能动镜中力驱动器的实现及性能测试

用于能动镜中的力驱动器采用直流电机作为驱动源,经减速器后利用滚珠丝杆传动加弹簧组件实现纳米级微位移,而采用丝杆副实现自锁。驱动器基于拉压力传感器实现闭环控制,高增益的PID控制器克服了机械摩擦的微动特性获得比较好的线性度。用4个力驱动器和3个刚性支撑组成了一个能动镜原型样机,光学干涉仪测量结果表明,力驱动器平均位移分辨力约为10nm、最大可变形量达±8μm、最大驱动力达±700N。实验结果证明了力驱动器应用于能动镜驱动器的可行性,为能动镜的实用化提供了实验依据。

大口径望远镜主镜能动支撑驱动器的个体设计和性能测试

大口径望远镜主镜由于体积和质量过大,产生镜面面形变化而影响观测质量。为即时修正面形,现提出了一套力驱动器系统,利用多个该系统组成的能动支撑系统可以对镜体作用达到修正目的。采用了电机、减速器、滚珠丝杠、弹簧组为主要部件,配合传感器和控制器构成了力驱动器系统,并进行了性能实验。实验结果表明,驱动器能够达到设计要求。

一种伺服加载系统的设计与测试

针对气动或液压加载存在的加载力精度不高和需要额外的气源或液压站等特点,研制了一种基于伺服电机和弹性元件的力驱动器及控制系统。针对常规PID不能同时实现良好的动、静态性能的缺点,采用非线性增量PID算法实现力驱动器的全闭环控制;采用3σ准则剔除力传感器及其数据采集系统存在的粗大误差,以提高力控制精度。对力驱动器工程样机进行了性能参数测试,结果表明该力驱动器具有优良的静、动态特性和重复性。

Log evaluation of fractured igneous reservoirs in Songliao Basin

The petrophysical parameters are bad in most igneous reservoirs of Songliao Basin because of the very low porosity and permeability.The evaluation of igneous reservoirs has not been fully studied so far.The current technique of formation evaluation and interpretation used in sedimentary formations face a series of problems and difficulties.In this study,The PCA was used to identify lithology,a multi-mineral model "QAPM" was proposed."Surface effect" must be considered when evaluating saturation.A software "SIMPLE" was developed and was used to deal with the logging data in over 70 wells with good results were achieved.

COGAS Propulsion for LNG Ships

Propulsion of liquefied natural gas (LNG) ships is undergoing significant change. The traditional steam plant is losing favor because of its low cycle efficiency. Medium-speed diesel-electric and slow-speed diesel-mechanical drive ships are in service, and more are being built. Another attractive alternative is combined gas and steam turbine (COGAS) drive. This approach offers significant advantages over steam and diesel propulsion. This paper presents the case for the COGAS cycle.

Impulsive dynamics and stabilization of a single wheel robot

The impulsive motion of a dynamically stabilized robot—Gyrover, which is a single-wheel gyroscopically stabilized robot is studied. A method based on the D’Alembert-Lagrange principle is proposed to develop the impulsive dynamic model of the single wheel robot. This method that can be used to find ways to investigate a single wheel mobile robot rolling on a rough terrain is tested using the experimental platform Gyrover. The conditions of falling over without actuators are addressed. Simulations that validate the analysis are provided as well.

Development of Multi-Fingered Prosthetic Hand Using Shape Memory Alloy Type Artificial Muscle

A new prosthetic hand with a fixed thumb and four fingers actuated by Shape Memory Alloy （SMA） type artificial muscle has been developed in this paper. Different from typical geared motor, SMA actuator is lightweight and silent, however shows a little short stroke and small attracting force per each unit. In order to achieve enough output force and motion range of each finger, multiple SMA type artificial muscles with special device which facilitates enough length are equipped in the hand. The fundamental properties of the SMA type artificial muscle including output force and electrical response were determined experimentally and considered for the design of hand mechanism. Besides, the structure of each finger and whole system has been designed based on observation of human hand. The electrical hardware to control multiple shape memory alloy type artificial muscles has been also developed. Finally, the usefulness of the prosthetic hand has been investigated through experiments for grasping several types of objects.

Basic Characteristics of the Hydraulic-Driven Forceps for Force Feedback

A surgical manipulator has widely been used for laparoscopic surgery. It has been chosen mainly for the use in supporting human operations and in robot systems like the da Vinci surgical system. These manipulator systems are suitable for careful work, but they have a few problems. One of the problems is that the manipulator is not equipped with haptic sensing functions. Therefore, the operator must know the advanced techniques for visually detecting the physical contact state during surgical operations. These haptic sensing functions thus need to be incorporated into a surgical manipulator. We have developed hydraulic-driven forceps with a micro bearing and a bellows tube that can convey haptic sense to the operator. This system can measure the small forces acting on the tips of the forceps using Pascal＇s principle. A model of the system is provided from the relationship between the internal pressure of the bellows tube and the refraction angles of the forceps. It was confirmed using this model that the developed system makes it possible to estimate both the strength and the direction of the external force applied to the forceps by measuring the internal pressure of the bellows tube. An operator using a three-dimensional haptic device was able to feel the force response during an experiment in which they used the forceps to hold a blood vessel. This report describes the most appropriate method for letting the operator feel the force conveyed by using our system.

