Preface

**Section 4 Fault Detection 129**

**VI** Contents

Chapter 7 **Root Cause Analysis of Actuator Fault 131**

Mei Zhang, Ze-tao Li, Boutaib Dahhou and Michel Cabassud

The book promotes new research results in the field of modern actuators and their applica‐ tions. In the last years, a huge variety of ideas and results have been published in journals and conferences. Some of them have been developed for industrial production. Smart mate‐ rials and microtechnologies stay as the base of the new actuators and their applications. The book comprehends new coverage of dielectric barrier discharge plasma actuators, polymeric microgripper based on the cascaded V-shaped electrothermal actuators, ionic polymer ac‐ tuators, wideband actuators and energy harvesters, electromagnetic actuators, and shape memory alloy actuators.

The authors have published worked examples and case studies as a result from their re‐ searches in the field. The readers get new solutions and answers to questions related to the emerging actuation principles, fabrication, modeling, simulation, control, fault detection, implementation, and their applications.

In a brief description, the book has four sections: "Design, Fabrication and Simulation of Actuators," "Modeling, System Identification, and Control of Actuators," "Medical Applica‐ tions of Actuators," and "Fault Detection of Actuators."

The book presents in seven chapters cases that illustrate the research results in the above domains. The chapters were edited and published following a rigorous selection process, out of more than double the number of publication proposals.

The first section includes the following chapters: a study carried out to investigate experi‐ mentally and by numerical simulations a microscale plasma actuator; the design, fabrica‐ tion, numerical simulations, and experimental investigations of a polymeric microgripper designed using the cascaded V-shaped electrothermal actuators; a review of the develop‐ ment of ionic polymer actuator with introduction of two kinds of typical polymer actuators —ionic polymer-metal composites and bucky gel actuator—with their basic principle; and fabrication process and typical applications and a methodology of designing and testing wi‐ deband actuators and energy harvesters, treated as one mechanical resonator, with a discus‐ sion on shock harvester, resonant harvester and energy transmission system.

The second section is dedicated to a chapter on modeling, system identification and control of electromagnetic actuators, with main focus on the actuators used in magnetic levitation, in fuel injection systems and in variable valve timing.

The third section presents a study focused on quantifying the decline in tactile sensation associated with diabetic neuropathy, and developed a measurement device that used a thinshaped memory alloy wire as the actuator.

The fourth section includes a chapter presenting a two-level fault diagnosis and root cause analysis scheme for a class of interconnected invertible dynamic systems, which aims at de‐ tecting and identifying actuator fault and the causes.

The editor thanks the authors for their excellent contributions in the field and understand‐ ing during the process of editing. Also, the editor thanks all the editorial personnel involved in this book publication. The publishing provided a set of editorial standards, which ensur‐ ed the quality of the scientific level of relevance of accepted chapters*.*

> **Prof. Constantin Volosencu** "Politehnica" University from Timisoara Romania

**Section 1**

**Design, Fabrication and Simulation**

**Design, Fabrication and Simulation**

The fourth section includes a chapter presenting a two-level fault diagnosis and root cause analysis scheme for a class of interconnected invertible dynamic systems, which aims at de‐

The editor thanks the authors for their excellent contributions in the field and understand‐ ing during the process of editing. Also, the editor thanks all the editorial personnel involved in this book publication. The publishing provided a set of editorial standards, which ensur‐

**Prof. Constantin Volosencu**

Romania

"Politehnica" University from Timisoara

tecting and identifying actuator fault and the causes.

VIII Preface

ed the quality of the scientific level of relevance of accepted chapters*.*

**Chapter 1**

Provisional chapter

**Dielectric Barrier Discharge Microplasma Actuator for**

DOI: 10.5772/intechopen.75802

Dielectric barrier discharge (DBD) plasma actuators are a technology which could replace conventional actuators due to their simple construction, lack of moving parts, and fast response. This type of actuator modifies the airflow due to electrohydrodynamic (EHD) force. The EHD phenomenon occurs due to the momentum transfer from charged species accelerated by an electric field to neutral molecules by collision. This chapter presents a study carried out to investigate experimentally and by numerical simulations a microscale plasma actuator. A microplasma requires a low discharge voltage to generate about 1 kV at atmospheric pressure. A multi-electrode microplasma actuator was used which allowed the electrodes to be energized at different potentials or waveforms, thus changing the direction of the flow. The modification of the flow at various time intervals was tracked by a high-speed camera. The numerical simulation was carried out using the

