Essentially, it is significant to supply the consumer with reliable and sufficient power. Since, power quality is measured by the consistency in frequency and power flow between control areas. Thus, in a power system ...Essentially, it is significant to supply the consumer with reliable and sufficient power. Since, power quality is measured by the consistency in frequency and power flow between control areas. Thus, in a power system operation and control,automatic generation control(AGC) plays a crucial role. In this paper, multi-area(Five areas: area 1, area 2, area 3, area 4 and area 5) reheat thermal power systems are considered with proportional-integral-derivative(PID) controller as a supplementary controller. Each area in the investigated power system is equipped with appropriate governor unit, turbine with reheater unit, generator and speed regulator unit. The PID controller parameters are optimized by considering nature bio-inspired firefly algorithm(FFA). The experimental results demonstrated the comparison of the proposed system performance(FFA-PID)with optimized PID controller based genetic algorithm(GAPID) and particle swarm optimization(PSO) technique(PSOPID) for the same investigated power system. The results proved the efficiency of employing the integral time absolute error(ITAE) cost function with one percent step load perturbation(1 % SLP) in area 1. The proposed system based FFA achieved the least settling time compared to using the GA or the PSO algorithms, while, it attained good results with respect to the peak overshoot/undershoot. In addition, the FFA performance is improved with the increased number of iterations which outperformed the other optimization algorithms based controller.展开更多
为提高井下作业质量,实现对钻机在工作中转速的精确、高效控制,以某煤矿工程为例,开展其井下作业过程自动化钻机钻速模糊比例-积分-微分(Proportion Integral Differential,PID)自适应控制方法的设计研究。根据钻机的动力系统,建立钻机...为提高井下作业质量,实现对钻机在工作中转速的精确、高效控制,以某煤矿工程为例,开展其井下作业过程自动化钻机钻速模糊比例-积分-微分(Proportion Integral Differential,PID)自适应控制方法的设计研究。根据钻机的动力系统,建立钻机动力函数,计算钻机推力,建立煤矿井下自动化钻机数学模型。将输入变量(转速误差、误差变化率)精确值转换为模糊集合的隶属度,设计基于模糊PID的钻机转速输入控制。在钻机上安装多种传感器,实时监测钻机的各项工作参数,利用模糊PID控制器,进行自动化钻机转速的自适应调节。对比实验结果表明:设计的方法可以实现对钻机转速的快速、准确控制,保证钻进速度的稳定性。展开更多
在当前的电气应用中,变频器控制系统应用广泛,但面临的挑战也愈发明显。特别是在能耗管理方面,由于其缺乏智能调控频段能耗的能力,系统整体能耗偏高。为此,文章提出基于自适应比例-积分-微分(Proportional Integral Derivative,PID)算...在当前的电气应用中,变频器控制系统应用广泛,但面临的挑战也愈发明显。特别是在能耗管理方面,由于其缺乏智能调控频段能耗的能力,系统整体能耗偏高。为此,文章提出基于自适应比例-积分-微分(Proportional Integral Derivative,PID)算法的变频器节能控制系统设计。构建以微处理器为核心的变频器节能控制结构,将神经网络与PID控制器相结合,构造自适应PID控制器。结合变频器节能控制结构的能耗计算与反馈,通过自适应调节权值系数完成变频系数调整,降低各频段能耗,实现变频器节能控制研究。实验结果显示,该系统节能效果显著,能耗最高仅为20 J,且相较于对比文献,该系统运行稳定,运行时间短,为变频器节能控制运行提供了保障。展开更多
针对常规比例、积分和微分(proportional integral derivative,PID)控制器在无人艇航向控制系统中表现出的稳定性差、控制精度低等问题,文章提出一种将模糊控制与反向传播(back propagation,BP)神经网络相结合的控制算法;在MATLAB中对...针对常规比例、积分和微分(proportional integral derivative,PID)控制器在无人艇航向控制系统中表现出的稳定性差、控制精度低等问题,文章提出一种将模糊控制与反向传播(back propagation,BP)神经网络相结合的控制算法;在MATLAB中对比常规PID控制器、模糊PID控制器与模糊神经网络PID控制器在给定期望航向角下的航向控制性能,仿真结果表明模糊神经网络PID控制器对无人艇的航向控制性能最佳;在搭建的实验平台上对不同航向控制器下无人艇的航行轨迹和航向角进行比较,实验结果进一步验证了模糊神经网络PID航向控制算法的优越性。展开更多
在传统比例积分微分(Proportional Integral Derivative,PID)控制的基础上,考虑到论域因子的误差,设计了一种函数型的变论域模糊PID控制策略。基于1/4车辆二自由度磁流变半主动悬架系统,首先,建立了磁流变阻尼器的正、逆模型;然后,根据...在传统比例积分微分(Proportional Integral Derivative,PID)控制的基础上,考虑到论域因子的误差,设计了一种函数型的变论域模糊PID控制策略。基于1/4车辆二自由度磁流变半主动悬架系统,首先,建立了磁流变阻尼器的正、逆模型;然后,根据车辆磁流变半主动悬架系统的振动特性建立了模糊推理规则;最后,基于变论域的思想,设计了模糊论域的伸缩因子,以获得最优的控制精度。利用Matlab/Simulink软件在随机路面和正弦路面分别对车辆磁流变半主动悬架进行了仿真分析,通过车身垂直加速度、悬架动挠度以及车轮动载荷进行悬架性能评价,结果表明,与被动悬架、模糊控制和模糊PID控制相比,变论域模糊PID控制使车辆磁流变半主动悬架各性能指标均得到有效改善。展开更多
