In recent years, Apolygus htcorum has become the main pest of winter jujube. It sucks juice of young parts of winter jujube and causes falling of buds and flowers, leaf perforations, deformities and fall- off of fruit...In recent years, Apolygus htcorum has become the main pest of winter jujube. It sucks juice of young parts of winter jujube and causes falling of buds and flowers, leaf perforations, deformities and fall- off of fruits, leading to serious economic loss. Considering the occurrence characteristics and control problems, the distribution, occurrence regularity, damage characteristics and outbreak reasons of A. lucorum are overviewed and analyzed in this paper, and the pollution-free control measures are also put forward.展开更多
The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa(aphids and thrips)were compared in three sites across China’s alfalfa belt.In addition,the persistence of ...The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa(aphids and thrips)were compared in three sites across China’s alfalfa belt.In addition,the persistence of the residues of chemical insecticides in alfalfa and their influence on the quality of alfalfa hay were examined.Efficacy varied among the different biological and chemical insecticides.The chemical insecticides were significantly more effective than biopesticides in a short time-frame.The efficacy period of biopesticides was significantly longer than that of chemical insecticides,and the corrected mortality rate of aphids in all regions was above 50%at 14 days after application.The analysis of pesticide residues showed that the residual doses of all the pesticides were within the allowed ranges after the safe period.The acid detergent fiber and neutral detergent fiber contents in alfalfa hay were higher and the protein content was lower in chemical insecticide treatments than in biopesticide treatments in Hebei.The relative feeding value of alfalfa hay treated with Metarhizium anisopliae IPP330189 was the highest among the treatments.Compared with chemical insecticides,the yield of alfalfa hay was higher in the biopesticides treatments.Biopesticides show a stronger control effect on insect populations and also a better improvement in the quality of alfalfa hay than chemical insecticides.This study provides a basis for exploring and developing a comprehensive control regime for alfalfa insect pests in the different alfalfa-growing regions in China,and for reducing chemical insecticide usage and improving forage quality.展开更多
In order to improve the slurry pH control accuracy of the absorption tower in the wet flue gas desulfurization process,a model free adaptive predictive control algorithm for the desulfurization slurry pH which is base...In order to improve the slurry pH control accuracy of the absorption tower in the wet flue gas desulfurization process,a model free adaptive predictive control algorithm for the desulfurization slurry pH which is based on a cyber physical systems framework is proposed.First,aiming to address system characteristics of non-linearity and pure hysteresis in slurry pH change process,a model free adaptive predictive control algorithm based on compact form dynamic linearization is proposed by combining model free adaptive control algorithm with model predictive control algorithm.Then,by integrating information resources with the physical resources in the absorption tower slurry pH control process,an absorption tower slurry pH optimization control system based on cyber physical systems is constructed.It is turned out that the model free adaptive predictive control algorithm under the framework of the cyber physical systems can effectively realize the high-precision tracking control of the slurry pH of the absorption tower,and it has strong robustness.展开更多
This paper is concerned with the synchronization of delayed neural networks via sampled-data control. A new technique, namely, the free-matrix-based time-dependent discontinuous Lyapunov functional approach, is adopte...This paper is concerned with the synchronization of delayed neural networks via sampled-data control. A new technique, namely, the free-matrix-based time-dependent discontinuous Lyapunov functional approach, is adopted in constructing the Lyapunov functional, which takes advantage of the sampling characteristic of sawtooth input delay. Based on this discontinuous Lyapunov functional, some less conservative synchronization criteria are established to ensure that the slave system is synchronous with the master system. The desired sampled-data controller can be obtained through the use of the linear matrix inequality(LMI) technique. Finally, two numerical examples are provided to demonstrate the effectiveness and the improvements of the proposed methods.展开更多
In the twin-roll strip casting process, hot cast strips can be broken or tom if the casting speed does not match the rolling speed. Usually, a certain length of hot steel strip is hung freely between the caster and ro...In the twin-roll strip casting process, hot cast strips can be broken or tom if the casting speed does not match the rolling speed. Usually, a certain length of hot steel strip is hung freely between the caster and rolling mill to deal with the effect of this speed difference. In this paper,the freely hanging hot steel strip is referred to as the free loop of hot steel strip. Accurately measuring and controlling the height of this free loop is the key factor in maintaining a stable casting operation. Several methods for measuring the loop height of a steel strip are discussed and a method for accurately measuring and controlling the free loop height of hot steel strip is presented. Based on the results of the casting loop quantity change curve, this control method is confirmed to be effective and able to meet the requirements of continuous casting strip production.展开更多
The control of a free-floating space manipulator system isdiscussed. With the augmentation approach, the nonlinearparameterization problem of the dynamic equations of the spacemanipulator system is overcome. Based on ...The control of a free-floating space manipulator system isdiscussed. With the augmentation approach, the nonlinearparameterization problem of the dynamic equations of the spacemanipulator system is overcome. Based on the results, the robustcontrol scheme for free-floating space manipulator with uncer- tainpayload parameters to track the desired trajectory in jointspace isproposed, and the global convergence of the tracking is verified byusing the Lyapunov method.展开更多
