To track the rapidly changing temperature profiles of thermal cycling of polymerase chain reaction （PCR） accurately, an innovative feedforward variable structural proportional-integral-derivative （FVSPID） controll...To track the rapidly changing temperature profiles of thermal cycling of polymerase chain reaction （PCR） accurately, an innovative feedforward variable structural proportional-integral-derivative （FVSPID） controller was developed. Based on the step response test data of the heat block, a reduced first order model was estabfished at different operating points. Based on the reduced model, the FVSPID controller combined a feedforward path with the variable structural proportional-integral-derivative （PID） control. The modified feedforward action provided directly the optimal predictive power for the desired setpoint to speed up the dynamic response. To cooperate with the feedforward action, a variable structural PID was applied, where the P mode was used in the case of the largest errors to speed up response, whereas the PD mode was used in the case of larger errors to suppress overshoot, and finally the PID mode was applied for small error conditions to eliminate the steady state offset. Experimental results illustrated that compared to the conventional PID controller, the FVSPID controller can not only reduce the time taken to complete a standard PCR protocol, but also improve the accuracy of gene amplification.展开更多
A new cascade control program was proposed based on modified internal model control to handle stable,unstable and integrating processes with time delay.The program had totally four controllers of which the secondary l...A new cascade control program was proposed based on modified internal model control to handle stable,unstable and integrating processes with time delay.The program had totally four controllers of which the secondary loop had two controllers and the primary loop had two controllers.The two secondary loop controllers were designed using IMC technique.They were decoupled completely and could be adjusted independently,which avoided the undesirable influence on performance of the primary controllers.The main controller in the primary loop was devised as a PID using the method of minimum sensitivity,which could guarantee not only the nominal performance but also the robust stability of the system.A setpoint filter was added in the primary loop to improve the tracking performance.All the controllers of the two closed-loops were designed analytically,and could be adjusted and optimized by single parameter respectively.Simulations were carried out on three various processes with time delay,and the results show that the proposed method can provide a better performance of both set-point tracking and disturbance rejection and robustness against parameters perturbation.展开更多
文摘针对人工跛行检测不够及时,难以发现突发中、重度跛行及轻度跛行行为的问题,该文提出了一种基于正态分布背景统计模型(normal background statistical model,NBSM)与局部循环中心补偿跟踪模型(local circulation center compensation track,LCCCT)和线性斜率最近邻分类(distilling data of KNN,DSKNN)技术的奶牛跛行检测方法。首先利用NBSM模型对奶牛序列图像中的目标奶牛像素区域进行分割,然后对得到的奶牛像素区域利用LCCCT模型提取目标奶牛身体前部像素区域,用其区域通过DSKNN模型提取目标奶牛的头部、颈部以及与颈连接的背部轮廓线拟合直线斜率数据,基于大样本视频序列帧数据将视频集制成轻度跛行、中重度跛行及正常等3类标签的斜率数据集。为了验证算法的有效性,对随机选取的18段奶牛视频进行了验证,其中正常奶牛、轻度跛行奶牛及中重跛行奶牛视频段各6段,获得头部、颈部及背部连接处的拟合直线斜率数据集。在未清洗的数据集上,分别利用SVM、Naive Bayes以及KNN分类算法进行了奶牛跛行的分类检测试验,试验结果表明,SVM与Naive Bayes跛行分类检测正确率均为82.78%,KNN奶牛跛行检测正确率为81.67%。将未清洗的数据集进行清洗后,3类算法的结果表明,KNN分类算法的跛行检测正确率达93.89%,高于SVM分类算法的91.11%及Naive Bayes分类算法的86.11%。上述结果表明通过头部、颈部及背部连接处的拟合直线斜率特性可以正确检测奶牛跛行,未清洗的数据经数据清洗后,KNN分类算法可以取得更好的检测结果。该研究结果对于奶牛跛行疾病的预防、诊断具有重要意义。
基金Supported by the National Natural Science Foundation of China (No.60574038) and the Open Project Program of the State KeyLaboratory of Bioreactor Engineering/ECUST.
文摘To track the rapidly changing temperature profiles of thermal cycling of polymerase chain reaction （PCR） accurately, an innovative feedforward variable structural proportional-integral-derivative （FVSPID） controller was developed. Based on the step response test data of the heat block, a reduced first order model was estabfished at different operating points. Based on the reduced model, the FVSPID controller combined a feedforward path with the variable structural proportional-integral-derivative （PID） control. The modified feedforward action provided directly the optimal predictive power for the desired setpoint to speed up the dynamic response. To cooperate with the feedforward action, a variable structural PID was applied, where the P mode was used in the case of the largest errors to speed up response, whereas the PD mode was used in the case of larger errors to suppress overshoot, and finally the PID mode was applied for small error conditions to eliminate the steady state offset. Experimental results illustrated that compared to the conventional PID controller, the FVSPID controller can not only reduce the time taken to complete a standard PCR protocol, but also improve the accuracy of gene amplification.
基金Project(J11LG02) supported by the Science and Technology Funds of Education Department of Shandong Province,China
文摘A new cascade control program was proposed based on modified internal model control to handle stable,unstable and integrating processes with time delay.The program had totally four controllers of which the secondary loop had two controllers and the primary loop had two controllers.The two secondary loop controllers were designed using IMC technique.They were decoupled completely and could be adjusted independently,which avoided the undesirable influence on performance of the primary controllers.The main controller in the primary loop was devised as a PID using the method of minimum sensitivity,which could guarantee not only the nominal performance but also the robust stability of the system.A setpoint filter was added in the primary loop to improve the tracking performance.All the controllers of the two closed-loops were designed analytically,and could be adjusted and optimized by single parameter respectively.Simulations were carried out on three various processes with time delay,and the results show that the proposed method can provide a better performance of both set-point tracking and disturbance rejection and robustness against parameters perturbation.
