In this paper, the new hybrid adaptive Volterra filter was proposed to be applied for compensating the nonlinear distortion of memoryless nonlinear systems with saturation characteristics. Through computer simulations...In this paper, the new hybrid adaptive Volterra filter was proposed to be applied for compensating the nonlinear distortion of memoryless nonlinear systems with saturation characteristics. Through computer simulations as well as the analytical analysis, it could be shown that it is possible for both conventional Volterra filter and proposed Volterra filter, to be applied for linearizing the memoryless nonlinear system with nonlinear distortion. Also, the simulation results demonstrated that the proposed Volterra filter may have faster convergence speed and better capability of compensating the nonlinear distortion than the conventional Volterra filter.展开更多
An adaptive controller involving a neural network(NN)compensator is proposed to resist the uncertainties in the Euler-Lagrangian system(ELS).Firstly,a proportional-differential(PD)control law is designed for the nomin...An adaptive controller involving a neural network(NN)compensator is proposed to resist the uncertainties in the Euler-Lagrangian system(ELS).Firstly,a proportional-differential(PD)control law is designed for the nominal model.Meanwhile,the uncertainties including model error and external disturbance are separated from the closed-loop system.Then,an adaptive NN compensator based on the online training mode is proposed to eliminate the adverse effect of the uncertainties.In addition,the stability of the closed-loop system is proved by Lyapunov theory.Finally,the effectiveness of the proposed approach is verified on a two-degree-of-freedom robot manipulator.展开更多
Since the dead zone phenomenon occurs in electro-hydraulic servo system, the output of the system corresponding to a sinusoidal input contains higher harmonic besides the fundamental input, which causes harmonic disto...Since the dead zone phenomenon occurs in electro-hydraulic servo system, the output of the system corresponding to a sinusoidal input contains higher harmonic besides the fundamental input, which causes harmonic distortion of the output signal. The method for harmonic cancellation based on adaptive filter is proposed. The task is accomplished by generating reference signals with frequency that should be eliminated from the output. The reference inputs are weighted by the adaptive filter in such a way that it closely matches the harmonic. The output of the adaptive filter is a harmonic replica and is injected to the fundamental signal such that the output harmonic is cancelled leaving the desired signal alone, and the total harmonic distortion （THD） is greatly reduced. The weights of filter are adjusted on-line according to the control error by using least-mean-square （LMS） algorithm. Simulation results performed with a hydraulic system demonstrate the efficiency and validity of the proposed adaptive feed-forward compensator （AFC） control scheme展开更多
文摘In this paper, the new hybrid adaptive Volterra filter was proposed to be applied for compensating the nonlinear distortion of memoryless nonlinear systems with saturation characteristics. Through computer simulations as well as the analytical analysis, it could be shown that it is possible for both conventional Volterra filter and proposed Volterra filter, to be applied for linearizing the memoryless nonlinear system with nonlinear distortion. Also, the simulation results demonstrated that the proposed Volterra filter may have faster convergence speed and better capability of compensating the nonlinear distortion than the conventional Volterra filter.
基金Shanghai Rising-Star Program,China (No.19QA1400400)Natural Science Foundation of Shanghai,China (No.21ZR1401100)+1 种基金Fundamental Research Funds for the Central Universities,China (No.2232019G-09)Graduate Student Innovation Fund of Donghua University,China (No.CUSF-DH-D-2021052)。
文摘An adaptive controller involving a neural network(NN)compensator is proposed to resist the uncertainties in the Euler-Lagrangian system(ELS).Firstly,a proportional-differential(PD)control law is designed for the nominal model.Meanwhile,the uncertainties including model error and external disturbance are separated from the closed-loop system.Then,an adaptive NN compensator based on the online training mode is proposed to eliminate the adverse effect of the uncertainties.In addition,the stability of the closed-loop system is proved by Lyapunov theory.Finally,the effectiveness of the proposed approach is verified on a two-degree-of-freedom robot manipulator.
文摘Since the dead zone phenomenon occurs in electro-hydraulic servo system, the output of the system corresponding to a sinusoidal input contains higher harmonic besides the fundamental input, which causes harmonic distortion of the output signal. The method for harmonic cancellation based on adaptive filter is proposed. The task is accomplished by generating reference signals with frequency that should be eliminated from the output. The reference inputs are weighted by the adaptive filter in such a way that it closely matches the harmonic. The output of the adaptive filter is a harmonic replica and is injected to the fundamental signal such that the output harmonic is cancelled leaving the desired signal alone, and the total harmonic distortion （THD） is greatly reduced. The weights of filter are adjusted on-line according to the control error by using least-mean-square （LMS） algorithm. Simulation results performed with a hydraulic system demonstrate the efficiency and validity of the proposed adaptive feed-forward compensator （AFC） control scheme