To eliminate the node traction coupling during wind turbine blade full-scale static testing,a model free adaptive control algorithm is presented based on fuzzy control performance function compensation. Based on the u...To eliminate the node traction coupling during wind turbine blade full-scale static testing,a model free adaptive control algorithm is presented based on fuzzy control performance function compensation. Based on the universal model theory,the fuzzy model free adaptive control( FMFAC) algorithm is designed by configuring the spot static testing experiences as compensation function F( ·). Then the algorithm implementation process is provided and its quick convergence is proved. Using software to establish static load coupling model of multi-nodes,simulate and verify the validity of FMFAC algorithm,which is applied to wind turbines blade full-scale static testing. The results show that the adaptive decoupling ability of FMFAC is better. The traction of four load points can stay steady and change coordinately. Process error is not over ± 6 k N. The error rate is lower than 1% in special phase.This algorithm effectively eliminates the traction coupling of the static testing process,and makes wind turbine blade testing steadily.展开更多
To study the rolling control characteristics of a canard-controlled missile, a series of wind tunnel experiment is conducted. The experimental method, the structure features of wind tunnel model and the experimental r...To study the rolling control characteristics of a canard-controlled missile, a series of wind tunnel experiment is conducted. The experimental method, the structure features of wind tunnel model and the experimental results are introduced in this paper. The experimental data show that the canard is an inefficient rolling control device for canard-controlled missile with fixed tail fins; but for the free-spinning tail fin configuration, the canard can conduct rolling control of the missile, and even have higher controlling efficiency under larger canard deflection angle.展开更多
A model-free adaptive control method is proposed for the spacecrafts whose dynamical parameters change over time and cannot be acquired accurately. The algorithm is based on full form dynamic linearization.A dimension...A model-free adaptive control method is proposed for the spacecrafts whose dynamical parameters change over time and cannot be acquired accurately. The algorithm is based on full form dynamic linearization.A dimension reduction matrix is introduced to construct an augmented system with the same dimension input and output. The design of the controller depends on the system input and output data rather than the knowledge of the controlled plant. The numerical simulation results show that the improved controller can deal with different models with the same set of controller parameters,and the controller performance is better than that of PD controller for the time-varying system with disturbance.展开更多
A new method of modeling discrete networked control systems with both the time-varying delay and packet loss was presented in this paper.The network-induced delay is time-varying and it can be smaller or larger than o...A new method of modeling discrete networked control systems with both the time-varying delay and packet loss was presented in this paper.The network-induced delay is time-varying and it can be smaller or larger than one sampling period.The feedback controller was designed by free-weighting matrices method and Lyapunov-Krasovskii functional to make the networked control system asymptotically stable.And sufficient conditions were derived.A numerical example is given to illustrate the effectiveness of the proposed approach.展开更多
Based on analyzing the overlap appearance of random winding, basic principles of ribbon-free random winding and parametric selections for anti-overlap are discussed. The ribbon-free random winding control system and i...Based on analyzing the overlap appearance of random winding, basic principles of ribbon-free random winding and parametric selections for anti-overlap are discussed. The ribbon-free random winding control system and its related hardware construction as well as its software design are introduced by applying PCC technology to high speed spinning machine of synthetic filament.展开更多
The nonholonomic motion planning of a free-falling cat is investigated. Nonholonomicity arises in a free-falling cat subject to nonintegrable angle velocity constraints or nonintegrable conservation laws. When the tot...The nonholonomic motion planning of a free-falling cat is investigated. Nonholonomicity arises in a free-falling cat subject to nonintegrable angle velocity constraints or nonintegrable conservation laws. When the total angular momentum is zero, the motion equation of a free-falling cat is established based on the model of two symmetric rigid bodies and conservation of angular momentum. The control of system can be converted to the problem of nonholonomic motion planning for a free-falling cat. Based on Ritz approximation theory, the Gauss-Newton method for motion planning by a falling cat is proposed. The effectiveness of the numerical algorithm is demonstrated through simulation on model of a free-falling cat.展开更多
基金Supported by Special Fund for Agro-scientific Research in the Public Interest ( 201103012)
文摘In recent years, Apolygus htcorum has become the main pest of winter jujube. It sucks juice of young parts of winter jujube and causes falling of buds and flowers, leaf perforations, deformities and fall- off of fruits, leading to serious economic loss. Considering the occurrence characteristics and control problems, the distribution, occurrence regularity, damage characteristics and outbreak reasons of A. lucorum are overviewed and analyzed in this paper, and the pollution-free control measures are also put forward.
