网络环境下不敏感系统的分布式区域预测控制方法

针对二分图网络结构下的不敏感系统的可控性比较差的问题,本文提出了带有区域控制的分布式模型预测控制方法.该方法首先利用分支定界法对分布式控制系统结构进行最优设计;然后,结合区域控制提高控制系统的动态性能指标;最后,依据回路之间的关联性的强弱选择每个回路的控制方式(精确控制或区域控制).仿真结果显示带有区域控制的分布式预测控制系统的调节时间比没有带区域控制的分布式控制系统明显缩短;同时,通过对回路控制方式的选择增加了精确控制的智能体数量.仿真结果证明了利用分布式区域预测控制方法可以提高系统的容错性,通过对系统的可控性和关联性进行分析,可以在精确控制和区域控制之间寻找到最优组合,从而达到快速精确的控制效果.     

基于BPPID的疏浚管道稳定流速控制

针对疏浚船管道输送过程中泥浆管道流速难以控制,容易造成较大的功耗、磨损甚至会堵管、爆管等风险,本文以疏浚泥泵管道输送实验台为研究对象,提出一种基于BP神经网络的PID控制器,对管道输送流速进行稳定控制。在采用系统辨识方法对实验台进行建模的基础上,将BPPID与传统PID控制器进行仿真对比分析并利用模型实验台分别进行了流速阶跃变化和流速跟踪实验。实验结果表明BPPID控制对突变工况具有自适应自学习能力,为实际挖泥船输泥管道的稳定流速提供借鉴。     

使用黄金分割法的管道压力系统自适应控制

压力是工业过程控制常用参数,为了探索黄金分割自适应控制在工业过程控制中的应用技术,本文将其应用于水流管道的压力控制.利用控制实验平台,搭建了以变频调速驱动水泵的压力控制实验系统.阐述了特征建模与黄金分割自适应控制对该系统的适用性和稳定性,并通过分析确定了特征模型类型和控制算法.考虑到时延的影响,采用数字外推预测算法对管道压力误差进行处理.对控制方案进行了仿真分析,完成了与黄金分割自适应控制相关的管道压力控制实验.实验结果表明,黄金分割自适应控制能够实现管道压力的高精度控制,现场调试简单,该控制方案的优越性得到了验证.     

一种系统化流水线控制方法

本文研究设计了一种系统化流水线控制方法及其递推理论公式。基于该方法,在0.18um CMOS工艺条件下,实现系统时钟为200MHz的兼容于ARMv4指令集微处理器,指令执行效率最低为150 MIPS。每一级流水线本质为本级流水线是否保存指令执行结果、本级流水线指令是否执行下一级流水线、是否自锁执行本级流水线。根据这一本质,只需单独考虑每一类指令的执行过程,而无需考虑指令之间的复杂关系,使系统设计简单化,其优点在于对流水线深度不敏感,控制结构类似,适合于高深度、最优深度流水线设计,解决流水线控制逻辑的设计难度,提高微处理器指令执行效率。     

基于神经网络PID的疏浚管道泥浆流速控制

疏浚作业中，泥浆管道内物料的组成、粒径、浓度等随水下地形土质等变化很大，易造成流速波动甚至堵管、爆管等故障，因此泥浆流速稳定控制对泥浆输送的效率和安全具有重要意义；疏浚管道输送系统具有非线性、大时滞和参数时变等特征，传统PID控制方法效果不佳，故此将BP神经网络和传统PID控制算法相结合，并将其应用于泥浆流速控制中。以河海大学管道输送实验平台为对象，采用受控自回归CAR模型描述泥泵变频器频率与管道泥浆流速之间的关系，通过实验和数值处理对模型进行离线辨识；在此基础上通过仿真对比传统PID、单神经元PID和BP-PID的流速控制性能，发现BP-PID控制器的超调量仅为3.8%，响应时间为11s，控制性能较好；最后通过在体积浓度~10%到~30%泥浆范围内，泥浆浓度小幅度和大幅度增减实验，对流速控制方法进行了验证，结果表明在浓度平缓或剧烈波动时，采用BP-PID控制算法的流速控制系统，均能够在保证输送安全的前提下，快速、稳定地达到目标流速，具有较好的自适应控制性能。     

