An adaptive current compensation control for a single-sided linear induction motor(SLIM) with nonlinear disturbance observer was developed. First, to maintain t-axis secondary component flux constant with consideratio...An adaptive current compensation control for a single-sided linear induction motor(SLIM) with nonlinear disturbance observer was developed. First, to maintain t-axis secondary component flux constant with consideration of the specially dynamic eddy-effect(DEE) of the SLIM, a instantaneously tracing compensation of m-axis current component was analyzed. Second,adaptive current compensation based on Taylor-discretization algorithm was proposed. Third, an effective kind of nonlinear disturbance observer(NDOB) was employed to estimate and compensate the undesired load vibrations, then the robustness of the control system could be guaranteed. Experimental verification of the feasibility of the proposed method for an SLIM control system was performed, and it showed that the proposed adaptive compensation scheme with NDOB could significantly promote speed dynamical response and minimize speed ripple under the conditions of external load coupled vibrations and unavoidable feedback control variables measured errors, i.e., current and speed.展开更多
The real dynamic thrust measurement system usually tends to be nonlinear due to the complex characteristics of the rig, pipes connection, etc. For a real dynamic measuring system, the nonlinearity must be eliminated b...The real dynamic thrust measurement system usually tends to be nonlinear due to the complex characteristics of the rig, pipes connection, etc. For a real dynamic measuring system, the nonlinearity must be eliminated by some adequate methods. In this paper, a nonlinear model of dynamic thrust measurement system is established by using radial basis function neural network （RBF-NN）, where a novel multi-step force generator is designed to stimulate the nonlinearity of the system, and a practical compensation method for the measurement system using left inverse model is proposed. Left inverse model can be considered as a perfect dynamic compensation of the dynamic thrust measurement system, and in practice, it can be approximated by RBF-NN based on least mean square （LMS） algorithms. Different weights are set for producing the multi-step force, which is the ideal input signal of the nonlinear dynamic thrust measurement system. The validity of the compensation method depends on the engine＇s performance and the tolerance error 0.5%, which is commonly demanded in engineering. Results from simulations and experiments show that the practical compensation using left inverse model based on RBF-NN in dynamic thrust measuring system can yield high tracking accuracy than the conventional methods.展开更多
This article focuses on the problem of how to accurately calculate the joint control torques when the explosion-proof robot performs collision detection without sensors and gives a complete solution.Nonlinear joint fr...This article focuses on the problem of how to accurately calculate the joint control torques when the explosion-proof robot performs collision detection without sensors and gives a complete solution.Nonlinear joint frictions are incorporated into the dynamic model of a robotic manip-ulator to improve calculation accuracy.A genetic algorithm is used to optimise the excitation trajectories to fully stimulate the robot dynamic characteristics.Effective and applicable data filtering and smoothing methods are proposed and the Iteratively Reweighted Least-Squares method based on the error term is applied to identify the robot dynamic parameters.Compared with Ordinary Least-Squares method,the proposed algorithm improves the accuracy of joint control torques estimation.展开更多
This paper investigates the cooperative output regulation problem of linear multi-agent systems with a linear exogenous system(exo-system).The network topology is described by a directed graph which contains a directe...This paper investigates the cooperative output regulation problem of linear multi-agent systems with a linear exogenous system(exo-system).The network topology is described by a directed graph which contains a directed spanning tree with the exo-system as the root.Aiming at improving the transient performance of the multi-agent systems,a dynamic control law is developed by the composite nonlinear feedback(CNF)control technique.In particular,a distributed dynamic compensator independent of the interaction on the compensator states of agents among the network,is adopted.The solvability condition for the cooperative output regulation problem is obtained using the small-gain theory,which will not be destroyed by adding the nonlinear feedback part of the CNF control law.It is also shown that in the case with the exo-system not diverging exponentially,the small-gain condition can be guaranteed using the low-gain design.Finally,simulation results illustrate that the proposed CNF control law improves the transient performance for the cooperative output regulation of linear multi-agent systems.展开更多
Strong chromatic sextupoles used to compensate natural chromaticities in the third generation light source storage ring usually reduce dynamic aperture drastically. Many optimization methods can be used to find soluti...Strong chromatic sextupoles used to compensate natural chromaticities in the third generation light source storage ring usually reduce dynamic aperture drastically. Many optimization methods can be used to find solutions that provide large dynamic apertures. This paper discusses a new optimization approach of sextupole strengths with step-by-step procedure, which is applied in the SSRF storage ring, and a better solution is obtained. Investigating driving terms generated by the sextupoles in every step can analyze their convergences and guide the weight setting among different terms in object function of the single resonance approach based on the perturbation theory.展开更多
基于微分代数控制系统的反馈线性化方法,进一步研究了具有非线性负荷的电力系统中静止无功补偿器(Static var compensator,SVC)和发电机三阶模型的励磁控制,表明具有非线性负荷和SVC装置的NDAS(3)仍可以通过状态反馈精确线性化,从而得...基于微分代数控制系统的反馈线性化方法,进一步研究了具有非线性负荷的电力系统中静止无功补偿器(Static var compensator,SVC)和发电机三阶模型的励磁控制,表明具有非线性负荷和SVC装置的NDAS(3)仍可以通过状态反馈精确线性化,从而得到具有代数方程的Brunovsky标准型。提出了具有非线性负荷的电力系统SVC与发电机励磁控制的完全精确线性化设计。该控制方法可以同时满足发电机功角稳定和SVC节点处电压。仿真结果表明该方法具有很好的效果和优越性。展开更多
基金Project(114601034)supported by the Scholarship Award for Excellent Doctoral Students Granted by the Ministry of Education of ChinaProject(61273158)supported by the National Natural Science Foundation of China
文摘An adaptive current compensation control for a single-sided linear induction motor(SLIM) with nonlinear disturbance observer was developed. First, to maintain t-axis secondary component flux constant with consideration of the specially dynamic eddy-effect(DEE) of the SLIM, a instantaneously tracing compensation of m-axis current component was analyzed. Second,adaptive current compensation based on Taylor-discretization algorithm was proposed. Third, an effective kind of nonlinear disturbance observer(NDOB) was employed to estimate and compensate the undesired load vibrations, then the robustness of the control system could be guaranteed. Experimental verification of the feasibility of the proposed method for an SLIM control system was performed, and it showed that the proposed adaptive compensation scheme with NDOB could significantly promote speed dynamical response and minimize speed ripple under the conditions of external load coupled vibrations and unavoidable feedback control variables measured errors, i.e., current and speed.
