多驱动器实现动态大容量影像实时存储

通过对单驱动器磁盘系统和由多驱动器配置构成的磁盘阵列系统存储性能的对比研究发现,多驱动器 配置的磁盘阵列系统是解决动态大容量影像数据实时存储的有效解决方案。在多驱动器配置中应尽量使用具有 异步I/O功能的SCSI磁盘以降低I/O系统对CPU的占用率,同时尽可能采用多个SCSI通道以进一步提高I/O性能。

基于ICLS6021J的E27灯座9WLED灯泡驱动器设计

介绍了带集成650VcOOLMO∥与启动单元的离线式LED电流型控制器ICLS6021J，并讨论了基于ICLS6021J的9WLED灯泡驱动器设计。

分布式电源在仿人机器人控制系统中的应用

为实现仿人机器人无缆工作的时间更长,设计了采用分布式电源的控制系统。仿人机器人关节电机驱动器采用动力电和数字电分开供电的方式,动力电主要为电机供电,而数字电主要为控制芯片供电,因而采用分布式电源方案,即由一个电池组对多个关节驱动器的数字电部分供电,而对单个关节驱动器的动力电部分由一个电池组供电。该方案在搭建的多电机控制系统中验证了其可行性,为仿人机器人无缆工作的时间更长提供了一种可能。

流体动压轴承主轴系统的动态特性实验研究

选用螺旋槽轴承代替球轴承 ,建立了螺旋槽轴承主轴系统模拟试验台 ,研究了螺旋槽轴承主轴系统的动态特性 ,并考察了载荷、速度、轴承间隙以及润滑剂等对其动态特性的影响 .结果表明 :随着转速提高 ,螺旋槽轴承主轴系统的径向和轴向不可重复误差 ( N RRO)均减小 ;载荷对主轴的径向动态特性影响很小 ,但对其轴向动态特性影响较大 ,随着载荷增大 ,轴向 N RRO逐渐减小 ;主轴的径向和轴向 N RRO均随轴向间隙减小而减小 ;随着润滑剂粘度增大 ,主轴径向 NRRO逐渐减小 ,而轴向 NRRO受润滑剂的影响不明显 ;润滑剂粘度越大 。

步进机的输片及供收片控制系统

该系统采用89C205l单片机控制五相混合式步进机。直流力矩电机进行供输片的结构。它由89C2051单片机、步进机、步进机驱动器、步进机输片机构和供输片系统五个部分组成。系统具有两种工作模式，参数可在线修改，使步进机的应用更加灵活方便。

RF MEMS switches based on thermal actuator

A new switching circuit is presented for the application in the frequency range of 0 to 8 GHz. This switch is electro-thermally actuated and exhibits high radio frequency （RF） performance due to its lateral contact mechanism, It composes of electroplated nickel and silicon nitride as structural materials. The isolation between bias and signal ports is realized by using silicon nitride. In the case of a small deformation, the relation between the displacement of the vertex and the pre-bending angle is analyzed. The metal contact is realized by in-plane motion and sidewall connection. The switches were fabricated using the MetalMUMPs process from MEMSCAP. The RF testing results show that the switch has a low insertion loss of 0. 9 dB at 8 GHz and a high isolation of 30 dB below 8 GHz.

Application of direct torque control to electric screw presses for speeding up torque response and reducing starting current

Fast response and stable torque output are crucial to the performance of electric screw presses. This paper describes the design of a direct torque control （DTC） system for speeding up torque response and reducing the starting current of electric screw presses and its application to the J58K series of numerical control electric screw presses with a dual-motor drive. The DTC drive system encompasses speed control, torque reference control, and switching frequency control. Comparison of the DTC dual-AC induction motor drive with corresponding AC servo motor drive showed that for the J58K-315 electric screw press, the DTC drive system attains a higher maximum speed （786 r/min） within a shorter time （1.13 s） during a 250 nun stroke and undergoes smaller rise in temperature （42.0 ℃） in the motor after running for 2 h at a 12 min-1 strike frequency than the AC servo motor drive does （751 r/min within 1.19 s, and 50.6 ℃ rise）. Moreover, the DTC AC induction motor drive, with no need for a tachometer or position encoder to feed back the speed or position of the motor shaft, enjoys increased reliability in a strong-shock work environment.