The Blind Spot of the Sovereign Eye： On the Gaze in Merleau-Ponty and Lacan

In this essay I will explicate the gaze （le regard） and the ways in which it exceeds or transcends what we know as vision, the objectifying or representational power of the eyes. Building critically on Sartre, the gaze in Lacan and Merleau-Ponty is part of the technical apparatus used to describe the foundation, production, and reproduction of the subject. I will begin by discussing the role of visual perception in subject-formation in their respective work, differentiating between the Merleau-Pontian notion of the ＂gaze of the world,＂ i.e., the ways in which things cast their gaze upon us, and the Lacanian gaze as a manifestation of the scopic drive. Through an analysis of anamorphosis I will show （1） how the gaze evades the spectator, （2） what the relationship of the gaze is to the object petit a as the object of the scopic drive, and （3） how both Merleau-Ponty and Lacan require a movement that precedes and destabilizes the subject of intentional consciousness.

Dynamics of mechanical system for electromechanical integrated toroidal drive under electric disturbance

Based on electromagnetics and mechanics, electromechanical coupled dynamic equations for the drive were developed. Using method of perturbation, free vibrations of the mechanical system under electric disturbance were investigated. The forced responses of the mechanical system to mechanical excitation under electric disturbance were also presented. It is known that for the system with electric disturbance, as time grows, beat occurs. When electric disturbing frequency is near to the natural frequencies of the mechanical system or their integer multiple, resonance vibrations occur. The forced responses of the mechanical system to mechanical excitation under electric disturbance are compound vibrations decided by mechanical excitation, electric disturbance and parameters of the system. The coupled resonance vibration caused by electric disturbance and mechanical excitation was discussed as well. The conditions under which above coupled resonance occurs were presented. The results show that when the difference of the excitation frequency and the perturbation frequency is equal to some order of natural frequency, coupled resonance vibrations occur.

Controller design based on viscoelasticity dynamics model and experiment for flexible drive unit

In order to ensure that the system has the advantage of light weight and vibration absorption, the steel rope is used as a flexible transmission part. A flexible drive unit(FDU) is developed, whose features are guided by steel rope, increasing force by the movable pulley group, modular, convenient and flexible. Dynamics model for controller is deduced based on the constitutive equation of viscoelasticity. Controller is designed for position control and is based on the viscoelasticity dynamics model compensation control strategy proposed. The control system is based on the TURBO PMAC multi-axis motion control card.Prototype loading experiments and velocity experiments results show that the FDU can reach 2 Hz with no load and the max speed of 30(°)/s. The FDU has the capability of the load torque 11.2 N·m and the speed of 24(°)/s simultaneously, and the frequency response is 1.3 Hz. The FDU can be used to be the pitch joint of hip for biped robot whose walking speed is 0.144 km/h theoretically.

Pressure Tolerant Power Electronics： IGBT Gate Driver for Operation in High Pressure Hydrostatic Environment

Abstract： This paper presents results from an on-going research project on pressure tolerant power electronics at SINTEF Energy Research, Norway. The driving force for this research is to enable power electronic components to operate in pressurized dielectric environment. The intended application is the converters for operation down to 3,000 meters ocean depth, primarily for subsea oil and gas processing. The paper focuses on the needed modifications to a general purpose gate driver for IGBT （insulated gate bipolar transistors） that will give pressure tolerance. Adaptations and modifications of the individual driver components are presented.The results from preliminary testing are promising, which shows that the considered adaptations give feasible solutions.

A Review of Direct Driven PMSG for Wind Energy Systems

This paper presents a comprehensive overview study of the DDPMSG （direct driven permanent magnet synchronous generator） for wind energy generation system. Wind turbine controls are provided. The PMSG （permanent magnet synchronous generator） is introduced as construction and model. Configurations of different power converters are presented for use with DDPMSG in wind systems at variable speed operation and maximum power capture. Control techniques for the system are discussed for both machine-side and grid-side in details. Grid integration is provided with focus on how to insure power quality of the system and the performance at disturbances.

Electromechanical coupling driving control for single-shaft parallel hybrid powertrain

The single-shaft parallel hybrid powertrain with the automatic mechanical transmission(AMT)is an efficient hybrid driving system in the hybrid electric bus(HEB),while the electromechanical coupling driving control becomes a complicated question to find a transient optimal control method to distribute the power between the engine and the electric machine(EM).This paper proposes an innovative control method to deal with the complicated transient coupling driving process of the electromechanical coupling driving system,considering the accelerating condition and the cruising condition mostly in the city driving cycle of HEB.The EM might be operated at driving mode or generating mode to assist the diesel engine to work in its high-efficiency area.Therefore,the adaptive torque tracking controller has been brought forward to ensure that the EM implements the demand torque as well as compensate the torque fluctuation of diesel engine.The d?q axis mathematical model and back stepping method are employed to deduce the adaptive controller and its adaptive laws.Simulation results demonstrate that the proposed control scheme can make the output torque of two power sources respond rapidly to the demand torque from the powertrain in the given driving condition.The proposed method could be adopted in the real control of HEB to improve the efficiency of the hybrid driving system.

Failure modeling of folded dielectric elastomer actuator

When subjected to voltage,the dielectric elastomer membrane reduces its thickness and expands its area under the resulting compressive force.This characteristic enables the dielectric elastomer actuators of different structures to be designed and fabricated.By employing the thermodynamic theory and research method proposed by Suo et al.,an equilibrium equation of folded dielectric elastomer actuator with two generalized coordinates is established.The governing equations of failure models involving electromechanical instability,zero electric field,electrical breakdown,loss of tension,and rupture by stretch are also derived.The allowable areas of folded dielectric elastomer actuators are described.These results could provide a powerful guidance to the design and performance evaluation of the dielectric elastomer actuators.