Based on generalized the variation method, by introducing Hamilton function and Lagrange multiplier, this paper proposed a linear quadratic optimal control strategy for an incomplete controllable system with fixed ter...Based on generalized the variation method, by introducing Hamilton function and Lagrange multiplier, this paper proposed a linear quadratic optimal control strategy for an incomplete controllable system with fixed terminal state and time. Applying the proposed optimal control to the simple two-input dual-stage actuator magnetic head positioning system with three degrees-of-freedom, the simulation results show that the system has no residual vibration at the terminal position and time, which can reduce the total access time during head positioning process. To verify the validation of the optimal control strategy of three degrees-of-freedom spring-mass models in actual magnetic head positioning of hard disk drives, a finite element model of an actual magnetic head positioning system is presented. Substituting the optimal control force from simple three degrees-of-freedom spring-mass models into the finite element model, the simulation results show that the magnetic head also has no residual vibration at the end of track-to-track travel. That is to say, the linear quadratic optimal control technique based on simple two-input dual- stage actuator system with three degrees-of-freedom proposed in this paper is of high reliability for the industrial application of an actual magnetic head positioning system.展开更多
As a major equipment for thermal power plants,the main function of coarse powder separators is to separate particles into size groups according to particle diameter.With the rising coal prices,power plants are using m...As a major equipment for thermal power plants,the main function of coarse powder separators is to separate particles into size groups according to particle diameter.With the rising coal prices,power plants are using more low-density lignite.Consequently,the original equipment does not operate under normal conditions.Therefore,to return the equipment to normal operating conditions,the isokinetic sampling method,computational fluid dynamics(CFD),and discrete phase model(DPM)based on the Euler-Lagrange method are applied in this research to analyze the effect of baffle shapes,baffle numbers,and centrifugal blades on the equipment performance index,like R90.The shape of the baffle plate was optimized and improved.Preferential method was applied to determine the optimal number of baffles to ensure normal working conditions.Results show that curved baffles can suppress the axial negative gradient field below themselves better than rectangular baffles.The curved baffles selected by the optimal seeking method make full use of the negative axial gradient field and provide the particles entering the separation zone at tangential velocity in advance with the addition of centrifugal blades.Thus,pre-separation can be realized.The R90 is 5 at the separator outlet and 95 at the powder return port,indicating that the output capacity of the separator returned to a reasonable operating performance.展开更多
This paper proposes a comprehensive design scheme for the extremum seeking control(ESC)of the unmanned aerial vehicle(UAV)close formation flight.The proposed design scheme combines a Newton-Raphson method with an exte...This paper proposes a comprehensive design scheme for the extremum seeking control(ESC)of the unmanned aerial vehicle(UAV)close formation flight.The proposed design scheme combines a Newton-Raphson method with an extended Kalman filter(EKF)to dynamically estimate the optimal position of the following UAV relative to the leading UAV.To reflect the wake vortex effects reliably,the drag coefficient induced by the wake vortex is considered as a performance function.Then,the performance function is parameterized by the first-order and second-order terms of its Taylor series expansion.Given the excellent performance of nonlinear estimation,the EKF is used to estimate the gradient and the Hessian matrix of the parameterized performance function.The output feedback of the proposed scheme is determined by iterative calculation of the Newton-Raphson method.Compared with the traditional ESC and the classic ESC,the proposed design scheme avoids the slow continuous time integration of the gradient.This allows a faster convergence of relative position extremum.Furthermore,the proposed method can provide a smoother command during the seeking process as the second-order term of the performance function is taken into account.The convergence analysis of the proposed design scheme is accomplished by showing that the output feedback is a supermartingale sequence.To improve estimation performance of the EKF,a improved pigeon-inspired optimization(IPIO)is proposed to automatically tune the noise covariance matrix.Monte Carlo simulations for a three-UAV close formation show that the proposed design scheme is robust to the initial position of the following UAV.展开更多
根据性能寻优控制(Perform ance Seek ing Con trol)优化模式的特点,针对某型涡扇发动机,研究了把发动机性能优化问题描述为线性规划问题。同时针对线性规划方法可能会收敛于局部极小值和非线性方法计算量大的问题,提出了基于LP(L inear...根据性能寻优控制(Perform ance Seek ing Con trol)优化模式的特点,针对某型涡扇发动机,研究了把发动机性能优化问题描述为线性规划问题。同时针对线性规划方法可能会收敛于局部极小值和非线性方法计算量大的问题,提出了基于LP(L inear P rogramm ing)和MAPS(M odel-A ssisted Pattern Search)混合优化方法,并研究了LP和MAPS混合优化方法在航空发动机性能寻优控制中的应用,同时在最大推力控制模式和最小油耗控制模式下进行了仿真。大量仿真结果表明,采用混合优化方法可进一步提高发动机的性能,并且大大减少了计算量。展开更多
基金Project supported by the National Natural Science Foundation of China （No. 10472038）；the Science Foundation of the Ministry of Education of China for Ph.D. Programme （No. 20050730016）；the National Science Foundation of China for 0utstanding Young Researchers （No. 10025208）.
