU). To apply the developed technique, the hardware component of the inertial measurement units was specifically designed to include some redundant clusters of inertial sensors disposed in linear configurations on the measurement axes. The algorithm acts at the level of each detection cluster designed to measure an acceleration or angular speed along with an IMU axis by fusing the data obtained from the sensors in respective cluster. Based on the standard deviations of the sensors signals estimated for a data frame with a well-known size, the fuzzy logic mechanism provides a set of weights associated with each sensor in cluster, which are further used to fuse the data acquired from sensors at the current time. The algorithm has an adaptive character, the data frame used to estimate the standard deviations of the sensors signals being permanently updated with the new sensors measurements, and, in this way, the weights associated with each sensor are reestimated at each measurement step

Design and experimental testing of a control system for a morphing wing model actuated with miniature BLDC motors

Abstract The paper deals with the design and experimental validation of the actuation mechanism control system for a morphing wing model. The experimental morphable wing model manufactured in this project is a full-size scale wing tip for a real aircraft equipped with an aileron. The morphing actuation of the model is based on a mechanism with four similar in house designed and manufactured actuators, positioned inside the wing on two parallel lines. Each of the four actuators used a BrushLess Direct Current (BLDC) electric motor integrated with a mechanical part performing the conversion of the angular displacements into linear displacements. The following have been chosen as successive steps in the design of the actuator control system: (A) Mathematical and software modelling of the actuator; (B) Design of the control system architecture and tuning using Internal Model Control (IMC) methodology; (C) Numerical simulation of the controlled actuator and its testing on bench and wind tunnel. The morphing wing experimental model is tested both at the laboratory level, with no airflow, to evaluate the components integration and the whole system functioning, but also in the wind tunnel, in the presence of airflow, to evaluate its behavior and the aerodynamic gain

A Self–Tuning Intelligent Controller for a Smart Actuation Mechanism of a Morphing Wing Based on Shape Memory Alloys

The paper exposes some of the results obtained in a major research project related to the design, development, and experimental testing of a morphing wing demonstrator, with the main focus on the development of the automatic control of the actuation system, on its integration into the experimental developed morphing wing system, and on the gain related to the extension of the laminar flow over the wing upper surface when it was morphed based on this control system. The project was a multidisciplinary one, being realized in collaboration between several Canadian research teams coming from universities, research institutes, and industrial entities. The project’s general aim was to reduce the operating costs for the new generation of aircraft via fuel economy in flight and also to improve aircraft performance, expand its flight envelope, replace conventional control surfaces, reduce drag to improve range, and reduce vibrations and flutter. In this regard, the research team realized theoretical studies, accompanied by the development and wind tunnel experimental testing of a rectangular wing model equipped with a morphing skin, electrical smart actuators, and pressure sensors. The wing model was designed to be actively controlled so as to change its shape and produce the expansion of laminar flow on its upper surface. The actuation mechanism used to change the wing shape by morphing its flexible upper surface (manufactured from composite materials) is based on Shape Memory Alloys (SMA) actuators. Shown here are the smart mechanism used to actuate the wing’s upper surface, the design of the intelligent actuation control concept, which uses a self–tuning fuzzy logic Proportional–Integral–Derivative plus conventional On–Off controller, and some of the results provided by the wind tunnel experimental testing of the model equipped with the intelligent controlled actuation system. The control mechanism uses two fuzzy logic controllers, one used as the main controller and the other one as the tuning controller, having the role of adjusting (to tune) the coefficients involved in the operation of the main controller. The control system also took into account the physical limitations of the SMA actuators, including a software protection section for the SMA wires, implemented by using a temperature limiter and by saturating the electrical current powering the actuators. The On–Off component of the integrated controller deactivates or activates the heating phase of the SMA wires, a situation when the actuator passes into the cooling phase or is controlled by the Self–Tuning Fuzzy Logic Controller

Fuzzy Logic-Based Control for a Morphing Wing Tip Actuation System: Design, Numerical Simulation, and Wind Tunnel Experimental Testing

