基于改进PID控制器的EHA液压系统建模和控制研究

电动静液执行器(electro-hydrostatic actuator,EHA)系统是一种高能量密度的执行器单元,集成伺服电机、液压泵、蓄液池和油箱于一体。为使EHA在快速响应状态有更高的执行效率,需要对液压系统各单元的参数作用进行研究。本研究提出了一种新的EHA液压系统设计方法。通过结合双向液压齿轮泵的死区效应,以及各部件的实验结果和理论公式对EHA液压系统进行数学建模。在此基础上结合ISIDF技术对PID控制器进行修正。结果表明改进后的PID可以实现更加精确的控制效果,将EHA系统的位置控制性能提高两倍。     

热电厂DCS系统基于GE Fanuc公司90-30系列可编程序控制器的CPU冗余设计实现

热电厂DCS系统CPU采用热备冗余方式。双CPU运行时,处于热备状态的控制单元仅仅接收上位机和I/O站送来的信息,它不执行控制任务,也不干预主控制单元的运行,一旦主控制单元出现故障,则热备控制单元自动代替主控单元承担控制任务,使整个系统的控制流程不会发生停顿,实现无扰切换。采用热备冗余方式,系统的可靠性得到了保证,平均无故障时间得到了延长。     

热电厂DCS系统基于GE Fanuc公司90-30系列可编程序控制器的CPU冗余设计实现

热电厂DCS系统CPU采用热备冗余方式。双CPU运行时，处于热备状态的控制单元仅仅接收上位机和I／O站送来的信息，它不执行控制任务，也不干预主控制单元的运行，一旦主控制单元出现故障，则热备控制单元自动代替主控单元承担控制任务，使整个系统的控制流程不会发生停顿，实现无扰切换。采用热备冗余方式，系统的可靠性得到了保证，平均无故障时间得到了延长。     

基于人体位置检测的商场智能照明研究

本文在智能照明的基本理论与方法的基础上,提出了一种新的控制方法,对于商场无自然照明区域和智能照明系统的“夜间”工作状态做出了改进,提出了以检测人体位置来实现照度按区域变化的新方法。在节约用电的基础上产生良好的照明效果。     

网络化控制系统随机时延的补偿研究

在网络化控制系统中引入离散隐马尔可夫模型,建立网络状态与控制器-执行器时延之间的概率模型.网络化控制系统被建模成一个马尔可夫跳变线性系统,并预测出当前采样周期内的控制器-执行器时延.使用该预测值设计一个状态反馈控制器,实现对控制器-执行器时延的补偿.对比仿真实验验证了所提方法的优越性.     

浅谈建筑电气照明节能设计

该文提出了电气节能设计中照明节能设计的必要性,并从照明节能设计方案、充分利用自然光、照明系统的控制和管理这几个方面来阐述如何实现照明节能设计.     

腐蚀环境作业用机器人钯镍电镀系统电机控制技术

腐蚀环境作业用机器人钯镍电镀系统的电机优化控制可以提高电镀加工的精确度,提出一种基于自适应PID神经网络模糊控制算法的腐蚀环境作业用机器人钯镍电镀系统电机控制技术。首先进行了控制系统的总体设计和构成描述,电机控制系统主要是由感知系统、驱动器和执行器系统等单元组成;然后采用自适应PID神经网络模糊控制算法进行控制器改进设计,提高稳定性,降低控制误差。仿真结果表明,该控制方法性能较好,鲁棒性和控制品质较高。     

基于MODIBUS总线协议的小型水电站远程监控系统

本文概述了一种基于MODIBUS总线协议的小型水电站远程监控系统,包括：多个现场控制单元,各控制单元通过MODIBUS总线与远方集中控制中心的用于实时监测、控制各现场控制单元的业务运行状态的工控计算机相连。现场控制单元包括：输入模块、处理模块、输出模块、执行模块和现场控制屏。本文将水轮机控制功能、闸门启闭控制功能和辅机控制等多种功能集成在同一组PLC设备上,按内嵌程序,同时自动处理水电站自动控制的多个业务需求,有效简化了系统结构、缩减设备规模和成本,增强了PLC设备的通用性和可靠性。     

