A linear motor damper for vibration control of steel structures

A hybrid mass damper based on the linear motor principle is developed to suppress structural vibration. We will call it a linear motor damper in this paper. This paper deals with the design, analysis, and manufacture of the linear motor damper. It consists of the NdFeB permanent magnets, a coil-wrapped nonmagnetic hollow rectangular structure, an iron core, mechanical springs, and so on. It is designed to be able to move the auxiliary mass of 1500 kg, up to ±250 mm stroke. A series of performance tests for the linear mass damper with H_∞ robust controller are carried out on a steel frame structure. Through performance tests, it is confirmed that the developed hybrid mass damper has reliable feasibility as a control device for structural control. In addition, the linear motor damper is more economical than both hydraulic and electric motor driving mass damper with respect to simple structure and low maintenance cost.     

An optimal tandem active-passive suspension system for roadvehicles with minimum power consumption

The authors examine the problem of the synthesis of an optimal control law for active suspensions of road vehicles, based on a model with two degrees of freedom. The possibility of realizing the desired optimal control law with a tandem active-passive suspension is considered. The procedure for determining the desired optimal control law on the basis of suitable design specification is outlined. In the case of a suspension with two degrees of freedom, the possibility of realizing a control law with an active suspension in tandem with a conventional passive one consisting of a spring and a damper is examined. The characteristic parameters of the passive part of the suspension are identified with the aim of minimizing the power required by the active part. The expressions for calculating the values of the elastic constant of the spring and of the characteristic coefficient of the damper, which are both assumed to be linear, are provided. An example of the application is presented     

Fuzzy Sliding-Mode Control of Active Suspensions

In this paper, a robust fuzzy sliding-mode controller for active suspensions of a nonlinear half-car model is introduced. First, a nonchattering sliding-mode control is presented. Then, this control method is combined with a single-input–single-output fuzzy logic controller to improve its performance. The negative value of the ratio between the derivative of error and error is the input and the slope constant of the sliding surface of the nonchattering sliding-mode controller is the output of the fuzzy logic controller. Afterwards, a four-degree-of-freedom nonlinear half-car model, which allows wheel hops and includes a suspension system with nonlinear spring and piecewise linear damper with dry friction, is presented. The designed controllers are applied to this model in order to evaluate their performances. It has been shown that the designed controller does not cause any problem in suspension working limits. The robustness of the proposed controller is also investigated for different vehicle parameters. The results indicate the success of the proposed fuzzy sliding-mode controller.      

Control of magnetorheological dampers for vibration reduction in a washing machine

The aim of this work is the analysis and design of a control system for vibration and noise reduction in a washing machine. The control system is implemented via a semi-active magnetorheological (MR) damper located on the suspension that links the drum to the cabinet. The entire design procedure is outlined: first, the semi-active actuator is described and an experimental protocol is proposed and tested; two adaptive control strategies are proposed, designed and tested. Some experiments are done in an anechoic chamber to assess the noise reduction. The reported results show the effectiveness of the proposed control system.     

H∞ control of electrorheological suspension system subjected to parameter uncertainties

Vehicle suspension is normally used to attenuate unwanted vibration from various road conditions. The successful suppression of the vibration leads to the improvement of ride comfort as well as steering stability of the vehicle. One of attractive candidates to formulate successful vehicle suspension is to use electrorheological (ER) damper. This paper presents robust control performances of ER suspension system subjected to parameter uncertainties associated with sprung mass of the vehicle and time constant of the ER damper. After identifying dynamic bandwidth of a cylindrical ER damper operated with two different ER fluids (one has fast response characteristic, while the other slow response characteristic), a quarter car model is established by incorporating with time constant of the damping force. A robust H_∞ controller, which compensates the sprung mass and time constant uncertainties, is designed in order to suppress unwanted vibration of the vehicle. Control responses such as vertical acceleration of the sprung mass are presented in time and frequency domains. In addition, the effect of time constant of the damping force on the vibration control performance is investigated by undertaking a comparative work between fast and slow dynamic characteristics of the ER damper.     