挖泥船泥浆管道输送流速的自适应预估控制

针对挖泥船泥浆管道输送流速控制的大惯性、大时滞、参数时变和建模困难等特点, 提出一种单神经元自适应预估控制方案. 该方案利用神经网络的自学习能力, 对系统结构、参数、不确定性和非线性进行学习, 结合Marsik和Strejc提出的无辨识自适应控制算法对控制参数进行在线修正, 在控制方案中加入Smith预估器, 利用搜索寻优的方法对时变的时滞进行在线优化, 提高了预估算法的鲁棒性和适应能力. 通过现场实验证明了本控制方法的有效性, 在疏浚施工环境变化, 时滞较大的条件下仍然能够使泥浆流速基本保持稳定, 具有     

使用形式化验证方法进行流水线验证

随着流水线技术的广泛应用,流水线设计的验证问题也越来越受到业界的关注.本文提出的方法作为自上而下验证方法的一部分,可以在指令级对流水线设计的正确性进行检验.本文从控制逻辑的角度对流水线的行为进行分析,通过为控制逻辑建立FSM表示,以及采用NuSMV作为验证工具,达到对流水线的自动验证.这种方法的优势在于是以流水段为单位进行检验,这种局部验证的方法不但可以降低建模和检验的复杂度,还可以极大地缩短验证时间.     

环境试验室热工系统规则自提取模糊控制仿真

以某环境试验室室内温度、送风系统和热水系统多回路在线控制为背景, 针对其存在的多参数、大滞后、非线性等控制难题, 讨论了各个回路热工特性传递函数建立和自组织模糊控制仿真问题. 首先, 提出了规则自提取模糊控制(self-abstracting rules fuzzy control, SARFC)方法. 然后, 根据各被控回路的动态热工特性和参数辨识要求, 试验研究了各回路的动态响应特性, 完成了各回路传递函数模型参数的辨识, 得到了各回路的传递函数模型. 最后, 采用SARFC方法, 仿真研究了基于送风系统调节和热水系统调节的环境试验室温度模糊控制仿真, 得到了较好的控制仿真效果, 为进一步试验研究环境试验室热工系统模糊控制提供了理论基础.     

基于扰动补偿的多源受扰系统反步控制设计

针对一类多源受扰系统的跟踪控制问题, 提出基于降阶广义扩张状态观测器(ROGESO)的指令滤波反步控制设计方法. 首先, 将各通道中的总扰动分别作为扩展状态变量, 通过构造ROGESO对其进行同步实时估计. 在此基础上, 利用反步法递归设计虚拟控制律, 实现各级子系统的镇定, 并将各通道的扰动估计值反馈至对应子系统的虚拟控制律中进行反向补偿, 提高系统的扰动抑制性能, 保证系统输出对参考输入信号的高精度跟踪. 然后, 应用Lyapunov函数分析闭环系统的稳定性. 最后, 通过数值仿真验证所提方法的有效性.     

Flocking control of a fleet of unmanned aerial vehicles

Current applications using single unmanned vehicle have been gradually extended to multiple ones due to their increased efficiency in mission accomplishment, expanded coverage areas and ranges, as well as enhanced system reliability. This paper presents a flocking control method with application to a fleet of unmanned quadrotor helicopters (UQHs). Three critical characteristics of formation keeping, collision avoidance, and velocity matching have been taken into account in the algorithm development to make it capable of accomplishing the desired objectives (like forest/pipeline surveillance) by safely and efficiently operating a group of UQHs. To achieve these, three layered system design philosophy is considered in this study. The first layer is the flocking controller which is designed based on the kinematics of UQH. The modified Cucker and Smale model is used for guaranteeing the convergence of UQHs to flocking, while a repelling force between each two UQHs is also added for ensuring a specified safety distance. The second layer is the motion controller which is devised based on the kinetics of UQH by employing the augmented state-feedback control approach to greatly minimize the steady-state error. The last layer is the UQH system along with its actuators. Two primary contributions have been made in this work: first, different from most of the existing works conducted on agents with double integrator dynamics, a new flocking control algorithm has been designed and implemented on a group of UQHs with nonlinear dynamics. Furthermore, the constraint of fixed neighbouring distance in formation has been relaxed expecting to significantly reduce the complexity caused by the increase of agents number and provide more flexibility to the formation control. Extensive numerical simulations on a group of UQH nonlinear models have been carried out to verify the effectiveness of the proposed method.     

