Aiming at solving the problems of response lag and lack of precision and stability in constant grinding force control of industrial robot belts,a constant force control strategy combining fuzzy control and proportion ...Aiming at solving the problems of response lag and lack of precision and stability in constant grinding force control of industrial robot belts,a constant force control strategy combining fuzzy control and proportion integration differentiation(PID)was proposed by analyzing the signal transmission process and the dynamic characteristics of the grinding mechanism.The simulation results showed that compared with the classical PID control strategy,the system adjustment time was shortened by 98.7%,the overshoot was reduced by 5.1%,and the control error was 0.2%-0.5%when the system was stabilized.The optimized fuzzy control system had fast adjustment speeds,precise force control and stability.The experimental analysis of the surface morphology of the machined blade was carried out by the industrial robot abrasive grinding mechanism,and the correctness of the theoretical analysis and the effectiveness of the control strategy were verified.展开更多
The technology of attitude control for quadrotor unmanned aerial vehicles(UAVs) is one of the most important UAVs' research areas.In order to achieve a satisfactory operation in quadrotor UAVs having proportional ...The technology of attitude control for quadrotor unmanned aerial vehicles(UAVs) is one of the most important UAVs' research areas.In order to achieve a satisfactory operation in quadrotor UAVs having proportional integration differential(PID) controllers,it is necessary to appropriately adjust the controller coefficients which are dependent on dynamic parameters of the quadrotor UAV and any changes in parameters and conditions could affect desired performance of the controller.In this paper,combining with PID control and fuzzy logic control,a kind of fuzzy self-adaptive PID control algorithm for attitude stabilization of the quadrotor UAV was put forward.Firstly,the nonlinear model of six degrees of freedom(6-DOF) for quadrotor UAV is established.Secondly,for obtaining the attitude of quadrotor,attitude data fusion using complementary filtering is applied to improving the measurement accuracy and dynamic performance.Finally,the attitude stabilization control simulation model of the quadrotor UAV is build,and the self-adaptive fuzzy parameter tuning rules for PID attitude controller are given,so as to realize the online self-tuning of the controller parameters.Simulation results show that comparing with the conventional PID controller,this attitude control algorithm of fuzzy self-adaptive PID has a better dynamic response performance.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
In order to improve the efficiency and precision of maximum power point tracking(MPPT)control,a new method is proposed.Based on original MPPT technology of photovoltaic cells,the fuzzy adaptive proportion-integral-dif...In order to improve the efficiency and precision of maximum power point tracking(MPPT)control,a new method is proposed.Based on original MPPT technology of photovoltaic cells,the fuzzy adaptive proportion-integral-differential(PID)control has less fluctuation and higher stability.The simulation circuit using Simulink is established,and output power curves under constant temperature or constant sunlight are obtained.The superiority of the fuzzy PID control method has been proved by means of the simulation results,and it makes the solar system approach maximum power point quickly and smoothly.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
基金Civil Project of China Aerospace Science and Technology CorporationUniversity-Industry Collaborative Education Program of Ministry of Education of China(No.220906517214433)。
文摘Aiming at solving the problems of response lag and lack of precision and stability in constant grinding force control of industrial robot belts,a constant force control strategy combining fuzzy control and proportion integration differentiation(PID)was proposed by analyzing the signal transmission process and the dynamic characteristics of the grinding mechanism.The simulation results showed that compared with the classical PID control strategy,the system adjustment time was shortened by 98.7%,the overshoot was reduced by 5.1%,and the control error was 0.2%-0.5%when the system was stabilized.The optimized fuzzy control system had fast adjustment speeds,precise force control and stability.The experimental analysis of the surface morphology of the machined blade was carried out by the industrial robot abrasive grinding mechanism,and the correctness of the theoretical analysis and the effectiveness of the control strategy were verified.
基金National Natural Science Foundation of China(No.61374114)Natural Science Foundation of Liaoning Province,China(No.2015020022)the Fundamental Research Funds for the Central Universities,China(No.3132015039)
文摘The technology of attitude control for quadrotor unmanned aerial vehicles(UAVs) is one of the most important UAVs' research areas.In order to achieve a satisfactory operation in quadrotor UAVs having proportional integration differential(PID) controllers,it is necessary to appropriately adjust the controller coefficients which are dependent on dynamic parameters of the quadrotor UAV and any changes in parameters and conditions could affect desired performance of the controller.In this paper,combining with PID control and fuzzy logic control,a kind of fuzzy self-adaptive PID control algorithm for attitude stabilization of the quadrotor UAV was put forward.Firstly,the nonlinear model of six degrees of freedom(6-DOF) for quadrotor UAV is established.Secondly,for obtaining the attitude of quadrotor,attitude data fusion using complementary filtering is applied to improving the measurement accuracy and dynamic performance.Finally,the attitude stabilization control simulation model of the quadrotor UAV is build,and the self-adaptive fuzzy parameter tuning rules for PID attitude controller are given,so as to realize the online self-tuning of the controller parameters.Simulation results show that comparing with the conventional PID controller,this attitude control algorithm of fuzzy self-adaptive PID has a better dynamic response performance.
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In order to improve the efficiency and precision of maximum power point tracking(MPPT)control,a new method is proposed.Based on original MPPT technology of photovoltaic cells,the fuzzy adaptive proportion-integral-differential(PID)control has less fluctuation and higher stability.The simulation circuit using Simulink is established,and output power curves under constant temperature or constant sunlight are obtained.The superiority of the fuzzy PID control method has been proved by means of the simulation results,and it makes the solar system approach maximum power point quickly and smoothly.
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。