基金supported by China Agriculture Research System of MOF and MARA(CARS-34).
文摘The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa(aphids and thrips)were compared in three sites across China’s alfalfa belt.In addition,the persistence of the residues of chemical insecticides in alfalfa and their influence on the quality of alfalfa hay were examined.Efficacy varied among the different biological and chemical insecticides.The chemical insecticides were significantly more effective than biopesticides in a short time-frame.The efficacy period of biopesticides was significantly longer than that of chemical insecticides,and the corrected mortality rate of aphids in all regions was above 50%at 14 days after application.The analysis of pesticide residues showed that the residual doses of all the pesticides were within the allowed ranges after the safe period.The acid detergent fiber and neutral detergent fiber contents in alfalfa hay were higher and the protein content was lower in chemical insecticide treatments than in biopesticide treatments in Hebei.The relative feeding value of alfalfa hay treated with Metarhizium anisopliae IPP330189 was the highest among the treatments.Compared with chemical insecticides,the yield of alfalfa hay was higher in the biopesticides treatments.Biopesticides show a stronger control effect on insect populations and also a better improvement in the quality of alfalfa hay than chemical insecticides.This study provides a basis for exploring and developing a comprehensive control regime for alfalfa insect pests in the different alfalfa-growing regions in China,and for reducing chemical insecticide usage and improving forage quality.
基金Supported by National Natural Science Foundation of China(61873006,61673053)National Key Research and Development Project(2018YFC1602704,2018YFB1702704)。
文摘In order to improve the slurry pH control accuracy of the absorption tower in the wet flue gas desulfurization process,a model free adaptive predictive control algorithm for the desulfurization slurry pH which is based on a cyber physical systems framework is proposed.First,aiming to address system characteristics of non-linearity and pure hysteresis in slurry pH change process,a model free adaptive predictive control algorithm based on compact form dynamic linearization is proposed by combining model free adaptive control algorithm with model predictive control algorithm.Then,by integrating information resources with the physical resources in the absorption tower slurry pH control process,an absorption tower slurry pH optimization control system based on cyber physical systems is constructed.It is turned out that the model free adaptive predictive control algorithm under the framework of the cyber physical systems can effectively realize the high-precision tracking control of the slurry pH of the absorption tower,and it has strong robustness.
基金Project supported by the National Natural Science Foundation of China(Grant No.61304064)the Scientific Research Fund of Hunan Provincial Education Department,China(Grant Nos.15B067 and 16C0475)a Discovering Grant from Australian Research Council
文摘This paper is concerned with the synchronization of delayed neural networks via sampled-data control. A new technique, namely, the free-matrix-based time-dependent discontinuous Lyapunov functional approach, is adopted in constructing the Lyapunov functional, which takes advantage of the sampling characteristic of sawtooth input delay. Based on this discontinuous Lyapunov functional, some less conservative synchronization criteria are established to ensure that the slave system is synchronous with the master system. The desired sampled-data controller can be obtained through the use of the linear matrix inequality(LMI) technique. Finally, two numerical examples are provided to demonstrate the effectiveness and the improvements of the proposed methods.
文摘In the twin-roll strip casting process, hot cast strips can be broken or tom if the casting speed does not match the rolling speed. Usually, a certain length of hot steel strip is hung freely between the caster and rolling mill to deal with the effect of this speed difference. In this paper,the freely hanging hot steel strip is referred to as the free loop of hot steel strip. Accurately measuring and controlling the height of this free loop is the key factor in maintaining a stable casting operation. Several methods for measuring the loop height of a steel strip are discussed and a method for accurately measuring and controlling the free loop height of hot steel strip is presented. Based on the results of the casting loop quantity change curve, this control method is confirmed to be effective and able to meet the requirements of continuous casting strip production.
基金the National Natural Science Foundation of China(No.19872032) Aeronautical Science FoandationScience Foundation of Fuzhou University
文摘The control of a free-floating space manipulator system isdiscussed. With the augmentation approach, the nonlinearparameterization problem of the dynamic equations of the spacemanipulator system is overcome. Based on the results, the robustcontrol scheme for free-floating space manipulator with uncer- tainpayload parameters to track the desired trajectory in jointspace isproposed, and the global convergence of the tracking is verified byusing the Lyapunov method.