Keywords: dielectric barrier discharge, microplasma, electrohydrodynamic flow, flow

Active flow control is necessary in various industrial processes to improve system efficiency or to reduce environmental load [1]. In order to achieve flow control, mechanical actuators were developed and used. A new device for flow control was developed by Roth et al. in the 1990s [2]. A dielectric barrier discharge (DBD) was used and it was called a plasma actuator. The nonthermal plasma actuator operates at atmospheric pressure and compared with conventional types of actuators for flow control, has several advantages besides its simple construction, such as no moving parts and fast response [3, 4]. Plasma actuators for flow control were

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

Dielectric Barrier Discharge Microplasma Actuator for

**Flow Control**

Abstract

Flow Control

Kazuo Shimizu and Marius Blajan

Kazuo Shimizu and Marius Blajan

http://dx.doi.org/10.5772/intechopen.75802

control, plasma actuator

1. Introduction

Additional information is available at the end of the chapter

Suzen-Huang model and the Navier-Stokes equations.

Additional information is available at the end of the chapter

#### **Dielectric Barrier Discharge Microplasma Actuator for Flow Control** Dielectric Barrier Discharge Microplasma Actuator for Flow Control

DOI: 10.5772/intechopen.75802

Kazuo Shimizu and Marius Blajan Kazuo Shimizu and Marius Blajan

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.75802

#### Abstract

Dielectric barrier discharge (DBD) plasma actuators are a technology which could replace conventional actuators due to their simple construction, lack of moving parts, and fast response. This type of actuator modifies the airflow due to electrohydrodynamic (EHD) force. The EHD phenomenon occurs due to the momentum transfer from charged species accelerated by an electric field to neutral molecules by collision. This chapter presents a study carried out to investigate experimentally and by numerical simulations a microscale plasma actuator. A microplasma requires a low discharge voltage to generate about 1 kV at atmospheric pressure. A multi-electrode microplasma actuator was used which allowed the electrodes to be energized at different potentials or waveforms, thus changing the direction of the flow. The modification of the flow at various time intervals was tracked by a high-speed camera. The numerical simulation was carried out using the Suzen-Huang model and the Navier-Stokes equations.

Keywords: dielectric barrier discharge, microplasma, electrohydrodynamic flow, flow control, plasma actuator

#### 1. Introduction

Active flow control is necessary in various industrial processes to improve system efficiency or to reduce environmental load [1]. In order to achieve flow control, mechanical actuators were developed and used. A new device for flow control was developed by Roth et al. in the 1990s [2]. A dielectric barrier discharge (DBD) was used and it was called a plasma actuator. The nonthermal plasma actuator operates at atmospheric pressure and compared with conventional types of actuators for flow control, has several advantages besides its simple construction, such as no moving parts and fast response [3, 4]. Plasma actuators for flow control were

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

investigated in applications for separation flow control [5–8] and noise reduction [8, 9]. The plasma actuator has an operating principle based on the electrohydrodynamic (EHD) phenomenon occurring due to the momentum transfer from ions accelerated by an electric field to neutral molecules by collision. Dielectric barrier discharge (DBD) and corona discharge are among the most common types of plasma actuators. A single DBD plasma actuator can induce a flow up to 7 m/s, and with a multiple DBD plasma actuator design, the value of induced flow can reach 11 m/s [10]. Various applications of flow control require different types of plasma actuators. For high-speed flow control, an induced flow speed of more than 7 m/s is necessary; thus instead of using a single DBD plasma actuator, the corona discharge could be used [11–15]. In the case of turbulent boundary-layer control for skin-friction drag reduction, millimeter-size discharge gap DBD plasma actuators were energized at peak-to-peak voltages of about 7 kV [16–19]. Research studies regarding the applications of plasma actuators involve turbulent boundary-layer separation control, steady airfoil leading-edge separation control, oscillating airfoils dynamic stall control, and circular cylinder wake control. According to various researchers, high values of the induced flow are desired. High values of the flow are obtained conventionally by energizing the plasma actuators at tens of kilovolts which are difficult to insulate and for which a large sized power supply is necessary. An effective actuation effect requires also a higher EHD force density that can be achieved using a micrometer order discharge gap plasma actuator, which lowers the discharge voltage and consequently requires lower power. Micro-sized plasma actuators were used for separation flow control and drag reduction [20–22]. A microplasma actuator was developed for flow control [23]. Similar electrode configurations were described in [24–28] but the required discharge voltages are more than 2 kV. Microplasma is a type of dielectric barrier discharge nonthermal plasma and its driven voltage is around only 1 kV. This technology could be used as a replacement of conventional technologies for surface treatment of polymers, indoor air treatment, biomedical applications, or flow control [29–32].