Electromagnetic drive system of robotic fish

With the aim to apply the electric fish into practice to assist coal mine water disaster life detection and rescue work, based on the analysis on swing propulsion movements of tail fin, this paper integrates the electromagnet technology with tail fin drive system by analyzing how the fish swims with tail fin under the law of progression. The principle, structure, and drive signals of tail fin electromagnetic drive are researched, the enforced situation of fish under eIectromagnetic driving modes are analyzed, and the experimental plat-form of tail fin electromagnetic drive is established. The best distance between electro- magnet and armature, which can realize the swing of tail fin, was researched in the experiment under water. The robotic fish structure parameters of tail fin electromagnetic drive was finalized by theoretical analysis and experimental measurement.

Ultrasonic Linear Motor with Anisotropic Composite

An idea to make up the vibrating body of ultrasonic motor with anisotropic composite is proposed and a linear piezoelectric motor is developed in this paper. Relative problems such as actuating mechanism, resonant frequency are discussed theoretically. According to the feature that impulse exists between the elastic body of composite ultrasonic linear motor and the base, an impulse analysis is presented to calculate the motor′s friction driving force and frictional conversion efficiency. The impulse analysis essentially explains the reason why the ultrasonic motor has great driving force, and can be applied to analyze the non-linear ultrasonic motor.

ACTIVE VIBRATION CONTROL OF A CANTILEVER BEAM USING PIEZOELECTRIC SENSORS AND ACTUATORS

The topic of vibration control with distributed actuators has been the subject of many researches. This paper is concerned with the vibration control of a cantilever beam equipped with piezoelectric ceramics as sensors and actuators. One piezoelectric ceramic is bonded to the structure and provides control input for the structure, while the other piezoelectric ceramic provides the feedback signal. An approach to identification and control is presented. Observation spillover is eliminated by prefiltering the sensor data. A procedure used to determine actuator and sensor location, is discussed based on the modes to be controlled. Finally, the experimental results are presented to verify the proposed method.

Simulation on model predictive control for PMSM drive system based on double extended state observer

A novel double extended state observer(DESO)based on model predictive torque control(MPTC)strategy is developed for three-phase permanent magnet synchronous motor(PMSM)drive system without current sensor.In general,to achieve high-precision control,two-phase current sensors are necessary for successful implementation of MPTC.For this purpose,two ESOs are used to estimate q-axis current and stator resistance respectively,and then based on this,d-axis current is estimated.Moreover,to reduce torque and flux ripple and to improve the performance of the torque and speed,MPTC strategy is designed.The simulation results validate the feasibility and effectiveness of the proposed scheme.

Double ESOs-based field-oriented control for PMSM drive system with current sensorless

A novel double extended state observers(ESOs)-based field-oriented control(FOC)strategy is developed for three-phase permanent magnet synchronous motor(PMSM)drive systems without any phase current sensor.In principle,two current sensors are essential parts of the drive system for implementation of the feedback to achieve high accuracy control.For this purpose,the double ESOs are created to provide feedback stator currents instead of actual current sensors.The first one of the double ESOs is designed to estimate the benchmark value of q-axis stator current,which is a primary premise;While the second is designed to estimate real-time stator currents of d-axis and q-axis simultaneously.The resultant double ESOs can rapidly and accurately give estimation of the actual currents of a-axis,b-axis and c-axis,and the synthesized double ESOs-based FOC strategy for PMSM drive system without any current sensors has satisfactory control performance and strong robustness.Numerical experiments validate the feasibility and effectiveness of the proposed scheme.

Research on Direct Torque Control System Based on Induction Motor

The mathematic model of direct torque control (DTC) was deduced. Two simulating models based on the MATLAB & SIMULINK were established. The emphasis is focused on study of the performance difference of the DTC system with stator flux hexagon and circle trajectories. The simulation waveforms of flux, torque and current characters with two flux trajectories were given. Experiments were carried out in an AC drive system based on induction motor and two-level inverter. A dual-CPU structure was used and the communication with two CPUs was obtained by a dual-port RAM in this system.

