For physical ozone absorption without reaction,two parametric estimation methods,i.e.the common linear least square fitting and non-linear Simplex search methods,were applied,respectively,to determine the ozone mass t...For physical ozone absorption without reaction,two parametric estimation methods,i.e.the common linear least square fitting and non-linear Simplex search methods,were applied,respectively,to determine the ozone mass transfer coefficient during absorption and both methods give almost the same mass transfer coefficient.While for chemical absorption with ozone decomposition reaction,the common linear least square fitting method is not applicable for the evaluation of ozone mass transfer coefficient due to the difficulty of model linearization for describing ozone concentration dissolved in water.The nonlinear Simplex method obtains the mass transfer coefficient by minimizing the sum of the differences between the simulated and experimental ozone concentration during the whole absorption process,without the limitation of linear relationship between the dissolved ozone concentration and absorption time during the initial stage of absorption.Comparison of the ozone concentration profiles between the simulation and experimental data demonstrates that Simplex method may determine ozone mass transfer coefficient during absorption in an accurate and high efficiency way with wide applicability.展开更多
A PID parameters tuning and optimization method for a turbine engine based on the simplex search method was proposed. Taking time delay of combustion and actuator into account, a simulation model of a PID control syst...A PID parameters tuning and optimization method for a turbine engine based on the simplex search method was proposed. Taking time delay of combustion and actuator into account, a simulation model of a PID control system for a turbine engine was developed. A performance index based on the integral of absolute error （IAE） was given as an objective function of optimization. In order to avoid the sensitivity that resulted from the initial values of the simplex search method, the traditional Ziegler-Nichols method was used to tune PID parameters to obtain the initial values at first, then the simplex search method was applied to optimize PID parameters for the turbine engine. Simulation results indicate that the simplex search method is a reasonable and effective method for PID controller parameters tuning and optimization.展开更多
料筒温度是影响注塑成型产品质量的关键参数之一,比例积分微分(proportional integral differential,PID)控制器在料筒温度控制系统中广泛应用。然而,PID控制器参数优化依赖操作者经验,存在成本高、效率低、精度差的问题。为解决上述问...料筒温度是影响注塑成型产品质量的关键参数之一,比例积分微分(proportional integral differential,PID)控制器在料筒温度控制系统中广泛应用。然而,PID控制器参数优化依赖操作者经验,存在成本高、效率低、精度差的问题。为解决上述问题,围绕料筒温度PID控制器参数优化展开研究。首先,针对料筒温度控制系统性能优化,提出性能评价指标,设计PID控制器参数优化框架;然后,基于知识指引型数据驱动优化策略的思想,对单纯形搜索算法进行改进,提出了基于历史梯度近似的知识指引型单纯形搜索算法,以提高PID控制器参数优化效率。实验结果表明,与单纯形搜索算法相比,改进后的算法以牺牲少量优化精度为代价,显著提升了优化效率,降低了PID控制器参数优化成本。展开更多
基金Project(2011467001)supported by the Ministry of Environment Protection of ChinaProject(2010DFB94130)supported by the Ministry of Science and Technology of China
文摘For physical ozone absorption without reaction,two parametric estimation methods,i.e.the common linear least square fitting and non-linear Simplex search methods,were applied,respectively,to determine the ozone mass transfer coefficient during absorption and both methods give almost the same mass transfer coefficient.While for chemical absorption with ozone decomposition reaction,the common linear least square fitting method is not applicable for the evaluation of ozone mass transfer coefficient due to the difficulty of model linearization for describing ozone concentration dissolved in water.The nonlinear Simplex method obtains the mass transfer coefficient by minimizing the sum of the differences between the simulated and experimental ozone concentration during the whole absorption process,without the limitation of linear relationship between the dissolved ozone concentration and absorption time during the initial stage of absorption.Comparison of the ozone concentration profiles between the simulation and experimental data demonstrates that Simplex method may determine ozone mass transfer coefficient during absorption in an accurate and high efficiency way with wide applicability.
文摘A PID parameters tuning and optimization method for a turbine engine based on the simplex search method was proposed. Taking time delay of combustion and actuator into account, a simulation model of a PID control system for a turbine engine was developed. A performance index based on the integral of absolute error （IAE） was given as an objective function of optimization. In order to avoid the sensitivity that resulted from the initial values of the simplex search method, the traditional Ziegler-Nichols method was used to tune PID parameters to obtain the initial values at first, then the simplex search method was applied to optimize PID parameters for the turbine engine. Simulation results indicate that the simplex search method is a reasonable and effective method for PID controller parameters tuning and optimization.
文摘料筒温度是影响注塑成型产品质量的关键参数之一,比例积分微分(proportional integral differential,PID)控制器在料筒温度控制系统中广泛应用。然而,PID控制器参数优化依赖操作者经验,存在成本高、效率低、精度差的问题。为解决上述问题,围绕料筒温度PID控制器参数优化展开研究。首先,针对料筒温度控制系统性能优化,提出性能评价指标,设计PID控制器参数优化框架;然后,基于知识指引型数据驱动优化策略的思想,对单纯形搜索算法进行改进,提出了基于历史梯度近似的知识指引型单纯形搜索算法,以提高PID控制器参数优化效率。实验结果表明,与单纯形搜索算法相比,改进后的算法以牺牲少量优化精度为代价,显著提升了优化效率,降低了PID控制器参数优化成本。