Asymmetric stereoscopic video coding can take advantage of binocular suppression in human vision by representing one of the two views in lower quality.This paper proposes a bit allocation strategy for asymmetric stere...Asymmetric stereoscopic video coding can take advantage of binocular suppression in human vision by representing one of the two views in lower quality.This paper proposes a bit allocation strategy for asymmetric stereoscopic video coding.In order to improve the accuracy of bit allocation and rate control in the left view,a proportionalintegral-derivative controller is adopted.Meanwhile,to control the quality fluctuation between consecutive frames of the left view,a quality controller is adopted.Besides,a fuzzy controller is proposed to control the variation in quality between the left and right views by comparing the PSNR disparity of two views with a fixed threshold,which is used to quantize the binocular psycho-visual redundancy and adjust the quantization parameter (QP) of the right view correspondingly.The proposed algorithm has been implemented in H.264/AVC video codec,and the experimental results show its effectiveness in rate control while keeping a good quality for the left view,and fewer bits are allocated for the right view so that the overall bit rate is saved by 7.2% at most without the loss of subjective visual quality for stereoscopic video.展开更多
自动驾驶智能汽车逐渐普及,其在通过城市路面的沟渠、井盖和减速带等特殊路面时,制动与减速时的稳定性与乘坐舒适性较差,为改善这一状况,对悬架的设计提出了更高的要求。为了提高自动驾驶智能汽车制动与减速时的稳定性,通过融合比例积...自动驾驶智能汽车逐渐普及,其在通过城市路面的沟渠、井盖和减速带等特殊路面时,制动与减速时的稳定性与乘坐舒适性较差,为改善这一状况,对悬架的设计提出了更高的要求。为了提高自动驾驶智能汽车制动与减速时的稳定性,通过融合比例积分微分(Proportional Integral Derivative,PID)与模糊算法,设计了针对这些特殊路面的主动悬架模糊PID控制器,在Matlab/Simulink软件中搭建了半车主动悬架仿真模型,通过惯性测量单元(Inertial Measurement Unit,IMU)实车测量了沟渠路面的路面激励信息,并完成仿真试验。结果表明,当自动驾驶智能汽车在C级路面和沟渠路面行驶时,设计的主动悬架模糊PID控制器较单一算法的控制器更有效地降低了车身垂向加速度、车身俯仰角加速度、车轮动载荷和悬架动行程,改善了悬架性能。展开更多
文摘Essentially, it is significant to supply the consumer with reliable and sufficient power. Since, power quality is measured by the consistency in frequency and power flow between control areas. Thus, in a power system operation and control,automatic generation control(AGC) plays a crucial role. In this paper, multi-area(Five areas: area 1, area 2, area 3, area 4 and area 5) reheat thermal power systems are considered with proportional-integral-derivative(PID) controller as a supplementary controller. Each area in the investigated power system is equipped with appropriate governor unit, turbine with reheater unit, generator and speed regulator unit. The PID controller parameters are optimized by considering nature bio-inspired firefly algorithm(FFA). The experimental results demonstrated the comparison of the proposed system performance(FFA-PID)with optimized PID controller based genetic algorithm(GAPID) and particle swarm optimization(PSO) technique(PSOPID) for the same investigated power system. The results proved the efficiency of employing the integral time absolute error(ITAE) cost function with one percent step load perturbation(1 % SLP) in area 1. The proposed system based FFA achieved the least settling time compared to using the GA or the PSO algorithms, while, it attained good results with respect to the peak overshoot/undershoot. In addition, the FFA performance is improved with the increased number of iterations which outperformed the other optimization algorithms based controller.