The paper presents the design, numerical simulation, and wind tunnel experimental testing of a fuzzy logic-based control system for a new morphing wing actuation system equipped with Brushless DC (BLDC) motors, under the framework of an international project between Canada and Italy. Morphing wing is a prime concern of the aviation industry and, due to the promising results, it can improve fuel optimization. In this idea, a major international morphing wing project has been carried out by our university team from Canada, in collaboration with industrial, research, and university entities from our country, but also from Italy, by using a full-scaled portion of a real aircraft wing equipped with an aileron. The target was to conceive, manufacture, and test an experimental wing model able to be morphed in a controlled manner and to provide in this way an extension of the laminar airflow region over its upper surface, producing a drag reduction with direct impact on the fuel consumption economy. The work presented in the paper aims to describe how the experimental model has been developed, controlled, and tested, to prove the feasibility of the morphing wing technology for the next generation of aircraft

Tuning of a Wavelet Filter for Miniature Accelerometers Denoising based Joint Symbolic Dynamics (JSD) Method

The paper exposes a wavelet filtering mechanism related to the noise suppression in the acceleration sensors, with direct application in the strap-down inertial navigation systems. The presented procedure is related to the actual trend in the inertial navigation field to use miniaturized inertial measurement units, which includes MEMS or NEMS sensors. Beside the already wavelet filtering used method, based on different thresholding mechanisms, the here proposed work refers to the use of an alternative tuning mechanism for the wavelet filters, based on the Joint Symbolic Dynamics (JSD) method. The main idea of the proposed method is to process and analyze signals received from the sensors in the inertial measurement unit of the navigator by using the Wavelet transform until optimal levels of decomposition are established and the useful signals are achieved

Inertial Sensor Signals Denoising with Wavelet Transform

In the current paper we propose a new software procedure for processing data from an inertial navigation system boarded on a moving vehicle, in order to achieve accurate navigation information on the displacement of the vehicle in terms of position, speed, acceleration and direction. We divided our research in three phases. In the first phase of our research, we implemented a real-time evaluation criterion with the intention of achieving real-time data from an accelerometer. It is well-known that most errors in the detection of position, velocity and attitude in inertial navigation occur due to difficult numerical integration of noise. In the second phase, we were interested in achieving a better estimation and compensation of the gyro sensor angular speed measurements. The errors of these sensors occur because of their miniaturization, they cannot be eliminated but can be modelled by applying specific signal processing methods. The objective of both studies was to propose a signal processing algorithm, based on Wavelet filter, along with a criterion for evaluating and updating the optimal decomposition level of Wavelet transform for achieving accurate information from inertial sensors. In the third phase of our work we are suggesting the utility of a new complex algorithm for processing data from an inertial measurement unit, containing both miniaturized accelerometers and gyros, after undergoing a series of numerical simulations and after obtaining accurate information on vehicle displacemen

Proportional fuzzy feed-forward architecture control validation by wind tunnel tests of a morphing wing

In aircraft wing design, engineers aim to provide the best possible aerodynamic performance under cruise flight conditions in terms of lift-to-drag ratio. Conventional control surfaces such as flaps, ailerons, variable wing sweep and spoilers are used to trim the aircraft for other flight conditions. The appearance of the morphing wing concept launched a new challenge in the area of overall wing and aircraft performance improvement during different flight segments by locally altering the flow over the aircraft’s wings. This paper describes the development and application of a control system for an actuation mechanism integrated in a new morphing wing structure. The controlled actuation system includes four similar miniature electromechanical actuators disposed in two parallel actuation lines. The experimental model of the morphing wing is based on a full-scale portion of an aircraft wing, which is equipped with an aileron. The upper surface of the wing is a flexible one, being closed to the wing tip; the flexible skin is made of light composite materials. The four actuators are controlled in unison to change the flexible upper surface to improve the flow quality on the upper surface by delaying or advancing the transition point from laminar to turbulent regime. The actuators transform the torque into vertical forces. Their bases are fixed on the wing ribs and their top link arms are attached to supporting plates fixed onto the flexible skin with screws. The actuators push or pull the flexible skin using the necessary torque until the desired vertical displacement of each actuator is achieved. The four vertical displacements of the actuators, correlated with the new shape of the wing, are provided by a database obtained through a preliminary aerodynamic optimization for specific flight conditions. The control system is designed to control the positions of the actuators in real time in order to obtain and to maintain the desired shape of the wing for a specified flight condition. The feasibility and effectiveness of the developed control system by use of a proportional fuzzy feed-forward methodology are demonstrated experimentally through bench and wind tunnel tests of the morphing wing model