This paper is concerned with the control synthesis problem via dynamic output feedback for linear continuous-time systems with mixed frequency small gain specifications.A new method for designing dynamic output feedba...This paper is concerned with the control synthesis problem via dynamic output feedback for linear continuous-time systems with mixed frequency small gain specifications.A new method for designing dynamic output feedback controllers is presented such that the resulting closed-loop systems are asymptotically stable and meet the requirements of small gain specifications in both finite frequency ranges and the entire frequency range.The design conditions are given in terms of solutions to a set of linear matrix inequalities(LMIs).Finally,a numerical example is given to illustrate the design procedure and the advantage of the proposed method in comparison with the existing one.展开更多
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
A novel cooling system combining ultra fast cooling rigs with laminar cooling devices was investigated.Based on the different cooling mechanisms,a serial of mathematic models were established to describe the relations...A novel cooling system combining ultra fast cooling rigs with laminar cooling devices was investigated.Based on the different cooling mechanisms,a serial of mathematic models were established to describe the relationship between water flow and spraying pressure and the relationship between water spraying heat flux and layout of nozzles installed on the top and bottom cooling headers.Model parameters were validated by measured data.Heat transfer models including air convection model,heat radiation model and water cooling capacity model were detailedly introduced.In addition,effects on cooling capacity by water temperature and different valve patterns were also presented.Finally,the comparison results from UFC used or not have been provided with respect to temperature evolution and mechanical properties of Q235B steel grade with thickness of 7.8 mm.Since online application of the sophisticated CTC process control system based on these models,run-out table cooling control system has been running stably and reliably to produce resource-saving,low-cost steels with smaller grain size.展开更多
基金Supported by Program for New Century Excellent Talents in University(NCET-04-0283)the Funds for Creative Research Groups of China(60521003)+4 种基金Program for Changjiang Scholars and Innovative Research Team in University(IRT0421)the State Key Program of National Natural Science Foundation of China(60534010)and National Natural Science Foundation of China(60674021)the Funds of Ph.D.Program of Ministry of Education,China(20060145019)the 111 Project(B08015)
文摘This paper is concerned with the control synthesis problem via dynamic output feedback for linear continuous-time systems with mixed frequency small gain specifications.A new method for designing dynamic output feedback controllers is presented such that the resulting closed-loop systems are asymptotically stable and meet the requirements of small gain specifications in both finite frequency ranges and the entire frequency range.The design conditions are given in terms of solutions to a set of linear matrix inequalities(LMIs).Finally,a numerical example is given to illustrate the design procedure and the advantage of the proposed method in comparison with the existing one.
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Project(51034009)supported by the National Natural Science Foundation of China
文摘A novel cooling system combining ultra fast cooling rigs with laminar cooling devices was investigated.Based on the different cooling mechanisms,a serial of mathematic models were established to describe the relationship between water flow and spraying pressure and the relationship between water spraying heat flux and layout of nozzles installed on the top and bottom cooling headers.Model parameters were validated by measured data.Heat transfer models including air convection model,heat radiation model and water cooling capacity model were detailedly introduced.In addition,effects on cooling capacity by water temperature and different valve patterns were also presented.Finally,the comparison results from UFC used or not have been provided with respect to temperature evolution and mechanical properties of Q235B steel grade with thickness of 7.8 mm.Since online application of the sophisticated CTC process control system based on these models,run-out table cooling control system has been running stably and reliably to produce resource-saving,low-cost steels with smaller grain size.