文摘为提高井下作业质量,实现对钻机在工作中转速的精确、高效控制,以某煤矿工程为例,开展其井下作业过程自动化钻机钻速模糊比例-积分-微分(Proportion Integral Differential,PID)自适应控制方法的设计研究。根据钻机的动力系统,建立钻机动力函数,计算钻机推力,建立煤矿井下自动化钻机数学模型。将输入变量(转速误差、误差变化率)精确值转换为模糊集合的隶属度,设计基于模糊PID的钻机转速输入控制。在钻机上安装多种传感器,实时监测钻机的各项工作参数,利用模糊PID控制器,进行自动化钻机转速的自适应调节。对比实验结果表明:设计的方法可以实现对钻机转速的快速、准确控制,保证钻进速度的稳定性。
文摘在当前的电气应用中,变频器控制系统应用广泛,但面临的挑战也愈发明显。特别是在能耗管理方面,由于其缺乏智能调控频段能耗的能力,系统整体能耗偏高。为此,文章提出基于自适应比例-积分-微分(Proportional Integral Derivative,PID)算法的变频器节能控制系统设计。构建以微处理器为核心的变频器节能控制结构,将神经网络与PID控制器相结合,构造自适应PID控制器。结合变频器节能控制结构的能耗计算与反馈,通过自适应调节权值系数完成变频系数调整,降低各频段能耗,实现变频器节能控制研究。实验结果显示,该系统节能效果显著,能耗最高仅为20 J,且相较于对比文献,该系统运行稳定,运行时间短,为变频器节能控制运行提供了保障。
文摘针对常规比例、积分和微分(proportional integral derivative,PID)控制器在无人艇航向控制系统中表现出的稳定性差、控制精度低等问题,文章提出一种将模糊控制与反向传播(back propagation,BP)神经网络相结合的控制算法;在MATLAB中对比常规PID控制器、模糊PID控制器与模糊神经网络PID控制器在给定期望航向角下的航向控制性能,仿真结果表明模糊神经网络PID控制器对无人艇的航向控制性能最佳;在搭建的实验平台上对不同航向控制器下无人艇的航行轨迹和航向角进行比较,实验结果进一步验证了模糊神经网络PID航向控制算法的优越性。
文摘在传统比例积分微分(Proportional Integral Derivative,PID)控制的基础上,考虑到论域因子的误差,设计了一种函数型的变论域模糊PID控制策略。基于1/4车辆二自由度磁流变半主动悬架系统,首先,建立了磁流变阻尼器的正、逆模型;然后,根据车辆磁流变半主动悬架系统的振动特性建立了模糊推理规则;最后,基于变论域的思想,设计了模糊论域的伸缩因子,以获得最优的控制精度。利用Matlab/Simulink软件在随机路面和正弦路面分别对车辆磁流变半主动悬架进行了仿真分析,通过车身垂直加速度、悬架动挠度以及车轮动载荷进行悬架性能评价,结果表明,与被动悬架、模糊控制和模糊PID控制相比,变论域模糊PID控制使车辆磁流变半主动悬架各性能指标均得到有效改善。
基金Supported by National Natural Science Foundation of China(No.60972054)National High Technology Research and Development Program of China("863"Program,No.2009AA011507)
文摘Asymmetric stereoscopic video coding can take advantage of binocular suppression in human vision by representing one of the two views in lower quality.This paper proposes a bit allocation strategy for asymmetric stereoscopic video coding.In order to improve the accuracy of bit allocation and rate control in the left view,a proportionalintegral-derivative controller is adopted.Meanwhile,to control the quality fluctuation between consecutive frames of the left view,a quality controller is adopted.Besides,a fuzzy controller is proposed to control the variation in quality between the left and right views by comparing the PSNR disparity of two views with a fixed threshold,which is used to quantize the binocular psycho-visual redundancy and adjust the quantization parameter (QP) of the right view correspondingly.The proposed algorithm has been implemented in H.264/AVC video codec,and the experimental results show its effectiveness in rate control while keeping a good quality for the left view,and fewer bits are allocated for the right view so that the overall bit rate is saved by 7.2% at most without the loss of subjective visual quality for stereoscopic video.
文摘自动驾驶智能汽车逐渐普及,其在通过城市路面的沟渠、井盖和减速带等特殊路面时,制动与减速时的稳定性与乘坐舒适性较差,为改善这一状况,对悬架的设计提出了更高的要求。为了提高自动驾驶智能汽车制动与减速时的稳定性,通过融合比例积分微分(Proportional Integral Derivative,PID)与模糊算法,设计了针对这些特殊路面的主动悬架模糊PID控制器,在Matlab/Simulink软件中搭建了半车主动悬架仿真模型,通过惯性测量单元(Inertial Measurement Unit,IMU)实车测量了沟渠路面的路面激励信息,并完成仿真试验。结果表明,当自动驾驶智能汽车在C级路面和沟渠路面行驶时,设计的主动悬架模糊PID控制器较单一算法的控制器更有效地降低了车身垂向加速度、车身俯仰角加速度、车轮动载荷和悬架动行程,改善了悬架性能。