基金National Natural Science Foundation of China(No.51567018)
文摘To eliminate the node traction coupling during wind turbine blade full-scale static testing,a model free adaptive control algorithm is presented based on fuzzy control performance function compensation. Based on the universal model theory,the fuzzy model free adaptive control( FMFAC) algorithm is designed by configuring the spot static testing experiences as compensation function F( ·). Then the algorithm implementation process is provided and its quick convergence is proved. Using software to establish static load coupling model of multi-nodes,simulate and verify the validity of FMFAC algorithm,which is applied to wind turbines blade full-scale static testing. The results show that the adaptive decoupling ability of FMFAC is better. The traction of four load points can stay steady and change coordinately. Process error is not over ± 6 k N. The error rate is lower than 1% in special phase.This algorithm effectively eliminates the traction coupling of the static testing process,and makes wind turbine blade testing steadily.
文摘To study the rolling control characteristics of a canard-controlled missile, a series of wind tunnel experiment is conducted. The experimental method, the structure features of wind tunnel model and the experimental results are introduced in this paper. The experimental data show that the canard is an inefficient rolling control device for canard-controlled missile with fixed tail fins; but for the free-spinning tail fin configuration, the canard can conduct rolling control of the missile, and even have higher controlling efficiency under larger canard deflection angle.
基金Sponsored by the National Natural Science Foundation of China(Grant No.11102007)the Fundamental Research Fund for the Central Universities(Grant No.YWF-14-YHXY-012)
文摘A model-free adaptive control method is proposed for the spacecrafts whose dynamical parameters change over time and cannot be acquired accurately. The algorithm is based on full form dynamic linearization.A dimension reduction matrix is introduced to construct an augmented system with the same dimension input and output. The design of the controller depends on the system input and output data rather than the knowledge of the controlled plant. The numerical simulation results show that the improved controller can deal with different models with the same set of controller parameters,and the controller performance is better than that of PD controller for the time-varying system with disturbance.
基金National Natural Science Foundation of China(No.70701012)Youth Science and Technology Special Fund of Heilongjiang Province of China(No.QC07C15)
文摘A new method of modeling discrete networked control systems with both the time-varying delay and packet loss was presented in this paper.The network-induced delay is time-varying and it can be smaller or larger than one sampling period.The feedback controller was designed by free-weighting matrices method and Lyapunov-Krasovskii functional to make the networked control system asymptotically stable.And sufficient conditions were derived.A numerical example is given to illustrate the effectiveness of the proposed approach.
基金Supported by the National Natural Science Foundation of China under Grant Nos.60774016,60875039,60904022the Science Foundation of Education Office of Shandong Province of China under Grant No.J08LJ01Internal Visiting Scholar Object for Excellence Youth Teacher of the College of Shandong Province of China
基金The project supported by the Key Program of National Natural Science Foundation of China under Grant No. 70431002 and National Natural Science Foundation of China under Grant Nos. 70371068 and 10247005 The authors thank Drs. Atay and Chun-Guang Li for their useful advices and discussions.
文摘在纸,我们学习效果没有规模(SF ) 在联合地图格子(电流型逻辑) 的动态同步和控制上的拓扑学。我们的策略是使用三个反馈控制方法,包括经常的反馈和推迟时间的反馈的二种类型,到到达需要的同步状态的网络节点的小部分。二控制分叉图诗句反馈力量分别地被获得。当£线性地被增加,为第一推迟时间的反馈控制的批评反馈力量γ _ c 的值线性地被增加,这被发现。有 SF 的电流型逻辑失去同步,如果γ 】
γ _ c.Numerical 例子被举表明所有结果, intermittency 发生。
文摘Based on analyzing the overlap appearance of random winding, basic principles of ribbon-free random winding and parametric selections for anti-overlap are discussed. The ribbon-free random winding control system and its related hardware construction as well as its software design are introduced by applying PCC technology to high speed spinning machine of synthetic filament.
基金Project supported by the National Natural Science Foundation of China (No.10372014)the Natural Science Foundation of Beijing (No.1072008)
文摘The nonholonomic motion planning of a free-falling cat is investigated. Nonholonomicity arises in a free-falling cat subject to nonintegrable angle velocity constraints or nonintegrable conservation laws. When the total angular momentum is zero, the motion equation of a free-falling cat is established based on the model of two symmetric rigid bodies and conservation of angular momentum. The control of system can be converted to the problem of nonholonomic motion planning for a free-falling cat. Based on Ritz approximation theory, the Gauss-Newton method for motion planning by a falling cat is proposed. The effectiveness of the numerical algorithm is demonstrated through simulation on model of a free-falling cat.