In the wireless guidance system, the signals that receiver received has obvious Doppler shift for the high dynamic characteristic of the carrier. A new solution of carrier frequency tracking loop with frequency modify...In the wireless guidance system, the signals that receiver received has obvious Doppler shift for the high dynamic characteristic of the carrier. A new solution of carrier frequency tracking loop with frequency modifying system is put forward. The characteristic of cross product auto frequency control and the second order loop filter in this loop are analyzed. The simulation shows that this loop can accomplish frequency tracking well in high dynamic circumstance.展开更多
High dynamic tracking performance is a key technical index of hydraulic flight motion simulator(HFMS).However,the strong nonlinearities,various model uncertainties and measurement noise in hydraulic actuation systems ...High dynamic tracking performance is a key technical index of hydraulic flight motion simulator(HFMS).However,the strong nonlinearities,various model uncertainties and measurement noise in hydraulic actuation systems limit the high dynamic performance improvement.In this paper,the outer axis frame of a HFMS is taken as a case study and its nonlinear dynamic model with consideration of strong nonlinearities,matched and mismatched uncertainties is established.A novel cascaded extended state observer(ESO)is proposed to estimate the unavailable system states to avoid the adverse effect of measurement noise on control performance.Meanwhile,the designed cascaded ESO also produces estimates of matched and mismatched uncertainties.Then,an output feedback robust controller(OFRC)is proposed by integrating the cascaded ESO with a robust integral of the sign of the error(RISE)feedback based on the backstepping framework.The proposed controller achieves compensation of both matched and mismatched model uncertainties in an output feedback form.Theoretical analysis indicates that the proposed OFRC ensures the boundedness of all closed-loop system signals in the presence of matched and mismatched timevarying model uncertainties.Excellent asymptotic tracking performance can also be obtained when the model uncertainties are time-invariant.Comparative experimental results show that the proposed OFRC achieves significant performance improvement compared with the extensively employed PI control with velocity feedforward(VFPI).展开更多
文摘In the wireless guidance system, the signals that receiver received has obvious Doppler shift for the high dynamic characteristic of the carrier. A new solution of carrier frequency tracking loop with frequency modifying system is put forward. The characteristic of cross product auto frequency control and the second order loop filter in this loop are analyzed. The simulation shows that this loop can accomplish frequency tracking well in high dynamic circumstance.
基金supported in part by the National Natural Science Foundation of China under Grant 51905271,Grant 52075262in part by the Natural Science Foundation of Jiangsu Province under Grant BK20190459+1 种基金in part by the Fundamental Research Funds for the Central Universities under Grant 30920041101in part by the Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems under Grant GZKF-201910。
文摘High dynamic tracking performance is a key technical index of hydraulic flight motion simulator(HFMS).However,the strong nonlinearities,various model uncertainties and measurement noise in hydraulic actuation systems limit the high dynamic performance improvement.In this paper,the outer axis frame of a HFMS is taken as a case study and its nonlinear dynamic model with consideration of strong nonlinearities,matched and mismatched uncertainties is established.A novel cascaded extended state observer(ESO)is proposed to estimate the unavailable system states to avoid the adverse effect of measurement noise on control performance.Meanwhile,the designed cascaded ESO also produces estimates of matched and mismatched uncertainties.Then,an output feedback robust controller(OFRC)is proposed by integrating the cascaded ESO with a robust integral of the sign of the error(RISE)feedback based on the backstepping framework.The proposed controller achieves compensation of both matched and mismatched model uncertainties in an output feedback form.Theoretical analysis indicates that the proposed OFRC ensures the boundedness of all closed-loop system signals in the presence of matched and mismatched timevarying model uncertainties.Excellent asymptotic tracking performance can also be obtained when the model uncertainties are time-invariant.Comparative experimental results show that the proposed OFRC achieves significant performance improvement compared with the extensively employed PI control with velocity feedforward(VFPI).