文摘Based on generalized the variation method, by introducing Hamilton function and Lagrange multiplier, this paper proposed a linear quadratic optimal control strategy for an incomplete controllable system with fixed terminal state and time. Applying the proposed optimal control to the simple two-input dual-stage actuator magnetic head positioning system with three degrees-of-freedom, the simulation results show that the system has no residual vibration at the terminal position and time, which can reduce the total access time during head positioning process. To verify the validation of the optimal control strategy of three degrees-of-freedom spring-mass models in actual magnetic head positioning of hard disk drives, a finite element model of an actual magnetic head positioning system is presented. Substituting the optimal control force from simple three degrees-of-freedom spring-mass models into the finite element model, the simulation results show that the magnetic head also has no residual vibration at the end of track-to-track travel. That is to say, the linear quadratic optimal control technique based on simple two-input dual- stage actuator system with three degrees-of-freedom proposed in this paper is of high reliability for the industrial application of an actual magnetic head positioning system.
基金supported by the Innovative Research Team of Henan Polytechnic University (T2020-3).
文摘As a major equipment for thermal power plants,the main function of coarse powder separators is to separate particles into size groups according to particle diameter.With the rising coal prices,power plants are using more low-density lignite.Consequently,the original equipment does not operate under normal conditions.Therefore,to return the equipment to normal operating conditions,the isokinetic sampling method,computational fluid dynamics(CFD),and discrete phase model(DPM)based on the Euler-Lagrange method are applied in this research to analyze the effect of baffle shapes,baffle numbers,and centrifugal blades on the equipment performance index,like R90.The shape of the baffle plate was optimized and improved.Preferential method was applied to determine the optimal number of baffles to ensure normal working conditions.Results show that curved baffles can suppress the axial negative gradient field below themselves better than rectangular baffles.The curved baffles selected by the optimal seeking method make full use of the negative axial gradient field and provide the particles entering the separation zone at tangential velocity in advance with the addition of centrifugal blades.Thus,pre-separation can be realized.The R90 is 5 at the separator outlet and 95 at the powder return port,indicating that the output capacity of the separator returned to a reasonable operating performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.91948204,U20B2071,T2121003 and U1913602)Open Fund/Postdoctoral Fund of the Laboratory of Cognition and Decision Intelligence for Complex Systems,Institute of Automation,Chinese Academy of Sciences(Grant No.CASIA-KFKT-08)。
文摘This paper proposes a comprehensive design scheme for the extremum seeking control(ESC)of the unmanned aerial vehicle(UAV)close formation flight.The proposed design scheme combines a Newton-Raphson method with an extended Kalman filter(EKF)to dynamically estimate the optimal position of the following UAV relative to the leading UAV.To reflect the wake vortex effects reliably,the drag coefficient induced by the wake vortex is considered as a performance function.Then,the performance function is parameterized by the first-order and second-order terms of its Taylor series expansion.Given the excellent performance of nonlinear estimation,the EKF is used to estimate the gradient and the Hessian matrix of the parameterized performance function.The output feedback of the proposed scheme is determined by iterative calculation of the Newton-Raphson method.Compared with the traditional ESC and the classic ESC,the proposed design scheme avoids the slow continuous time integration of the gradient.This allows a faster convergence of relative position extremum.Furthermore,the proposed method can provide a smoother command during the seeking process as the second-order term of the performance function is taken into account.The convergence analysis of the proposed design scheme is accomplished by showing that the output feedback is a supermartingale sequence.To improve estimation performance of the EKF,a improved pigeon-inspired optimization(IPIO)is proposed to automatically tune the noise covariance matrix.Monte Carlo simulations for a three-UAV close formation show that the proposed design scheme is robust to the initial position of the following UAV.
文摘根据性能寻优控制(Perform ance Seek ing Con trol)优化模式的特点,针对某型涡扇发动机,研究了把发动机性能优化问题描述为线性规划问题。同时针对线性规划方法可能会收敛于局部极小值和非线性方法计算量大的问题,提出了基于LP(L inear P rogramm ing)和MAPS(M odel-A ssisted Pattern Search)混合优化方法,并研究了LP和MAPS混合优化方法在航空发动机性能寻优控制中的应用,同时在最大推力控制模式和最小油耗控制模式下进行了仿真。大量仿真结果表明,采用混合优化方法可进一步提高发动机的性能,并且大大减少了计算量。