2. Microplasma actuator

actuator to control the flow.

generated [21, 43].

ON state, respectively.

between.

2.1. Experimental study of microplasma actuator

2.1.1. Characteristics of microplasma actuator

A microplasma actuator was developed for flow control. Due to its small size, the experimental results were difficult to obtain near the active electrodes; thus, a numerical simulation was developed in order to simulate the flow and add additional information about the flow. The experimental and numerical simulation results showed the capability of the microplasma

Dielectric Barrier Discharge Microplasma Actuator for Flow Control

http://dx.doi.org/10.5772/intechopen.75802

5

A schematic of the typical construction of a plasma actuator and the induced air flow is shown in Figure 1. A pulse or alternating high voltage is applied to the two electrodes with a dielectric layer in between; thus, a plasma is generated at the surface of the electrodes [42]. An electrohydrodynamic (EHD) phenomenon occurs because ions are accelerated by the electric field and furthermore collide with neutral molecules; thus, a momentum transfer occurs and air flow is

A microplasma actuator that can be driven by a lower voltage of less than 2 kVpp was developed and investigated. Owing to their low discharge voltage, the applied high voltage could be controlled easily using semiconductor switches. The structure of the microplasma actuator is shown in Figure 2 [44]. A dielectric layer consisted of a polymer film of 25-μm thickness sandwiched in between a high voltage electrode and a grounded electrode. Voltages less than 2 kVpp are enough to generate a microplasma due to the thickness of the 25-μm discharge gap. A pulse high voltage power supply was used to energize the actuator with the schematic shown in Figure 3. Four field-effect transistors (FETs) are used with a DC high voltage power supply. The microplasma actuator is energized by a positive pulse voltage while FETs 1 and 4 are in the ON state and by negative pulse voltage while FETs 2 and 3 are in the

Figure 4 shows the experimental setup used to visualize and investigate the air flow induced by the microplasma actuator. The microplasma actuator was set on a Z stage. A high voltage probe (Tektronix, P6105A) connected to an oscilloscope (Tektronix, TDS 3014) was used to

Figure 1. Typical construction of a plasma actuator. High voltage is applied to the electrodes with a thin dielectric layer in

Measurements of microplasma actuators are difficult due to their micrometer size discharge gaps; thus, we have developed a numerical simulation of the induced flow based on the Suzen-Huang [33, 34] and Orlov [35] models. Due to the light emission from microplasma, observation and measurement of flow is difficult. Numerical simulations of the plasma actuator are carried out using the plasma fluid model and particle in cell model [36–39]. A simplified phenomenological model which does not model the species transport equations but can replicate the effects of the actuator in the air is the Suzen-Huang model [40]. Results close to the experimental data were obtained by various researchers who developed numerical simulations based on this model. It is less computationally expensive than solving the species transport equations [40, 41].

The microplasma actuator developed in our laboratory is thin and flexible and can be attached to any surface. To energize the actuator, small-sized power supplies are necessary; thus, a potential use for this actuator could be on drones. The electronic switching adds a greater flexibility in order to obtain flows in various directions. In comparison with macro-plasma actuators where the power supplies are bulky, the small-sized power supply necessary for a microplasma actuator adds little weight to the drone; also, less electrical insulation is necessary.