住宅Wi-Fi智能照明控制系统设计

提出一种基于Wi-Fi的住宅智能照明控制系统解决方案,从智能化、人性化设计的角度为住宅照明控制系统的设计提供一种参考。以STM8S103系列单片机作为核心控制单元,通过Wi-Fi模块实现与手机APP客户端的通信,结合APP实现使用手机控制不同房间灯具亮灭以及调节亮度和色彩等功能。本系统还可以兼容室内其他具有Wi-Fi接口的智能设备,共同构成综合的智能家居控制系统。     

西门子S7-200PLC直接控制电动执行机构

对计算机控制系统中电动执行器控制展开优化探究,分析传统D/A转换器结合伺服放大器存在的问题,提出了消除中间环节,直接通过PLC控制电动执行器的方法,通过应用发现控制精度显著提升。     

Trajectory tracking control for unmanned surface vessel with input saturation and disturbances via robust state error IDA-PBC approach

A novel robust state error Interconnection and Damping assignment Passivity-based Control (IDA-PBC) controller for Unmanned Surface Vessels (USVs) with input saturation and disturbances is proposed. A reduced-order extended state observer, the state error IDA-PBC technique, and an auxiliary dynamic system are used in the controller design. Firstly, a reduced-order extended state observer is constructed to estimate the external disturbances. Then, the state error IDA-PBC approach reduces system energy consumption and is easy to implement. We construct an auxiliary dynamic system to handle input saturation. All signals of the whole system can guarantee uniformly ultimate boundedness. Simulations demonstrate the robustness and effectiveness of the proposed approach.     

Robust input/output model matching of asynchronous sequential machines under intermittent actuator faults

A robust model matching control scheme for input/output asynchronous sequential machines (ASMs) with intermittent actuator faults is presented in the framework of corrective control. In our problem setting, certain actuator outputs are not transmitted to the machine temporarily owing to random faults. We first present a state observer that predicts the current stable state of the machine based on the output burst and control input, as well as diagnoses actuator faults. We then address the existence condition and design procedure for an output-feedback corrective controller that matches the input/output behavior of the closed-loop system to that of a reference model against intermittent loss of actuator outputs. To demonstrate the applicability of the proposed control method, we implement a practical asynchronous digital system with the developed corrective controller on the field-programmable gate array (FPGA) circuit. Experimental verifications using the FPGA circuit are also provided.     

Design of observer-based feedback control for time-delay systems with application to automotive powertrain control

A new approach for observer-based feedback control of time-delay systems is developed. Time-delays in systems lead to characteristic equations of infinite dimension, making the systems difficult to control with classical control methods. In this paper, a recently developed approach, based on the Lambert W function, is used to address this difficulty by designing an observer-based state feedback controller via assignment of eigenvalues. The designed observer provides estimation of the state, which converges asymptotically to the actual state, and is then used for state feedback control. The feedback controller and the observer take simple linear forms and, thus, are easy to implement when compared to nonlinear methods. This new approach is applied, for illustration, to the control of a diesel engine to achieve improvement in fuel efficiency and reduction in emissions. The simulation results show excellent closed-loop performance.     

某型抗干扰电台灵敏度检测方案设计

灵敏度是电台的重要指标,随着通信技术的发展,采用跳频和扩频技术的抗干扰电台越来越多地应用到现代超短波通信系统中。由于跳频图案和扩频编码对于用户是不可知的,那么抗干扰电台灵敏度的检测难以实施。本文通过设计通信控制器,运用同型号电台相互通信的方法,并采用内嵌式计算机系统完成调制音频数据产生、信噪比和误码率分析、收发状态转换等功能,来实施音频灵敏度和数据灵敏度的检测。实际检测结果证明,这种方法能够实现未知跳频图案和扩频码情况下电台灵敏度的自动检测,提高了抗干扰电台检测水平。     

Quadrotor stabilization under time and space constraints using implicit PID controller

