Basic experiments on robot-base vibration control of the hot-line work robot system using genetic algorithm

Past studies on hot-line robot systems have focused on the execution of various hot-line works such as the cutout/connection of electric wires and replacement of insulators. Robot-base vibration control methods, however, have seldom been discussed [1–5]. The high-speed operation of the hot-line work robot system, Phase II, in tasks is being worked on with the goal of practical utilization in the near future. Speed increases in boom and manipulator movements are a key part of this. The Phase II system's boom has a natural frequency of 1.0 Hz in commonly used angles. If the boom or the manipulator is rapidly accelerated, the robot base vibrates violently, hampering task execution. This paper proposes a vibration control method, in which control gain and position command acceleration/deceleration time are optimized for the movement of the robot base. In conjunction with the vibration control, we also focus on the optimization for positioning accuracy and preventing overshoot of the manipulator. These three issues are simultaneously solved using the genetic algorithm. The proposed method has been determined for use in a preliminary experiment for the Phase II system development. A simplified test-bed manipulator of the two-axis horizontal scalar type was employed for simulation and experimentation in order to reduce modeling error. The initial effects brought about by the proposed method are verified. © 1998 Scripta Technica, Electr Eng Jpn, 123(2): 40–52, 1998     

Robust design of vibration suppression control system for crane using sway angle observer considering friction disturbance

It is desirable for a container crane to operate smoothly and quickly. For this purpose, the control system of a container crane should be capable of antisway control for suppressing vibrations. A vision sensor system is often used to detect the sway angle. However, since a control system with a vision sensor has a delay time when determining the angle, it sometimes leads to deterioration of control performance owing to the delay time. In order to overcome this problem, this paper proposes a new antisway crane control system based on a dual‐state observer with sensor‐delay correction. However, because of nonlinear friction in the crane, the estimation accuracy achieved by using the observer is poor. To overcome this problem, this paper proposes a disturbance observer considering friction disturbance. The control performance and e?ectiveness of the proposed robust control system based on the estimated information are shown to be satisfactory by experimental results. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(3): 36–46, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22412     

卫星姿控系统的滑模容错控制及主动振动抑制

针对执行机构故障情况下挠性卫星姿态控制系统的容错控制及主动振动抑制问题,建立轨控推力扰动条件下含执行器故障的挠性卫星姿态控制系统模型,采用自适应控制方法设计该姿控系统的高阶滑模容错控制器,并在姿态稳定的基础上设计基于高阶滑模的补偿项以降低挠性振动对姿态精确度的影响。对轨控期间飞轮正常情形及故障情形下的挠性卫星姿态仿真结果表明,在卫星姿态控制系统存在干扰的条件下,该方法能实现对执行器故障的容错能力并能提高姿态控制精确度。     

低频线振动台加速度失真非线性补偿控制方法

为了抑制低频线振动台中存在的模型不确定性及外部扰动,基于模糊基函数网络(FBFN)提出了一种自适应重复学习控制方法.利用FBFN逼近低频线振动台的模型不确定性及外部扰动,将对模型不确定性和扰动的辨识问题转化为对FBFN权系数的辨识问题.所提出的控制律由自适应控制和重复学习控制组成.自适应律用来估计FBFN权系数;为了有效地减弱抖振,使用自适应PI控制结构逼近非连续控制.由于非连续控制的界是未知的,利用自适应律估计这个未知的界.重复学习控制用来提高系统对周期性输入信号的跟踪性能.采用Lyapunov理论设计的自适应重复学习控制律保证了低频线振动台的渐近稳定性和位置跟踪性能.仿真结果表明,自适应重复学习控制律改善了系统的跟踪性能和加速度失真度.     

Centralized load control system demonstration test (interim report)

The maximum power peak has sharpened in recent years owing to the widespread use of air conditioners and other such equipment. Additionally, the gap between power demand during the day and night, as well as that among the seasons, is widening, while the annual load factor is on the decline. These factors prevent the effective use of generating facilities and are driving costs up. Countermeasures in the form of promotion of load leveling from the demand side have become a national priority. It was in these circumstances that the New Energy and Industrial Technology Development Organization (NEDO) officially requested that Kyushu Electric Power Co., Inc. (KEPCO) develop a load leveling technology for the future. For eight years starting in 1986, KEPCO conducted a demonstration test in which it directly controlled customer water heaters and air conditioners in a district of the city of Kagoshima. In addition, the company started a test in 1994 to demonstrate load leveling effects through indirect load control in a district of the city of Fukuoka. This load control involved providing customers on the demand side with their own load curves, electricity charge data, and other information so that they would themselves experiment with electricity use. This paper will outline the Centralized Load Control System demonstration test and discuss the system configuration and the 1996 test results of indirect load control that generated effects such as a peak reduction of 0.1 kW per household. © 1999 Scripta Technica, Electr Eng Jpn, 128(2): 7–17, 1999     