Short-circuit fault analysis and isolation strategy for matrix converters

The behavior of matrix converter(MC) drive systems under the condition of MC short-circuit faults is comprehensively investigated. Two isolation strategies using semiconductors and high speed fuses(HSFs) for MC short-circuit faults are examined and their performances are compared. The behavior of MC drive systems during the fuse action time under different operating conditions is explored. The feasibility of fault-tolerant operation during the fuse action time is also studied. The basic selection laws for the HSFs and the requirements for the passive components of the MC drive system from the point view of short-circuit faults are also discussed. Simulation results are used to demonstrate the feasibility of the proposed isolation strategies.

Seismic Isolation of Reactor Assembly for a Fixed Base Accelerator Driven System Reactor Building

In the SILER （Seismic-Initiated events risk mitigation in LEad-cooled Reactors） Project, it is interesting to apply seismic isolation technology for the reactor assembly of the fixed base reactor building for ADS （Acceleration Driven System） heavy liquid reactor MYRRHA （Multipurpose Hybrid Research Reactor for High-Tech Application） which contains the most critical safety related components, such as reactor vessel, safe shutdown and control rod mechanisms, primary heat exchangers, primary pumps, spoliation target assembly and fuel assemblies, etc. The purpose of this paper is to investigate the possibility of an application of a partial seismic isolation to the safety critical components only, here, the reactor assembly. This paper presents the preliminary analysis results of the isolated reactor assembly and compares these with those of seismic isolated ADS reactor building. The analysis results show the reduction of the seismic acceleration response but the increase of the relative displacement for the reactor assembly. Some safety issues, especially, coolant＇s incapable covering the reactor core make difficult to apply for the partial seismic isolation of the ADS reactor assembly due to large relative displacement occurring the partial isolation system. Further study on the partial seismic isolation application of the critical safety components are also discussed.

Analysis of nonlinearities and effects in direct drive electro-hydraulic position servo system

The direct drive electro-hydraulic servo system is a new approach hydraulic system. It is much smaller and easier controlled than traditional systems and is a perfect energy saver. This paper will briefly introduce the popular nonlinearities in the electro-hydraulic system and analyse the effect of nonlinearities in direct drive electro-hydraulic position servo system by means of simulation research. Some valuable conclusions are given.

Sliding-mode control of path following for underactuated ships based on high gain observer

A nonlinear robust control strategy is proposed to force an underactuated surface ship to follow a predefined path with uncertain environmental disturbance and parameters.In the controller design,a high-gain observer is used to estimate velocities,thus only position and yaw angle measurements are required.The control problem of underactuated system is transformed into a control of fully actuated system through adopting an improved line-of-sight(LOS) guidance law.A sliding-mode controller is designed to eliminate the yaw angle error,and provide the control system robustness.The control law is proved semi-globally exponentially stable(SGES) by applying Lyapunov stability theory,and numerical simulation using real data of a monohull ship illustrates the effectiveness and robustness of the proposed methodology.

Research on bionic quadruped robot based on hydraulic driver

A prototype of hydraulically powered quadruped robot is presented. The aim of the research is to develop a versatile robot platform which could travel fleetly in outdoor terrain with long time of en- durance and high load carrying ability. The current version is 1. lm long and 0.48m wide, and weights about 150kg. Each leg has four rotational joints driven by hydraulic cylinders and one pas- sive translational joint with spring. The torso carries the control system and the power system. A no- vel control algorithm is developed based on a Spring-Loaded Inverted Pendulum model and the prin- ciple of joint function separation. The robot can not only cross a 150mm high obstacle in static gait and trot at 2.5km/h and l km/h on the level-ground and 10°sloped-terrain respectively, but also au- tomatically keep balanced under lateral disturbance. In this paper, the mechanical structure and control systems are also discussed. Simulations and experiments are carried out to validate the design and algorithms.

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.