In this paper, the quadrotor stabilization under time and state constraints is studied. The objective is to design a nonlinear controller under time and state constraint for quadrotor. The nonlinear quadrotor model is built by the Euler-Lagrange approach while ignoring the Coriolis terms, hub moment and force. Based on quadrotor’s dynamic model, a nonlinear feedback controller is designed for the quadrotor stabilization under time and state constraints. This feedback is an implicit PID controller where the feedback gains are obtained from LMIs (Linear matrix inequalities). LMI system characterizing the system stability and convergence properties is built based on convex embedding approach and implicit Lyapunov function method. To demonstrate the application prospects of implicit PID controller, robustness analysis is provided to show the property of implicit PID controller under external disturbance. The key novelty of this paper is that the implicit PID controller is proven feasible for applying to the quadrotor under time and state constraints, which is also the main outcome.     

A new robust fault-tolerant controller for self-repairing flight control system

A new robust fault-tolerant controller scheme integrating a main controller and a compensator for the self-repairing flight control system is discussed. The main controller is designed for high performance of the original faultless system. The compensating controller can be seen as a standalone loop added to the system to compensate the effects of fault guaranteeing the stability of the system. A design method is proposed using nonlinear dynamic inverse control as the main controller and nonlinear extended state observer-based compensator. System robustness is greatly improved by using the new configuration controller. The stability of the whole closed-loop system is analyzed. Feasibility and validity of the new controller is demonstrated with an aircraft simulation example.     

Maximal perturbation bounds for robust stabilizability of fractional-order systems with norm bounded perturbations

This paper investigates the maximal perturbation bound problem for robust stabilizability of the fractional-order system with two-norm bounded perturbations or infinity-norm bounded perturbations. Firstly, a necessary condition and several sufficient conditions for robust stabilization are derived. Secondly, linear matrix inequality approaches for computing the maximal robust stabilizability perturbation bound of such perturbed fractional-order system with a linear state feedback controller, simultaneously obtaining the corresponding linear state feedback stabilizing controller are presented. With the help of the linear matrix inequality solvers, we can easily obtain the maximal robust stabilizability perturbation bound and the corresponding linear state feedback stabilizing controller. Finally, simulation examples are given to demonstrate the effectiveness of the proposed approaches.     

Robust observer-based fault estimation and accommodation of discrete-time piecewise linear systems

In this paper a new integrated observer-based fault estimation and accommodation strategy for discrete-time piecewise linear (PWL) systems subject to actuator faults is proposed. A robust estimator is designed to simultaneously estimate the state of the system and the actuator fault. Then, the estimate of fault is used to compensate for the effect of the fault. By using the estimate of fault and the states, a fault tolerant controller using a PWL state feedback is designed. The observer-based fault-tolerant controller is obtained by the interconnection of the estimator and the state feedback controller. We show that separate design of the state feedback and the estimator results in the stability of the overall closed-loop system. In addition, the input-to-state stability (ISS) gain for the closed-loop system is obtained and a procedure for minimizing it is given. All of the design conditions are formulated in terms of linear matrix inequalities (LMI) which can be solved efficiently. Also, performance of the estimator and the state feedback controller are minimized by solving convex optimization problems. The efficiency of the method is demonstrated by means of a numerical example.     

Robust simultaneous fault detection and control for a class of nonlinear stochastic switched delay systems under asynchronous switching

This paper concerns the simultaneous fault detection and control (SFDC) problem for a class of nonlinear stochastic switched systems with time-varying state delay and parameter uncertainties. The switching signal of detector/controller unit (DCU) is assumed to be with switching delay, which results in the asynchronous switching between the subsystems and DCU. By constructing a switching strategy depending on the state and switching delays, new sufficient conditions expressed by a set of linear matrix inequalities (LMIs) is derived to design DCU gains. This problem is formulated as an H_∞ optimization problem and both mean square exponential stability and fault detection of augmented system are considered. A numerical example is finally exploited to verify the effectiveness and potential of the achieved scheme.