SCADA系统在长输原油管道上的应用

以洪荆、钟荆原油管道SCADA系统为例,阐述了该系统的架构、通讯设计、SCADA系统功能等。长输原油管道采用密闭输送工艺,其自动控制系统为SCADA系统,实现在调度中心对全线进行监控、调度和管理,沿线各个工艺站场达到无人操作,有人值守。介绍了洪荆、钟荆原油管线的工艺流程和主要设备,并详细描述了SCADA系统的硬件、软件配置,以及所实现的功能。     

Performance analysis of a new energy-efficient variable supply pressure electro-hydraulic motion control method

Electro-hydraulic actuation is used in many motion control applications due to its high power density, excellent dynamic response and good durability. However fluid power actuation has been shown to be very energy inefficient, with an average efficiency for fluid power systems across all industries of 22% in the USA. This is a very significant problem, given that 3% of the energy used by mankind is transmitted in this way.The key challenge for researchers is to reduce energy losses in hydraulic actuation systems without increasing weight, size, and noise, and without reducing speed of response. Conventional high performance electro-hydraulic motion control systems use a fixed supply pressure with valve-controlled actuators (FPVC). This is inherently inefficient due to the need to use a valve to throttle the flow required by each actuator in the system down to match its load pressure. In this paper, a new load-prediction based method is proposed, in which the supply pressure is varied to track the pressure required by any actuator branch. By implementing this model-based approach using a high response servomotor-driven pump, it is shown that the dynamic response remains excellent. The load model not only allows feedforward control for servomotor speed based on the motion demand, but also feedforward for the control valves to supplement conventional proportional-integral feedback control.The new variable supply pressure valve-controlled (VPVC) method is investigated in simulation and experimentally using a two-axis hydraulic robot arm supplied by an axial piston pump. The performance has been rigorously compared with the same robot arm using a fixed supply pressure and proportional-integral joint position control. Experimental results showed that up to 70% hydraulic power saving was achieved, and that the dynamic tracking errors for VPVC were about half that for FPVC as a result of using feedforward control.     

Adaptive control Lyapunov function based model predictive control for continuous nonlinear systems

A design of adaptive model predictive control (MPC) based on adaptive control Lyapunov function (aCLF) is proposed in this article for nonlinear continuous systems with part of its dynamics being unknown at the starting time. Specifically, to guarantee the convergence of the closed-loop system with online predictive model updating, a stability constraint is designed. It limits the aCLF of the system under the MPC to be less than that under an online updated auxiliary adaptive control. The auxiliary adaptive control which implements in a sampling-hold fashion can guarantee the convergence of the controlled system. The sufficient conditions that guarantee the states to be steered to a small region near the equilibrium by the proposed MPC are provided. The calculation of the proposed algorithm does not depend on the model mismatch at the starting time. And it does not require the Lyapunov function of the state of the real system always to be reduced at each time. These provide the potential to improve the performance of the closed-loop system. The effectiveness of the proposed method is illustrated through a chemical process example.     