Sensorless suppression control for frame vibration of PMSM

It is well known that frame vibration occurs in driving permanent magnet synchronous motors (PMSM). The authors have suggested a method for suppression of frame vibration by means of Fourier series and repetitive control. The method requires an acceleration sensor and a position sensor. However, the use of such a sensor is not desirable from the point of view of system cost. Therefore, this paper proposes a method of sensorless suppression control of frame vibration. The effectiveness of the proposed method is illustrated by experiments. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(3): 53–61, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21048     

基于配变负荷测控系统的配电网络运行状态估计

在配电网中配变负荷测控系统的基础上,结合时间序列预测算法,以及平均功率系数,提出了一种对配电网运行状态进行估计的方法。通过实践证明应用此方法能较准确地得到配电网的运行状态数据。     

基于主动电磁控制的滑动轴承-转子系统自激振动抑制数值仿真

本文以滑动轴承支承的柔性转子系统为研究对象,仿真模拟实际机组高速旋转时滑动轴承-转子系统的自激振动情况。首先,基于有限元法建立单圆盘转子动力学模型,轴承非线性油膜力模型采用短轴承油膜力模型,主动电磁控制采用闭环控制策略,通过PID控制器参数得到其等效的刚度和阻尼;然后,采用四阶龙格-库塔法求解转子系统动力学模型,通过对转子施加主动电磁控制抑制其发生自激振动,对比分析转子升速过程中未采用主动电磁控制和采用主动电磁控制时轴承处的振动变化情况。仿真结果表明:未采用主动电磁控制时,自激振动发生在约2倍的一阶临界转速附近,而采用主动电磁控制不但降低了过临界时的振动幅值,还有效抑制了自激振动的发生。     

Critical load bus voltage control using DVR under system frequency variation

The paper discusses the voltage control of a critical load bus using a dynamic voltage restorer (DVR) in a distribution system. The critical load requires a balanced sinusoidal waveform across its terminals preferably at system nominal frequency of 50 Hz. It is assumed that the frequency of the supply voltage can vary and is different from the system nominal frequency. The DVR is operated such that it holds the voltage across the critical load bus terminals constant at system nominal frequency irrespective of the frequency of the source voltage. In case of a frequency mismatch, the total real power requirement of the critical load has to be supplied by the DVR. To compensate for frequency variation, the dc link of the DVR is supplied through an uncontrolled rectifier that provides a path for the real power required by the critical load to flow. A simple frequency estimation technique is discussed which uses a moving average process along with zero-crossing detector. Through detailed analysis and simulation studies using PSCAD/EMTDC it is shown that the voltage is completely controlled across the critical load.     

基于状态反馈附加阻尼控制的柔性直流电网抑制低频振荡

为了提升交直流互联系统的动态稳定性,研究了利用多端柔性直流输电系统阻尼交流系统低频振荡的方法。分析了柔性直流电网接入后系统的振荡模态,研究了直流电网对交流系统稳定性的影响,并基于全维状态空间反馈设计了柔性直流系统的附加阻尼控制器。系统振荡时该附加阻尼控制器能够输出附加控制量,调节各换流站的有功功率,从而抑制系统的振荡。以含有四端柔性直流电网的新英格兰10机系统为例进行了仿真研究,仿真结果表明,引入了该控制器的柔性直流电网能够很好地抑制原系统的低频振荡,改善系统的动态性能。     

Active vibration control of a motor system by using H∞ control theory

This paper considers the vibration control of a motor system which has a motor and a load connected with a flexible shaft. However, this system often generates a shaft torsional vibration. Traditional methods of treating this problem to adjust the PID controller so that the closed-loop frequency response is slower than that of the vibration mode. On the other hand, one method has already been proposed in which the vibration is suppressed by a disturbance observer. This paper proposes a new approach based on H_∞ control theory. For comparison, a PI control system based on classical control theory also is constructed. The results of several experiments show that compared with the PI control system, the H_∞ control system is effective in suppressing the vibration. Further, the H_∞ controller obtained in the study consists of a PI controller and a series compensator that functions as an active vibration controller.     

Realization of acceleration control using multirate sampling method

This paper focuses on the realization of high‐performance motion control based on acceleration control. The characteristics of acceleration control are investigated and the relationship between the performance and sampling frequency of the system is discussed. This paper then describes that a higher sampling frequency is required for acquisition of output information than for updating the input value. Based on this idea, a new multirate sampling method for an acceleration control system is proposed. A disturbance observer for the multirate system is designed by adopting a new definition of disturbance torque. A bilateral system is introduced as a preeminent example of a system that requires robust acceleration control. Both simulations and experiments are performed on the system, and the validity of the proposition is verified by the results. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(4): 72–81, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20507     

电力系统负荷预测的基本要求及基本原则

随着现代科学技术的快速发展,负荷预测技术的研究也在不断深化,但电力系统负荷预测的基本要求及基本原则却是不能忽视的重要方面,对电力系统负荷预测的基本要求及基本原则进行了详细论述.     

