基于改进粒子群算法的柴油发电机自适应PID控制

对柴油发电机数字电子调速系统进行了研究;数字电子调速系统是运用闭环控制来实现柴油发电机的转速恒定,以确保供电频率的稳定;传统的柴油发电机组调速器中都是用经典PID控制算法,传统PID控制存在的主要问题其实就是PID参数的整定问题,因为一次性得到的PID参数很难保证其系统的控制效果始终处于最优化状态,因此在频率控制器中引入了基于改进粒子群算法的PID参数自整定方法,实时改变PID参数以保证通过控制取得优化控制效果;在执行器上采用了步进电机,使其调速性能有了很大的改进,成本降低;实验仿真表明,该调速系统动态特性较好,有较高的精度,不失为柴油机调速的一种新方法。     

Fuzzy理论在电子调速器中的应用研究

柴油机电子调速器一般采用PID控制方法,为了提高系统的调速性能,在系统过渡过程的不同阶段控制器应取不同的增益,即应实时校正PID的参数.在实际系统中,校正的方法可通过分析被控量的测量值然后查询校正表进行.但要获得一个精细合适的校正表.须通过大量实验,工作量很大,调整也很不方便.本文介绍如何利用Fuzzy理论对电子调速器PID控制的参数进行实时校准,使电子调速器的控制性能得到改善.     

柴油机的模糊PID调速控制策略研究

研究了一种基于模糊PID算法的柴油机调速控制策略。提出了一种模糊控制改进算法,对电子调速器PID参数按调速系统过渡过程进行在线实时模糊自整定。Matlab/Simulink仿真结果表明,该系统超调量控制效果明显得到改善,动、静态控制效果要好于常规PID控制,具有控制灵活、响应速度快和适应性强等优点。     

电子调速器系统的角位移传感器设计

介绍了柴油机电子调速器系统的控制方案,采用差动变压器工作原理,对角位移传感器进行了结构及信号调理电路设计。并通过角位移传感器与角位移电磁执行器匹配,电子调速器系统的内环和外环3个模拟实验,得到了角位移传感器最佳工作性能参数,证实了电子调速系统稳态和动态响应性能指标完全满足柴油机正常调速的要求。     

无线传感器和执行器网络控制系统设计与仿真

无线传感器和执行器网络通过无线网络(ZigBee)将传感器和执行器与控制器相连,完成分布式传感和执行任务。针对无线网络传输和被控对象延时的不良影响,首先详细介绍了基于TrueTime 2.0的无线网络控制系统在Windows 7和Matlab R2010b环境下的搭建,给出了系统的仿真模型。对控制器节点分别采用常规PID控制和模糊PID控制算法进行仿真研究。仿真结果表明,对于存在延时环节的无线网络控制系统,模糊PID控制可以取得较好的控制效果,系统鲁棒性较强。该研究对物联网智能家居系统的设计具有一定参考价值。     

柴油机调速系统的模糊自适应PID控制

提出了一种模糊自适应PID算法。利用模糊自适应PID算法对柴油机电子调速器PID参数按调速系统过渡过程进行模糊自整定。从仿真结果看调速性能有明显改善。     

柴油机调速系统的模糊自适应PID控制

提出了一种模糊自适应PID算法.利用模糊自适应PID算法对柴油机电子调速器PID参数按调速系统过渡过程进行模糊自整定.从仿真结果看调速性能有明显改善.     

便携式汽油发电机电子调速器设计

为提高便携式汽油发电机的调速性能,采用数字信号控制器dsPIC开发了一种电子调速器.该调速器能根据负载大小和汽油机实际转速对油门位置进行调节,通过PID算法实现对汽油机转速的闭环控制.介绍了系统的总体方案,并对硬件、软件设计作了具体论述.试验结果表明,该调速器的控制效果达到设计要求.     

柴油机电液调速系统控制的研究

车用柴油机电液调速系统的控制,具有非线性、时变、非稳定等特点,柴油机调速控制采用采用模糊自整定PID控制和采用传统PID控制两种控制算法,都难以达到满意的控制效果.本文采用非线性控制器来控制其效果非常明显.     

