It is well-known that the IMC-PID controller tuning gives fast and improved set point response but slow disturbance rejection. A modification has been proposed in IMC-PID tuning rule for the improved disturbance rejec...It is well-known that the IMC-PID controller tuning gives fast and improved set point response but slow disturbance rejection. A modification has been proposed in IMC-PID tuning rule for the improved disturbance rejection. For the modified IMC-PID tuning rule, a method has been developed to obtain the IMC-PID setting in closed-loop mode without acquiring detailed information of the process. The proposed method is based on the closed-loop step set point experiment using a proportional only controller with gain K_(c0). It is the direct approach to find the PID controller setting similar to classical Ziegler-Nichols closed-loop method. Based on simulations of a wide range of first-order with delay processes, a simple correlation has been derived to obtain the modified IMC-PID controller settings from closed-loop experiment. In this method, controller gain is a function of the overshoot obtained in the closed loop set point experiment. The integral and derivative time is mainly a function of the time to reach the first peak(overshoot). Simulation has been conducted for the broad class of processes and the controllers were tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison. The PID controller settings obtained in the proposed tuning method show better performance and robustness with other two-step tuning methods for the broad class of processes. It has also been applied to temperature control loop in distillation column model. The result has been compared to the open loop tuning method where it gives robust and fast response.展开更多
BV500型可控震源振动器在川渝地区作业过程中,由于平板设计不合理,导致振动能量下传率低、激发信号畸变严重。因此,引入连续体拓扑优化方法,采用固体各向同性材料惩罚(Solid Istropic Material with Penalization,SIMP)模型变密度法,从...BV500型可控震源振动器在川渝地区作业过程中,由于平板设计不合理,导致振动能量下传率低、激发信号畸变严重。因此,引入连续体拓扑优化方法,采用固体各向同性材料惩罚(Solid Istropic Material with Penalization,SIMP)模型变密度法,从降低质量和增加刚度两个方面对BV500型可控震源振动器平板进行优化设计,创新研制了一种“八边形工字钢-20a”平板。优化后平板质量减轻了45.29%,平板刚度提升了79.92%,并开展了优化前后平板激振性能研究。仿真研究结果表明,与原铝合金整体平板相比,“八边形工字钢-20a”平板的能量下传率提高了15.11%,地表接触中心点位移振幅增大了43.74%,互作用力振幅提升了40.56%。现场实验表明,“八边形工字钢-20a”平板激振时,检波器近场信号平均振动速度有效值提升了22.23%,检波器远场信号平均振动速度有效值提升了39%,规律与可控震源道路激振数值仿真模拟结论一致。“八边形工字钢-20a”平板激振性能优于原铝合金整体平板,有效改善了BV500型可控震源在川渝地区道路激振效果。展开更多
基金the support provided by King Abdulaziz City for Science and Technology (KACST) through the Science & Technology Unit at King Fahd University of PetroleumMinerals (KFUPM) for funding this work through project number 11-ENE1643-04 as part of the Notional Science Technology and Innovation Plan
文摘It is well-known that the IMC-PID controller tuning gives fast and improved set point response but slow disturbance rejection. A modification has been proposed in IMC-PID tuning rule for the improved disturbance rejection. For the modified IMC-PID tuning rule, a method has been developed to obtain the IMC-PID setting in closed-loop mode without acquiring detailed information of the process. The proposed method is based on the closed-loop step set point experiment using a proportional only controller with gain K_(c0). It is the direct approach to find the PID controller setting similar to classical Ziegler-Nichols closed-loop method. Based on simulations of a wide range of first-order with delay processes, a simple correlation has been derived to obtain the modified IMC-PID controller settings from closed-loop experiment. In this method, controller gain is a function of the overshoot obtained in the closed loop set point experiment. The integral and derivative time is mainly a function of the time to reach the first peak(overshoot). Simulation has been conducted for the broad class of processes and the controllers were tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison. The PID controller settings obtained in the proposed tuning method show better performance and robustness with other two-step tuning methods for the broad class of processes. It has also been applied to temperature control loop in distillation column model. The result has been compared to the open loop tuning method where it gives robust and fast response.
文摘为提高建筑结构的抗震性能,解决传统被动式调谐质量阻尼器(tuned mass damper,TMD)减振频带窄且自身频率难以调节的缺点,基于由形状记忆合金(shape memory alloy,SMA)材料制成的SMA弹簧,提出了一种具有调频能力的新型TMD(shape memory alloy tuned mass damper,SMA-TMD)。通过频率测试试验发现,SMA-TMD的频率会随着通入SMA弹簧电流的增大而升高。通过设计并开展振动台试验,验证SMA-TMD在调频与减振性能方面的可行性与有效性。试验结果表明,与失谐的传统TMD相比,通过调节输入电流而与主体结构再次调谐的SMA-TMD,在控制结构顶层峰值加速度响应方面,能够展现出更高的减振率,减振性能至少可提升21.5%。此外,SMA-TMD的工作行程相比于传统TMD也有显著改善,前后2组试验工况下的最大工作行程分别至少能够降低46.9%、39.2%。这不仅能够节省装置的安装空间,预留更多的建筑面积,还可拓宽装置的应用场景,使其能够布置在一些具有空间局限性的结构中。
文摘BV500型可控震源振动器在川渝地区作业过程中,由于平板设计不合理,导致振动能量下传率低、激发信号畸变严重。因此,引入连续体拓扑优化方法,采用固体各向同性材料惩罚(Solid Istropic Material with Penalization,SIMP)模型变密度法,从降低质量和增加刚度两个方面对BV500型可控震源振动器平板进行优化设计,创新研制了一种“八边形工字钢-20a”平板。优化后平板质量减轻了45.29%,平板刚度提升了79.92%,并开展了优化前后平板激振性能研究。仿真研究结果表明,与原铝合金整体平板相比,“八边形工字钢-20a”平板的能量下传率提高了15.11%,地表接触中心点位移振幅增大了43.74%,互作用力振幅提升了40.56%。现场实验表明,“八边形工字钢-20a”平板激振时,检波器近场信号平均振动速度有效值提升了22.23%,检波器远场信号平均振动速度有效值提升了39%,规律与可控震源道路激振数值仿真模拟结论一致。“八边形工字钢-20a”平板激振性能优于原铝合金整体平板,有效改善了BV500型可控震源在川渝地区道路激振效果。