Computer-aided design and analysis of direct-driven wheel motordrive

This paper presents the computer-aided design (CAD) and performance analysis of a novel direct-driven wheel brushless DC motor drive for electric vehicles (EVs). The proposed motor is a permanent magnet square-wave motor, whose rotor with rare earth magnets forms the exterior of the motor, which can be fitted with a wheel tire to realize the direct drive for each wheel of an EV. The interior stator with its windings is rigidly mounted onto the suspension and frame structure of the vehicle. In order to achieve the direct drive without any mechanical transmission for EVs, the wheel motor has been designed as a low-speed high-torque motor. The design and optimization of the motor geometry was achieved with the aid of finite-element electromagnetic field analysis. Simulation studies on the transient performance of the motor drive were also carried out. This involved the creation of the motor transient model and formulation of a motor control strategy to ensure the wheel motor drive runs efficiently in the entire permitted speed and load range. The application of CAD techniques in the design of this very unconventional drive is described in this paper     

Design of a perturbation estimator using the theory ofvariable-structure systems and its application to magnetic levitationsystems

A perturbation estimator using the theory of variable structure systems is proposed to enhance the robustness of a pole-placement controller design. In its ideal form, the pole-placement design using feedback-linearization technique achieves a desired performance in nonlinear time-varying systems. However, its performance deteriorates rapidly with the presence of disturbance and parametric uncertainties, referred to as perturbation. The estimate generated by the proposed perturbation estimator is incorporated as an additional input to rectify the uncertainties in the nominal control model of the pole-placement design. The proposed scheme requires neither the measurement of the time derivative of the state vector nor the precise knowledge of system parameters, hut rather the bounds on system perturbation. Chatter and the adverse effects of conservative bounds on system perturbation, often encountered in conventional sliding-mode control (SMC), are alleviated for the controlled plant by the proposed scheme. The benefits of this scheme are demonstrated in this study practically on a magnetic levitation system and its performance is compared with that of the conventional SMC scheme     

An electronic controller for adaptive suspension

Developing an adaptive suspension system for a luxury car weighing over 2000 kg presents an exacting challenge in embedded control. This article describes the development of an adaptive suspension controller by Lamerholm Fleming Ltd for Rolls-Royce Motor Cars Ltd. during the period from 1995 to 1997. The controller replaced an earlier design, which had originally entered production in 1989. The new system uses hydraulic dampers (shock absorbers) which can be switched between three different settings by means of two solenoid controlled valves. Each damper setting provides a different complex force/velocity response for bounce and rebound. These mechanical characteristics are determined by the precise magnitudes of springs and orifices within the damper. The function of the electronic controller is to select the optimum damper setting for any particular driving conditions and to choose the best time to switch from one setting to another. The aim of the whole suspension system is to provide the best possible compromise between ride, comfort and handling     

High energy efficiency oriented-control and design of WFSM based on driving condition of electric vehicle

The purpose of this paper is to increase the energy efficiency of an electric vehicle (EV) with a wound-field synchronous motor (WFSM). Therefore, methods are proposed to estimate and improve the energy efficiency of the EV as well as the performance of the WFSM. The following contributions are provided: 1) EV model as well as the mathematical model of the electric motor are explained considering the common Artemis driving cycle (CADC); 2) a control method for maximizing the energy efficiency of the electric motor is proposed; 3) analysis methods for calculating the circuit parameters (resistance, inductance, and flux linkage) and losses (ohmic, iron, and mechanical loss) are described. The efficiency of the machine is accurately determined using the proposed analysis method; 4) based on the proposed methods, the design process of the WFSM is proposed to improve the energy efficiency considering the vehicle system and driving cycle; and 5) the proposed methods are verified through tests of the prototype and improved motor. As a result, through the proposed design and control method, even though the volume of the improved motor was 7.8% smaller than that of the prototype, the efficiency of the improved motor was higher than that of the prototype in all regions. In addition, to confirm the effectiveness of the proposed methods, the performance of the electric vehicle considering the driving cycle was analyzed according to the characteristics of the electric motor. The energy loss of the improved motor with the proposed control and design method was 63.3% less than that of the prototype. Accordingly, the energy efficiency of the vehicle system and the energy consumption of the battery increased by 7.8%p and decreased by 2.0 kWh, respectively.     