直流调速系统的模糊／PID控制器设计

本文采用模糊/PID控制策略对直流调速系统的转速环进行了设计,根据转速误差的阀值由模糊控制切换到PID控制,给出了模糊控制规则和PID控制器各参数确定的方法,并利用Matlab进行了仿真验证,结果表明模糊/PID控制器具有较好的控制性能。     

An optimal control method for applications using wireless sensor/actuator networks

The wireless sensor/actuator networks (WSANs) can be used for spatially distributed control systems. With smart sensors and actuators, the WSANs are able to not only sense the control system states and report measurements, but also perform control and actuation. This paper investigates WSANs on their ability of control. A centralized controller is introduced into WSANs to make up closed-loop control systems, in which control decisions are made based on global network-wide information. A model of the control and communication over WSANs is made theoretically, based on which we achieved an optimal control method. It is demonstrated by simulations that the control method proposed could stabilize the control system quickly.     

On‐off iterative adaptive controller for low‐power micro‐robotic step regulation

A novel model‐free iterative adaptive controller is presented for low‐power control of piezoelectric actuators. The controller uses simple adaptation rules based on known general behavior of piezoelectric actuators to adjust on‐off switching times to drive piezoelectric actuators through a desired transient step motion. Adaptation rules are based on small numbers of measurements taken during each iteration of the actuator movement. Combined with the use of only on‐off control inputs, controller implementation can be possible at much lower overall power levels than would be needed to implement a conventional control strategy such as through pulse‐width‐modulation (PWM) with real‐time feedback. Such power savings are particularly important for the intended controller application to piezoelectric microactuators driving autonomous terrestrial micro‐robots. A method for predicting convergence of systems with nominally linear dynamics and unknown, bounded nonlinearities is described, and applied to a sample target piezoelectric actuator. The controller is tested in simulation and experimentally on a piezoelectric cantilever actuator, and shows predicted convergence to the desired response. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

带有稀疏执行器故障的事件触发网络化系统容错控制

针对一类具有事件触发信息传输机制的网络化控制系统,对系统故障执行器个数进行稀疏约束,研究系统在有限个执行器失效情况下的指数稳定及控制器设计问题。将系统故障执行器个数的约束转化为对控制器增益矩阵行的势约束,利用混合整数方法来解决这类稀疏约束的容错控制问题。在此基础上,利用Lyapunov泛函方法,得出闭环系统在有限个执行器失效情况下系统呈指数稳定的充分条件以及具有行稀疏约束的控制器设计方法。最后,通过一个飞行控制系统的数值仿真实例验证所提控制方法的可行性和有效性。     

Reconfigurable control of piecewise affine systems with actuator and sensor faults: Stability and tracking

A reconfigurable control approach for continuous-time piecewise affine (PWA) systems subject to actuator and sensor faults is presented. The approach extends the concept of virtual actuators and virtual sensors from linear to PWA systems on the basis of the fault-hiding principle that provides the underlying conceptual idea: the fault is hidden from the nominal controller and the fault effects are compensated. Sufficient linear matrix inequality (LMI) conditions for the existence of virtual actuators and virtual sensors are given that guarantee the recovery of closed-loop stability and the tracking of constant reference inputs. Since LMIs are efficiently solvable, this solution leads to a tractable computational algorithm that solves the reconfiguration problem. The approach is proven to be robust against model uncertainties and inaccurate fault diagnosis, and is evaluated using an example system of interconnected tanks.     

An adaptive integral sliding mode FTC scheme for dissimilar redundant actuation system of civil aircraft

ABSTRACT

This paper proposed a new adaptive integral sliding mode FTC scheme to deal with the actuator faults and failure. The scheme combines integral sliding mode control, control allocation scheme and adaptive strategy. The unknown actuator faults are handled by adaptive modulation gain of nonlinear ISMC law. To cope with complete failure, control allocation scheme is integrated with the baseline controller to provide tolerance. The proposed strategy relies on the estimate of actuator effectiveness. Therefore, an adaptive sliding mode observer based fault reconstruction scheme is proposed in this paper. The proposed scheme is implemented on dissimilar redundant actuation system driven by hydraulic and electro-hydraulic actuators. In nominal and faulty conditions, both actuators are contributing to achieving the desired control surface deflection. However, when the actuator failure occurs, the control signals are reallocated to the redundant actuator. The problem of dynamics mismatch is addressed using fractional order controller designed in an inner loop. The comparison with the existing literature is also conducted in the simulation to validate the dominant performance.     

