An electrostatic induction motor utilizing electrical resonance for torque enhancement

An electrostatic induction motor utilizing electrical resonance to enhance its torque is introduced in this paper. The motor has patterned electrodes embedded on both of its stator and rotor, and driven by three-phase excitation voltage applied to its stator electrodes. The rotor electrodes are connected to external inductances and resistances through slip rings. The torque of the motor is maximized at resonant condition, where the slip frequency is equal to the resonance frequency of the system. A working prototype of the motor was constructed with 18-layered film electrodes. The maximum torque of the motor was 20 mNm at 10 rpm with an excitation by three-phase voltage of 0.9 kV/8.25 kHz. The motor could start itself and rotate in balance with frictions at a speed of 75 rpm with 0.9 kV/8.35 kHz excitation.     

Design and simulation of an ultrasonic linear motor with dual piezoelectric actuators

In this study, an ultrasonic linear motor with dual piezoelectric (PZT) actuators is developed. A traveling wave motion is generated on the stator by a double-sided excitation of the stator of the ultrasonic linear motor, which drives the slider that is connected to the stator. The development and design processes are described. In this paper, the principle of using an ultrasonic motor to drive a traveling wave type is presented. The structure for the ultrasonic linear motor is then demonstrated with its dimensions, driving conditions and material parameters, so that Computer-Aided Engineering (CAE) can be used to simulate the driving performance. The simulation results show the differences to the characteristics that are achieved by adjusting the critical parameters, such as the PZT boned positions, the excitation frequency and the preload, in order to derive the best design. A prototype that uses the best parameter design is presented, and a method to improve development processes is presented in the final section.

     

Linear electrostatic actuators: Gap maintenance via fluid bearings

This paper addresses a novel actuator for manufacturing applications, the “electrostatic artificial muscle.” Artificial muscle is composed of a dense array of small linear actuators. Its promise lies in the prospect of high performance (e.g. higher force-to-weight ratio and peak acceleration than a comparable magnetic motor), clean, quiet operation, and design versatility (especially the elimination of transmissions in many applications). The characteristics of artificial muscle are particularly appealing for applications in robotics and high-speed automation.A model of a linear electrostatic induction motor is presented to illustrate the potential for high performance as well as the difficulty of “gap maintenance.” Gap maintenance refers to the demanding task of preserving a uniform, narrow gap between “slider” and stator in the presence of destabilizing electrostatic forces. A novel approach to gap maintenance, the use of dielectric fluid bearings, is presented. Analysis of a simple, 2-D motor model shows that gap maintenance and motor efficiency may be characterized by two nondimensional parameters: a levitation number, and a gap aspect ratio. It is shown that achieving both low-speed levitation and high efficiency requires long, narrow gaps (high aspect ratio). The results of this analysis are extended to a more complex model featuring an unconstrained, rigid slider. An experimental study of fluid bearings is also presented.     

Torque evaluation of a LIGA fabricated electrostatic micromotor

The dynamic analysis of a twin stator electrostatic wobble motor is presented incorporating finite element electric field predictions and rolling and sliding friction models. The problem of torque measurement in actual devices is then examined and a solution is described which allows the evaluation of torques smaller than 10^-7 Nm without affecting the wobble motion of the device. Theoretical and practical results for actual devices are compared     

表面介质阻挡放电致动器的配置特性研究

沿面介质阻挡放电(SDBD)等离子体发生器在等离子体的产生中起着重要的作用.通过实验和仿真计算相结合的的方法,研究了大气压环境下等离子体发生器的结构对正弦波电源作用下放电的影响.结果表明:相同条件下,对称结构发生器电场强度最大,产生的等离子体分布在正面电极的两侧,等离子体层面积大,亮度高,但消耗功率较大;不对称结构发生器电场强度最低,产生的等离子体在正负电极处对称分布,整体看上去比较均匀;不对称结构底面电极封装之后正面电极处电场强度增强,等离子体分布在正面电极的一侧,亮度居中,底面电极附近的电场降低,抑制了低电极放电消耗能量,但均匀性最差.证明了等离子体激励器的封装抑制了底面电极的放电,同时降低了功耗.     

Bidirectional Electrostatic Actuator Operated With Charge Control

A method for driving an electrically floating, bidirectional electrostatic actuator using high-speed switching and charge control has been proposed and verified experimentally. A macroscopic experiment is used to model the operation of a surface-micromachined microelectromechanical systems (MEMS) device having the form of two parallel electrodes, one rigid, and the other flexible. The movable, or “free” electrode, is connected to ground via a switching device, and the stationary electrode is connected to a single voltage source. The free electrode is alternately charged by induction, then left floating and subjected to a field produced by the stationary electrode. This charge-control mode of operation overcomes the travel range limits associated with the well-known “snap-through” instability. Our proof-of-concept experiment shows that a periodic charging/driving cycle increases the possible travel range of the free electrode by a factor of two over that possible without charge control. The configuration has the potential for use in a variety of optical MEMS applications involving mirror surfaces that must be exposed to the outside world.hfillhbox[1060]     

Non-contact physical activity estimation method based on electrostatic induction technique

We here present a method for measuring human physical activity, which is based on detecting the electrostatic induction current generated by the walking motion under non-contact and non-attached conditions. A theoretical model for the electrostatic induction current generated because of a change in the electric potential of the human body is also proposed. By comparing the obtained electrostatic induction current with the theoretical model, it becomes obvious that this model effectively explains the behavior of the waveform of the electrostatic induction current. The normal walking motions of daily living are recorded using a portable sensor measurement located in an ordinary house. The obtained results show that detailed information regarding physical activity such as a walking cycle can be estimated using our proposed technique. This suggests that the proposed technique, which is based on the detection of the walking signal, can be successfully applied to the estimation of human physical activity.     