Robust analysis and design of power system load frequency control using the Kharitonov's theorem

This paper presents a robust decentralized proportional-integral (PI) control design as a solution of the load frequency control (LFC) in a multi-area power system. In the proposed methodology, the system robustness margin and transient performance are optimized simultaneously to achieve the optimum PI controller parameters. The Kharitonov’s theorem is used to determine the robustness margin, i.e., the maximal uncertainty bounds under which the stable performance of the power system is guaranteed. The integral time square error (ITSE) is applied to quantify the transient performance of the LFC system. In order to tune the PI gains, the control objective function is optimized using the genetic algorithm (GA). To validate the effectiveness of the proposed approach, some time based simulations are performed on a three-area power system and the results are then compared with an optimal PI controller. The comparisons show that the proposed control strategy provides the satisfactory robust performance for the wide range of system parameters and load changes in the presence of system nonlinearities and is superior to the other methods.     

Short-Span seeking control of hard disk drives with multirate vibration suppression perfect tracking control

In this paper, a novel vibration suppression perfect tracking control (PTC) method is proposed for short-span seeking mode of hard disk drives (HDDs) based on multirate feedforward control. In the proposed method, it is assumed that plant is modeled as the rigid-body and primary vibration modes. By using this model, a feedforward PTC is designed with a modified controllable canonical realization in order to control the transient response of position, velocity, acceleration, and jerk of the proposed virtual plant. Simulations and experiments are carried out to show that the proposed system can suppress the primary vibration mode in short-span seeking control. Finally, the proposed method is applied to a benchmark problem of HDD control which is made by a technical committee of IEE of Japan. The robustness of the proposed feedforward method is examined against the variation of primary vibration frequency. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Multi-substation control central load area forecasting by using HP-filter and double neural networks (HP-DNNs)

Electricity load demand forecasting of Thailand using Hodrick–Prescott (HP) filters and double-neural networks (DNNs) is presented in this article by dividing whole country area into multi-substation areas. The signals of load demand in each subarea will be decomposed to trend and cycling signals by HP-filter before sent to DNNs for load demand forecast. The trend signals show close relationship with economic affecting features, while the cycling signals demonstrate strong relationship with weather features. These obvious correlations will be used for feature input selections. In the finally stage, the forecasting results from each subarea will be composed for the whole country area result. Comparing to other forecasting models, this approach not only reduce complexity of the forecasting model but also decrease mean absolute percent error (MAPE) as 1.42%. Moreover, this method can be applied to other load forecasting in power system and any application that can be separated into subarea.     

挠性航天器姿态机动和振动抑制的自适应控制

针对挠性航天器姿态机动控制中存在的参数不确定性、外部干扰、挠性附件振动及挠性模态不易直接测量的问题,提出一种具有干扰抑制的自适应输出反馈机动控制器设计方法.设计中无需忽略挠性附件和中心刚体的耦合,利用挠性附件固有物理特性构造一种结构简单的开环模态观测器,然后用以此获得的模态估计信息及可测量的姿态四元数和角速度信息,基于...     

负荷管理控制系统实施技术

设计了具有分布式客户／服务器结构模式的控制中心，并根据楼房多用户的情况，设计了一种可采集上百路电度量的终端设备FRTU。FRTU由主控系统和子系统组成，主控系统完成常规远方终端的功能，子系统负地输入电能脉冲量的采集和处理工作。系统结构简单，方便适用。     

Optimal load frequency control through combined state and control gain estimation for noisy measurements

Combined estimation of state and feed-back gain for optimal load frequency control is proposed. Load frequency control (LFC) addresses the problem of controlling system frequency in response to disturbance, and is one of main research areas in power system operation. A well acknowledged solution to this problem is feedback stabilization, where the Linear Quadratic Regulator (LQR) based controller computes the feedback gain K from the known system parameters and implements the control, assuming the availability of all the state variables. However, this approach restricts control to cases where the state variables are readily available and the system parameters are steady. Alternatively, by estimating the states continuously from available measurements of some of the states, it can accommodate dynamic changes in the system parameters. The paper proposes the technique of augmenting the state variables with controller gains. This introduces a non-linearity to the augmented system and thereby the estimation is performed using an Extended Kalman Filter. This results in producing controller gains that are capable of controlling the system in response to changes in load demand, system parameter variation and measurement noise.