文摘The real dynamic thrust measurement system usually tends to be nonlinear due to the complex characteristics of the rig, pipes connection, etc. For a real dynamic measuring system, the nonlinearity must be eliminated by some adequate methods. In this paper, a nonlinear model of dynamic thrust measurement system is established by using radial basis function neural network （RBF-NN）, where a novel multi-step force generator is designed to stimulate the nonlinearity of the system, and a practical compensation method for the measurement system using left inverse model is proposed. Left inverse model can be considered as a perfect dynamic compensation of the dynamic thrust measurement system, and in practice, it can be approximated by RBF-NN based on least mean square （LMS） algorithms. Different weights are set for producing the multi-step force, which is the ideal input signal of the nonlinear dynamic thrust measurement system. The validity of the compensation method depends on the engine＇s performance and the tolerance error 0.5%, which is commonly demanded in engineering. Results from simulations and experiments show that the practical compensation using left inverse model based on RBF-NN in dynamic thrust measuring system can yield high tracking accuracy than the conventional methods.
基金supported by the National Key Research and Development Program:[Grant Number 2018YFB1305700].
文摘This article focuses on the problem of how to accurately calculate the joint control torques when the explosion-proof robot performs collision detection without sensors and gives a complete solution.Nonlinear joint frictions are incorporated into the dynamic model of a robotic manip-ulator to improve calculation accuracy.A genetic algorithm is used to optimise the excitation trajectories to fully stimulate the robot dynamic characteristics.Effective and applicable data filtering and smoothing methods are proposed and the Iteratively Reweighted Least-Squares method based on the error term is applied to identify the robot dynamic parameters.Compared with Ordinary Least-Squares method,the proposed algorithm improves the accuracy of joint control torques estimation.
基金This work was supported in part by the National Natural Science Foundation of China under Grants 62273285 and 62173283in part by the Natural Science Foundation of Fujian Province of China under Grants 2021J01051.
文摘This paper investigates the cooperative output regulation problem of linear multi-agent systems with a linear exogenous system(exo-system).The network topology is described by a directed graph which contains a directed spanning tree with the exo-system as the root.Aiming at improving the transient performance of the multi-agent systems,a dynamic control law is developed by the composite nonlinear feedback(CNF)control technique.In particular,a distributed dynamic compensator independent of the interaction on the compensator states of agents among the network,is adopted.The solvability condition for the cooperative output regulation problem is obtained using the small-gain theory,which will not be destroyed by adding the nonlinear feedback part of the CNF control law.It is also shown that in the case with the exo-system not diverging exponentially,the small-gain condition can be guaranteed using the low-gain design.Finally,simulation results illustrate that the proposed CNF control law improves the transient performance for the cooperative output regulation of linear multi-agent systems.
文摘Strong chromatic sextupoles used to compensate natural chromaticities in the third generation light source storage ring usually reduce dynamic aperture drastically. Many optimization methods can be used to find solutions that provide large dynamic apertures. This paper discusses a new optimization approach of sextupole strengths with step-by-step procedure, which is applied in the SSRF storage ring, and a better solution is obtained. Investigating driving terms generated by the sextupoles in every step can analyze their convergences and guide the weight setting among different terms in object function of the single resonance approach based on the perturbation theory.
文摘基于微分代数控制系统的反馈线性化方法,进一步研究了具有非线性负荷的电力系统中静止无功补偿器(Static var compensator,SVC)和发电机三阶模型的励磁控制,表明具有非线性负荷和SVC装置的NDAS(3)仍可以通过状态反馈精确线性化,从而得到具有代数方程的Brunovsky标准型。提出了具有非线性负荷的电力系统SVC与发电机励磁控制的完全精确线性化设计。该控制方法可以同时满足发电机功角稳定和SVC节点处电压。仿真结果表明该方法具有很好的效果和优越性。