Adaptive control and constrained control allocation for overactuated ocean surface vessels

In this article, the constrained control allocation is proposed for overactuated ocean surface vessels with parametric uncertainties and unknown external disturbances. The constrained control allocation is transformed into a convex quadratic programming problem and a recurrent neural network is employed to solve it. To complete the control allocation, the control command is derived via the backstepping method. Adaptive tracking control is proposed for the full-state feedback case using the backstepping technique and the Lyapunov synthesis. It is proved that the proposed adaptive tracking control is able to guarantee semi-global uniform ultimate boundedness of all signals in the closed-loop system. Then, the obtained control command is distributed to each actuator of overactuated ocean vessels. Finally, simulation studies are presented to illustrate the effectiveness of the proposed adaptive tracking control and the constrained control allocation scheme.     

主干道动态协调控制方法研究

针对干线交通双向绿波协调控制中的相位冲突问题,提出了一种主干道动态协调控制方法。根据交通路口关联度计算方法将主干道划分为若干个控制子区;根据划分好的控制子区,计算出控制子区控制参数和控制子区间的协调控制参数：其中,针对我国城市交通流特点,对韦伯斯特周期公式进行修正,并设计了一种支路相位排前可行度函数用于各个路口相序进行优化,依此根据一段时间内的交通流信息计算出所有控制参数,包括公共信号周期,各路口的绿信比,各路口的相序以及所有路段的引导车速。仿真结果表明,该方法比分散控制能有效地提高主干道的行车速度,能够有效降低干线的通行时间。     

A time-optimal control algorithm for digital computer control

A time-optimal control algorithm for digital computer control allowing bounds on control variables and state variables is presented. Through linear programming techniques a time-optimal sequence is computed by using a linear discrete model of the process. For real-time applications feedback control is achieved by recalculating the control sequence each sampling period. In addition, an adaptive control strategy based on on-line estimation of the state variables and the parameters of the system is introduced. In order to be able to apply the algorithm in a real-time environment, computational efficiency is emphasized. An application of the algorithm to a sixth-order multivariable system is given.     

窗口流量控制的干线动态协调控制方法

城市交通干线在高峰时期经常处于饱和状态,排队车辆溢出至上游交叉口的"死锁"现象时有发生.为避免干线阻塞、提高饱和条件下干线交通流的运行效率,首先提出一种有效带宽评价方法对已有干线绿波协调控制系统的运行状态及控制效果进行监控;其次借鉴TCP/IP窗口流量控制思想,设计一种窗口流量控制的干线动态协调控制方法,控制城市干线拥挤交通流.模拟试验及对比结果表明,通过窗口流量通告的方式,下游交叉口可以向上游交叉口实时告知路段的有效容量,便于各交叉口信号机根据当前的交通需求及路段的有效容量重新分配各股车流的绿灯时间.     

史密斯预估PID控制在I/A''s集散控制系统上的应用

分布式集散系统DCS的普及与提高为先进控制的应用提供了强有力的硬件和软件平台。针对EFPT-IB复杂多容对象的加热炉出口温度大纯后特性,介绍了在I/A’series集散控制系统上利用其接口函数进行史密斯（SMITH）预估PID控制算法研究,通过在EFPT系统上的应用,取得了很好的控制效果。     

Optimal Valve Closure Operations for Pressure Suppression in Fluid Transport Pipelines

When a valve is suddenly closed in fluid transport pipelines, a pressure surge or shock is created along the pipeline due to the momentum change. This phenomenon, called hydraulic shock, can cause major damage to the pipelines. In this paper, we introduce a hyperbolic partial differential equation (PDE) system to describe the fluid flow in the pipeline and propose an optimal boundary control problem for pressure suppression during the valve closure. The boundary control in this system is related to the valve actuation located at the pipeline terminus through a valve closing model. To solve this optimal boundary control problem, we use the method of lines and orthogonal collocation to obtain a spatial-temporal discretization model based on the original pipeline transmission PDE system. Then, the optimal boundary control problem is reduced to a nonlinear programming (NLP) problem that can be solved using nonlinear optimization techniques such as sequential quadratic programming (SQP). Finally, we conclude the paper with simulation results demonstrating that the full parameterization (FP) method eliminates pressure shock effectively and costs less computation time compared with the control vector parameterization (CVP) method.