新型旋片式空中电场传感器及应用

该文介绍一种新型的空中电场传感器,它利用导体在电场中感应电荷的原理,通过感生电荷的 变化检测电场强度。传感器采用了新型的双定子结构以及独特的电路设计,有效地屏蔽了空中积累电荷以及 空间离子流对测量的影响。本器件用以检测100V/m-50000V/m的高空电场,误差小于5％。此传感器 已进行地面至15km空中电场探测试验,得到满意的空中电场测试数据。     

Control and experimental study of 6-DOF vibration isolation platform with magnetorheological damper

Vibration is an inevitable excitation in the operation of the mechanical system, which reduces its reliability and service life. Therefore, a heavy-duty 6-DOF semi-active vibration isolation system (VIS) with magnetorheological (MR) damper was proposed in this paper. Firstly, A MR damper with large output force of 27 kN was designed. The properties test results showed that the dynamic range (the adjustable multiple of damping force) of the damper is as high as 15, which has excellent dynamic performance. And a Bouc-Wen model which can accurately describe the mechanical behavior of the MR damper was established. Secondly, the prototype of the MR 6-DOF vibration isolation platform (VIP) with cubic structure was developed. Thirdly, a on-off semi-active control strategy was proposed for the MR 6-DOF VIP. The numerical simulation results showed that the semi-active VIS can effectively isolate vibration in the working frequency domain. Finally, the vibration experiment on shaking table was carried out. The test results showed that the designed heavy-duty MR 6-DOF semi-active VIP can control the load's attitude in real-time according to the system state. Compared with the current of 0 A, the vibration isolation effect of the on-off control is improved by 63.27% in the resonance region. The MR 6-DOF VIP can effectively reduce the vibration transmitted to the isolated system through the platform.     

Optimal design of MR damper via finite element analyses of fluid dynamic and magnetic field

In the last decade many researchers have been carried out on semi-active control systems, a large number of academic publications have been presented. Semi-active control systems which are used the magnetic field controlled fluid have been shown significant improvements by the researchers. In the study, a design optimization method that has been carried out for the objectives of target damper force and maximum magnetic flux density of an MR damper has been presented. Finite element methods, electromagnetic analysis of magnetic field and CFD analysis of MR flow, have been used to obtain optimal value of design parameters. The new approach that is use of magnetic field and MR flow together and simultaneously has specified optimal design values. Two optimal design of MR damper obtained have been verified with experimental study by manufacturing and testing of the dampers.     

基于磁流变减震器的起落架着陆建模及仿真

磁流变减震器是一种半主动控制的阻尼装置,可显著改善起落架的减震效果。针对自行设计的多环形槽结构磁流变减震器,根据流变力学原理,建立了减震器力学模型,并据此建立基于Matlab的起落架系统动态力学模型。对于不同的机身质量和着陆垂直速度分量,得到励磁电流与振动幅值、频率及稳定时间等参数的关系。仿真结果表明,选用合适的励磁电流,可方便地控制振动参数,达到较理想的减震效果。     

Application of the “Contact Convoy” Concept to Hybrid Electric Vehicles

This paper applies an intelligent intervehicle device (termed a ldquobridging damperrdquo) to a convoy of in-contact vehicles. The field of application is backup for future automated highways and operation of novel guided systems using vehicle-following control. The vehicle represented in computer simulations is a parallel hybrid electric automobile. Using the advanced vehicle simulator (ADVISOR) model, the vehicle representation is tuned to achieve matching of the overall force and power characteristics and the same performance over an urban driving cycle. The model for which a dedicated Matlab Toolbox was constructed is described. Simulation results compare the vehicle-following control on its own with a passive damper and a ldquoquasi-activerdquo damper that is controlled in collaboration with the vehicle's drivetrain. Using transient disturbances in the form of wind gusts and short gradients, power peaks and longitudinal ride quality (vibration dose value) are used to evaluate the performance.     

