Robust control of variable speed autonomous underwater vehicle

Set point tracking control of autonomous underwater vehicle (AUV) via robust model predictive control (RMPC) is considered. Input-constrained RMPC with integral action, which has been developed in our previous work, is used to control the AUV in this study. In order to derive a RMPC control rule, non-linear dynamics of AUV with six degree of freedom is linearized at certain operating points. So, horizontal and vertical plane dynamics of system are represented by linear models which have polytopic uncertainties. Since the derived control rule will be used in real time, the computation time should be reduced. To overcome this computational time problem and get rid of trial–error step of Algorithm 1, a new algorithm is proposed here. The simulations are carried out using the control rule based on this algorithm and these results are presented.     

Simultaneous closed-loop tuning of cascade controllers based directly on set-point step-response data

This study presents a novel closed-loop tuning method for cascade control systems, in which both primary and secondary controllers are tuned simultaneously by directly using set-point step-response data without resorting to process models. The tuning method can be applied on-line to improve the performance of existing underperforming cascade controllers by retuning controller parameters, using routine operating data. The goal of the proposed design is to obtain the parameters of two proportional-integral-derivative (PID)-type controllers, so that the resulting inner and outer loops behave as similarly as possible to the appropriately specified reference models. The tuning rule and optimization problem related to the proposed design are derived. Based on the rationale behind cascade control, the secondary controller is designed based on disturbance rejection to quickly attenuate disturbances. The primary controller is designed to accurately account for the inner-loop dynamics, without requiring an additional test. In addition, robustness considerations are included in the proposed tuning method, which enable the designer to explicitly address the trade-off between performance and robustness for inner and outer loops independently. Simulation examples show that the proposed method exhibits superior control performance compared with the previous (model-based) tuning methods, confirming the effectiveness of this novel tuning method for cascade control systems.     

基于全网能量均衡的WirelessHART图路由算法

如何均衡使用网络节点能量并生成高可靠路由是WirelessHART网络研究的一个难题,为此提出了一种GRAEB（graph routing algorithm based on energy balancing）图路由算法。首先,网络被初始化为连通的图结构,能够提高丰富的冗余路径。网络管理器根据全网节点剩余能量、通信周期、链路分布等因子生成节点鲁棒系数矩阵,节点通过比较邻居的鲁棒系数来选择最优路径。另外,规定了邻居节点数的上限阈值,每次路由更新只保留鲁棒系数最优的邻居。仿真结果表明GRAEB不仅提高了网络可靠性,而且延长了网络寿命。     

基于80 C196KC单片机的Smith伺服控制器

讨论全数字伺服系统中的时间滞后，通过Smith预估控制器补偿系统中的时间滞后，提出一种应用80C196KC单片机的宽范围、高精度调速的控制方案及算法。对于非滞后系统采用Smith伺服控制器，可以简化系统、提高性能指标。     

仪表联锁一体化控制单元(ITCC)在压缩机防喘振控制上的应用

介绍了基于PLC的压缩机一体化控制系统,PLC和现场总线系统(DCS)、安全仪表系统(SIS)、马达一体化控制系统(MCC)等信号之间的相互关系。主要论述了压缩机的防喘振控制理论,防喘振控制器的功能及防喘振控制在赛科乙烯装置裂解气压缩机的应用。     

序贯抗差估计在旋转调制陀螺寻北中的应用

基于序贯抗差估计方法针对简化了的旋转调制陀螺寻北仪输出信号进行了寻北仿真研究.介绍了该型寻北仪的基本原理,在经典充贯平差的基础上,结合抗差M估计的原理,得到了序贯抗差估计的计算流程与公式.将寻北仪输出信号划分为2个阶段,对上述方法进行了仿真应用.仿真结果表明：通过该算法所得寻北结果误差均值与标准差均优于其它算法.     

PLC在电石加料装置中的应用

介绍了乙炔站电石加料装置的工艺特点,采用PLC技术,提高了电石加料装置的自动化控制水平,稳定了生产。     

RECURSIVE GENERALIZED M ESTIMATES FOR AUTOREGRESSIVE MOVING-AVERAGE MODELS

Abstract. Outliers in time series seriously affect conventional parameter estimates. In this paper a robust recursive estimation procedure for the parameters of auto-regressve moving-average models with additive outliers is proposed. Using 'cleaned' residuals from an initial robust fit of an autoregression of high order as input, bounded influence regression is applied recursively. The proposal follows certain ideas of Hannan and Rissanen, who suggested a three-stage procedure for order and parameter estimation in a conventional setting.
A Monte Carlo study is performed to investigate the robustness properties of the proposed class of estimates and to compare them with various other suggestions, including least squares, M estimates, residual autocovariance and truncated residual autocovariance estimates. The results show that the recursive generalized M estimates compare favourably with them. Finally, possible modifications to master even vigourous situations are suggested.     

鲁棒性项目调度中缓冲设置方法

研究应对不确定因素的鲁棒性项目调度, 针对其所用时间缓冲区技术中的两种重要方法——集中缓冲和STC (starting time criticality) 分散缓冲, 采用仿真模拟实验, 以项目管理库中的帕特森例1 为对象, 进行详细的比较研究. 研究结果表明, 分散缓冲法具有更好的解鲁棒性; 当活动时间的不确定性程度较大时, 集中缓冲法的质量鲁棒性较好; 当项目工期较紧时, 分散缓冲法具有更好的鲁棒性. 这些研究结论为管理者在特定的项目环境下选择合适的缓冲方法提供了决策依据.     

自控系统在加氢反应工艺中的应用

通过对化工生产中加氢反应的危险性简要介绍,并以某药厂对加氢反应工艺自控系统改造时从自控方案选择到自控参量、主要自控设施确定及安装、校验和系统调试等主要过程实施为例,说明此种危险可行性,为药厂类加氢工艺自控系统的技术改造提供相应的参考。