交-直-交矿井提升传动系统中定子变压器的功率计算与探讨

分析研究了交-直-交矿井提升变频调速传动系统中定子变压器的功率计算问题,推导出了交-直-交变频调速传动系统中提升电动机和定子变压器的功率计算公式,以实例说明了提升电动机和定子变压器的功率计算方法,并得出了交-直-交矿井提升变频调速传动系统中变压器的功率选择与品牌及控制方式无关,仅与提升机的转矩、提升速度、电动机和变频器的功率因数以及传动系统的效率有关的结论。     

A high-stroke, high-pressure electrostatic actuator for valve applications

This paper presents a novel large-stroke electrostatic valve actuator for high-pressure applications. The combination of pressure balancing and flexible electrode structures ensures large flow gaps at a low actuation voltage. A simulation tool was built to evaluate the design parameters. Design specific, as well as general optimisations are performed. The model shows a 5.6 times (theoretical) performance improvement compared to earlier designs. A micromachined test structure was fabricated and evaluated. Measurement results are presented and discussed.     

Development of a robotic fish using electrostatic film motors: the Seidengyo II robot

We previously built a fish-like robot named Seidengyo I (based on the Japanese words for electrostatic (seiden) and fish (gyo)), which is a light and flexible robot actuated by a novel electrostatic film motor. This paper describes the design features that underlie the operation of Seidengyo II, which is an evolutional prototype of Seidengyo I. These features include an elaborate three-layer electrostatic film motor, a unique power transmission system and a compact robot controller. The power transmission system permits reciprocating power from the three-layer electrostatic actuator to be converted to periodic oscillations of a caudal fin. The robot controller is capable of easily generating high-frequency and high-voltage driving signals. As a result, we can control the oscillations of the caudal fin of Seidengyo II via synchronous operation to achieve open-loop swimming. We present the experimental results regarding the performance of the constructed controller and verify the validity of the design of the Seidengyo II robot by these experimental results.     

Capacitive touchscreen‐integrated electrostatic tactile display with localized sensation

An electrostatic tactile display with a projected capacitive touchscreen integrated into a single panel was demonstrated. Every electrode on the panel is driven for both tactile presentation and the touch sensor. The functions are both time and spatially multiplexed, and a reference–node‐driven high‐pass filter in the touch controller filters out the noise from the tactile driving signals.     

Detection of human respiration based on measurement of current generated by electrostatic induction

In this study, we developed an effective technique for measuring human respiration using a noncontact and nonattached electrode. The technique requires the measurement of the current generated due to the difference in capacitance between a given electrode and the human body. The subpicoampere electrostatic induction current flowing through the electrode when placed a few centimeters from the subject is detected. We propose an occurrence model for the electrostatic induction current generated by the change in capacitance caused by the movement of the body surface while taking a breath. This model effectively describes the behavior of the current flowing through the measurement electrode.     

Resonant-Type Smooth Impact Drive Mechanism Actuator with Two Langevin Transducers

A smooth impact drive mechanism (SIDM) is a unique piezoelectric actuator that is widely used as a camera focusing mechanism, cell phone lens movement mechanism, etc. This principle enables a compact driving mechanism; however, it cannot generate high-speed movement because a soft-type multilayered piezoelectric transducer (PZT) is utilized at off-resonant movement. This paper proposes a resonant-type SIDM actuator driven with hard-type PZTs to realize high-speed and powerful operation. The fundamental principle is also based on the conventional SIDM; therefore, a saw-shaped movement is required. To generate a high-power ultrasonic output, two Langevin transducers are adopted instead of a soft-type multilayered PZT. One Langevin transducer was a stator and the other was slider whose tip was adhered to a carbon fiber reinforced plastic (CFRP) rod. The CFRP rod was connected to the stator transducer with the frictional force. To obtain quasi-saw-shaped vibration, the longitudinal vibration for each Langevin transducer was excited and these movements were added at the connection point at the CFRP rod. In order to combine these vibration modes, the lengths of the stator and slider Langevin transducers were designed to make the resonant frequencies ratio to be 1:2. By using the proposed principle, the slider Langevin transducer was successfully driven with the speed of 0.11 m/s and the output force was 1.8 N with no load.     