A novel levitation control strategy for a class of redundant actuation maglev system

In most maglev (magnetic levitation) systems, redundant electromagnetic actuators are usually used to increase the stability and robustness of the levitation motion. However, the obvious interactions generate between the redundant actuators and other general electromagnetic actuators. In this paper, a new and efficient redundant levitation control strategy is developed to overcome the interactions in this maglev system. In the strategy, some separate general controllers are designed for all general actuators, and then some special controllers are used to real-time track the electromagnetic forces of all general actuators, and accordingly they create control signal for the redundant actuators to counteract the interactions among general actuators and redundant actuators. To further illustrate the strategy, a novel redundant actuation maglev system is then demonstrated, and a simplified expression of the redundant control strategy is investigated for the maglev system. The experimental results show that the redundant levitation controller successfully removes the interactions between redundant actuator and general actuators, and the redundant levitation controller maintains good robustness under disturbance.     

Stability and stabilization of linear sampled-data systems with multi-rate samplers and time driven zero order holds

In multi-rate sampled-data systems, a continuous-time plant is controlled by a discrete-time controller which is located in the feedback loop between sensors with different sampling rates and actuators with different refresh rates. The main contribution of this paper is to propose sufficient Krasovskii-based stability and stabilization criteria for linear sampled-data systems, with multi-rate samplers and time driven zero order holds. For stability analysis, it is assumed that an exponentially stabilizing controller is already designed in continuous-time and is implemented as a discrete-time controller. For each sensor (or actuator), the problem of finding an upper bound on the lowest sampling frequency (or refresh rate) that guarantees exponential stability is cast as an optimization problem in terms of linear matrix inequalities (LMIs). Furthermore, sufficient conditions for controller synthesis are formulated as LMIs. It is shown through examples that choosing the right sensors (or actuators) with adequate sampling frequencies (or refresh rates) has a considerable impact on stability of the closed-loop system.     

Adaptive actuator failure compensation for nonlinear MIMO systems with an aircraft control application

A direct adaptive approach is developed for control of a class of multi-input multi-output (MIMO) nonlinear systems in the presence of uncertain failures of redundant actuators. An adaptive failure compensation controller is designed which is capable of accommodating uncertainties in actuator failure time instants, values and patterns. A realistic situation is studied with fixed grouping of actuators and proportional actuation within actuator groups. The adaptive control system is analyzed, to show its desired stability and asymptotic tracking properties in the presence of actuator failure uncertainties. As an application, such an adaptive controller is used for actuator failure compensation of a twin otter aircraft longitudinal model, with design conditions verified and control structure and adaptive laws developed for a nonlinear aircraft dynamic model. The effectiveness of adaptive failure compensation is demonstrated by simulation results.     

基于观测器的移动执行器对二维分布参数系统的控制

研究二维分布参数系统在传感器执行器网络下的控制问题.传感器执行器网络由二维平面上固定的传感器与移动的执行器组成.首先,利用传感器对二维分布参数系统的测量信息设计观测器,用来估计二维分布参数系统的状态,并在观测器的基础上给出相应的控制器;然后,利用算子半群理论并结合Lyapunov方法,得到平面上移动的执行器的水平运动速度和垂直运动速度,该速度依赖于观测器的信息;最后,数值仿真表明,二维分布参数系统在该移动执行器控制下的性能得到了有效的提高.     

Optimal controller location in wireless networked control systems

The control performance of wireless networked control systems (WNCS) has been shown to heavily depend on the packet delivery quality of both the sensor‐to‐controller and controller‐to‐actuator communications. Such quality relies on the relative distance between the wireless transmitter and receiver, which naturally raises the challenging problem of controller placement in WNCS for optimal control performance. In this paper, we investigate the optimal controller location (OCL) problem in WNCS based on linear‐quadratic‐Gaussian control strategy. For the one‐hop network case where the controller can only be placed at either the sensor side or the actuator side, we derive a simple yet effective criterion to determine the OCL. For the more general multi‐hop case where the controller can be located at either one of the sensors, relays, or actuators, we obtain the necessary and sufficient condition under which the closed‐loop system is guaranteed to be stable. On the basis of these results, we further transform the OCL problem into an optimization problem that can be solved efficiently. Numerical results are provided to verify our analysis. Copyright © 2013 John Wiley & Sons, Ltd.