Self-balancing based on Active Disturbance Rejection Controller for the Two-In-Wheeled Electric Vehicle,Experimental results

This article deals with a robust self-balancing control scheme for the Two-In-Wheeled Self-Balancing Electric-Vehicle (TIW-SB-EV). Due to time-varying and unknown torque load, uncertainties on system parameters, and the lack of knowledge of the friction components, the approach proposes the design and implementation of an active disturbance rejection control based on the extended state observer (ESO). The ESO is developed through the differentially Flatness property of the system. The system flat output measurement is obtained employing an absolute optical inclinometer, which represents the sole measurement of the plant. The electric traction for the TIW-SB-EV is composed of two In-wheel brushless DC motors (SG/F10-48 V, 800 W) powered by a controlled three-phase inverter. The TIW-SB-EV primary power source is supplied by two Lithium-Ion batteries (48 V, 10 AH). The proposed ADRC algorithm is coded on the TMS320F28335 Experimenter Kit, a device of the TMS320C28x/Delfino family. Real-time experimental results validate the mechanical design, electric drive, and control design and highlight the closed-loop robustness when the TIW-SB-EV is subjected to the endogenous and exogenous disturbances present in a real environment.     

SA9904B在电力参数远程测控系统中的应用

介绍Sames公司的三相功率/电量测量专用集成电路芯片(ASIC)SA990048的结构、功能及其串行通信接口的时序.介绍该芯片在电力参数远程测控系统中的应用.     

麦弗逊悬架在ADMS中嵌入遗传因子的优化研究

基于麦弗逊汽车悬架动力神经结构中的麦弗逊汽车悬架动力神经结构运动参数与数据优化瓶颈,利用基于麦弗逊汽车悬架动力神经结构空间结构和麦弗逊汽车悬架动力神经结构运动性能建立麦弗逊汽车悬架动力神经结构运动模型。同时利用数学运算数学运算几何定位节点的关联函数。同时利用汽车遗传因子方法进一步优化麦弗逊汽车悬架动力神经结构运动模型,并嵌入在Adams中。仿真实验表明：在Adams中嵌入汽车遗传因子后可有效控制定位节点的滑移量。所设计的ADAMS嵌入汽车遗传因子的优化设计方法,能够在汽车汽车悬架动力参数与数据优化时快速实现,证明了所建立模型的正确性和优化设计方法的有效性。     

小型无线场强探测传感器研究

近年来,微波加热因其高效性和清洁无污染等优点广泛应用于各个领域。然而,微波加热的不均匀性限制了微波作为高效加热能源的应用。通过测量和分析加热腔中的电场分布情况可以帮助设计人员改进微波加热腔体设计,提高微波加热的均匀性。现有的场强测量设备均为有线设备,应用场景极为有限。因此,本文提出了一种由探头、接收机和上位机三部分组成的无线场强探测传感器。介绍了无线场强探测传感器的结构和原理,采用横电磁波小室进行校准。通过一系列测量实验表明实测值与标准场强仪测量值一致性较好,可满足工程测量需求。     

Network architecture and communication modules for guaranteeing acceptable control and communication performance for networked multi-agent systems

When sensory and actuation devices in a control system are exchanging data through one common communication medium, the sharing of communication bandwidth will induce unavoidable data latency and might degrade the control performance. Hence, the utilization of communication resource and the requirement of control specification should be analyzed and properly designed when implementing a control system over a network architecture. In this paper, we analyze the performance of information sharing of multiple cooperative agents over one communication network, and propose design methodologies of guaranteeing acceptable control and communication performance in a networked control system. In particular, we study the relationship between the sampling rates of a control system,and the transmission rates of a communication network, and then utilize an integrated networked control design chart to help select design parameters and visualize overall system performance at different sampling and transmission rates. Based on the design parameters selected, the communication modules by utilizing deadband control and state estimation are presented for guaranteeing both control and communication performance. Simulation studies are conducted in a network-and-control simulation tool that is developed on the Matlab/Simulink platform and is used to demonstrate the proposed design methodologies. Both the analysis and simulation results illustrate the characteristics of designing mechanisms between control and communication performance and show the improvement of implementing the proposed communication modules.     

大型风机的高压变频调速系统的选型及其应用

生产企业中大型风机、泵类负载多为高压异步电机传动控制,恒速运转,其中绝大部分都运行在通过风门挡板或阀门调节流量的节流状态,能量损耗相当严重。本文通过对贵州—企业技术改造中成功地设计选型高压变频调速系统的介绍,对高压变频装置选型的主要技术参数和性能要求进行了阐述,对高压变频系统的构成、单元结构、控制方式等进行了介绍,分析...