Energy analysis of robot task motions

An energy criterion for choosing the best type of manipulator for a specified task is developed. First, the energy required to perform the robotic task is calculated. Then the lower bound of the mechanical energy consumed by the various kinds of manipulators during their motion, while performing a task, is calculated. Thus, the efficiency of a manipulator for the task is determined. Some examples show that the proper selection of the manipulator configuration can reduce the required energy to a quarter of that of a less suitable one. Once the most suitable manipulator is chosen, the criterion for its most energy efficient motion is developed. The model takes into account the kinematic configuration of the robot, gravitational and other external and internal forces acting on the robot during its operation, and the electric motor driving the robot links. Energy optimization of different paths of motion in joint coordinates is discussed briefly.     

Electrostatic tactile display with thin film slider and its application to tactile telepresentation systems

A new electrostatic tactile display is proposed to realize compact tactile display devices that can be incorporated with virtual reality systems. The tactile display of this study consists of a thin conductive film slider with stator electrodes that excite electrostatic forces. Users of the device experience tactile texture sensations by moving the slider with their fingers. The display operates by applying two-phase cyclic voltage patterns to the electrodes. The display is incorporated into a tactile telepresentation system to realize explorations of remote surface textures with real-time tactile feedback. In the system, a PVDF tactile sensor and a DSP controller automatically generate voltage patterns to present surface texture sensations through the tactile display. A sensor, in synchronization with finger motion on the tactile display, scans a texture sample and outputs information about the sample surface. The information is processed by a DSP and fed back to the tactile display in real time. The tactile telepresentation system was evaluated in texture discrimination tests and demonstrated a 79 percent correct answer ratio. A transparent electrostatic tactile display is also reported in which the tactile display is combined with an LCD to realize a visual-tactile integrated display system.     

用于硅基氮化镓可调微镜的静电梳齿型微驱动器设计

提出并设计了一种用于硅基氮化镓(GaN)可调微镜的静电梳齿型微驱动器.利用有限元软件建立了该器件的几何结构模型,对器件的结构进行了仿真优化.此外,采用微机电系统(MEMS)加工工艺,制作出了用于硅基氮化镓可调微镜的梳齿型微驱动器,并对其驱动特性进行测试.测试结果表明:所制作的微驱动器的位移随着电压的变化呈二次方关系,与仿真结果基本一致.当加载驱动电压为200 V时,微驱动器的驱动位移可达到1.08 μm.     

The design and simulation of a novel out-of-plane micro electrostatic actuator

This paper presents a mechanism of developing a novel out-of-plane micro electrostatic actuator capable of causing large out-of-plane deflection. The performance of the actuator is evaluated and simulated by MEMCAD software. Initial analysis results indicated that the usage of both the novel U-shape suspension beam and the electrostatic actuation mechanism permit large rotations motion with respect to the increment of the numbers of electrodes. Moreover, stable rotational motion can be achieved by varying the dimensions of electrode and gap spacing. This design advantage brings the possibility of developing other three-dimensional (3D) structures for on and/or out-of-wafer applications such as optical switch or display.     

高Q值音叉式微陀螺静电自激驱动研究

为了提高检测精度,对研制的具有滑膜阻尼的音叉式微机械陀螺采用静电自激驱动方式,它能够使驱动振动自动稳定在驱动模态的固有频率上,并保持恒定的驱动振动速度幅度。分析了静电自激驱动电路工作原理,采用自动增益控制(AGC)设计制作了相应的检测电路,实现了Q值为325、谐振频率为2.04 kHz微陀螺的闭环恒幅自激振动。     

基于dSPACE的EV电机系统SPS测试平台设计

为了更好地了解电动汽车电机系统的参数特性,提高电机系统的工作运行效率,基于dSPACE搭建了电动汽车电机系统半实物仿真测试平台。利用dSPACE软件和Matlab/Simulink搭建仿真测试模型,结合实际的动力电池和电机系统,完成平台的建立。通过测试平台在不同转速和转矩情况下,对电动汽车电机系统的驱动特性、制动特性和效率特性进行了实验测试研究,分析了特定工况点下电机系统直流母线电压和电流的响应特性,验证了响应的快速性。通过效率实验确定了高效工作区与电机转速、转矩的关系。因此,设计的测试平台可以很方便地进行电机驱动和制动特性的测试,确定电机的高效工作转速和转矩,对电动汽车驱动和制动行驶工况的选取具有重要意义。     

Particle separation in alternating-current electro-osmotic micropumps using field-flow fractionation

This work presents a novel method for continuous particle separation on the microscale by means of field-flow fractionation. It is based on the use of asymmetric interdigitated electrode arrays on the channel bottom, which induce an electro-osmotic channel flow when driven harmonically. Suspended particles are influenced by viscous fluid drag, sedimentation as well as by dielectrophoretic repulsion forces from the driving electrodes due to the emerging electric field. The significant dependance of the present forces on particle properties allows for separation with respect to particle density and size. This work analyzes electric and flow field by means of the finite element method and investigates the size and density dependent particle motion as a function of driving voltage and frequency of the electrode array. Matching these driving parameters permits the separation of sedimenting particles by their density independently from their size as well as the separation by size. Finally, channel designs are proposed which enable standard separation by means of selective particle mobility in the channel, separation in terms of opposing motion directions, as well as continuous lateral separation.