The variational approach is further applied to the measurement feedback H ∞ control problems. Based on the induced norm description of the system Γ,the variational functionals J c and J p of state feedback H ...The variational approach is further applied to the measurement feedback H ∞ control problems. Based on the induced norm description of the system Γ,the variational functionals J c and J p of state feedback H ∞ control for the future time interval (t,t f ], and of H ∞ filter for the past time interval [0,t), respectively, are combined together to generate the variational functional of the measurement feedback for the whole time interval [0,t f ]. The connection condition at the present time t is that the estimated state vector (t) must be continuously extended to be the initial condition of the future state vector estimation. Another connection condition for the dual vector λ(t) can be naturally derived from the variational principle. The equations thus derived show that the third condition for the optimal parameter γ -2 cr is again a bound of the smallest Rayleigh quotient. Therefore, the precise integration method developed formerly to determine the optimal parameter γ -2 cr of H ∞ control and of H ∞ filter respectively can be further applied to the determination of the optimal parameter.展开更多
Global navigation satellite system(GNSS)positioning depends on the correct integer ambiguity resolu-tion(AR).If the double difference equation for solving the float solution remains il-conditioned,often happening due ...Global navigation satellite system(GNSS)positioning depends on the correct integer ambiguity resolu-tion(AR).If the double difference equation for solving the float solution remains il-conditioned,often happening due to the environment complexity and the equipment mobility,the corrcct AR is difficult to achieve.Concern-ing the il-conditioned problem,methods of modifying the equation cofficient matrix are widely applied,whose effects are heavily dependent on modifying parameters.Besides,the direct inversion of the il-conditioned coef-ficient matrix can lead to a reduction in the accuracy and stability of the float solution.To solve the problem of il-conditioned matrix inversion and further improve the accuracy,the present study for the first time proves the positive definite symmetry of the coefficient matrix in AR model and employs precise integration method to the indirect inverse of cofficient matrix.AR model for the GNSS positioning and the general resolving strate-gies introduction are briefly introduced.An indirect-inversion algorithm via precise integration for il-conditioned coefficient matrix is proposed.According to the simulations and comparisons,the proposed strategy has higher precision and stability on foat solution,and less dependence on modifying parameters.展开更多
Tunisia is located at the northern end of Africa and faces the Mediterranean Sea on the north and the east.In the early 9th century BCE,the Phoenicians built Carthage bordering the Tunisian Gulf,and created the brilli...Tunisia is located at the northern end of Africa and faces the Mediterranean Sea on the north and the east.In the early 9th century BCE,the Phoenicians built Carthage bordering the Tunisian Gulf,and created the brilliant Carthaginian civilization.Now,Tunisia has become a multicultural country integrating a long civilization.China and Tunisia established diplomatic relations on January 10,1964,and despite being separated展开更多
文摘The variational approach is further applied to the measurement feedback H ∞ control problems. Based on the induced norm description of the system Γ,the variational functionals J c and J p of state feedback H ∞ control for the future time interval (t,t f ], and of H ∞ filter for the past time interval [0,t), respectively, are combined together to generate the variational functional of the measurement feedback for the whole time interval [0,t f ]. The connection condition at the present time t is that the estimated state vector (t) must be continuously extended to be the initial condition of the future state vector estimation. Another connection condition for the dual vector λ(t) can be naturally derived from the variational principle. The equations thus derived show that the third condition for the optimal parameter γ -2 cr is again a bound of the smallest Rayleigh quotient. Therefore, the precise integration method developed formerly to determine the optimal parameter γ -2 cr of H ∞ control and of H ∞ filter respectively can be further applied to the determination of the optimal parameter.
文摘Global navigation satellite system(GNSS)positioning depends on the correct integer ambiguity resolu-tion(AR).If the double difference equation for solving the float solution remains il-conditioned,often happening due to the environment complexity and the equipment mobility,the corrcct AR is difficult to achieve.Concern-ing the il-conditioned problem,methods of modifying the equation cofficient matrix are widely applied,whose effects are heavily dependent on modifying parameters.Besides,the direct inversion of the il-conditioned coef-ficient matrix can lead to a reduction in the accuracy and stability of the float solution.To solve the problem of il-conditioned matrix inversion and further improve the accuracy,the present study for the first time proves the positive definite symmetry of the coefficient matrix in AR model and employs precise integration method to the indirect inverse of cofficient matrix.AR model for the GNSS positioning and the general resolving strate-gies introduction are briefly introduced.An indirect-inversion algorithm via precise integration for il-conditioned coefficient matrix is proposed.According to the simulations and comparisons,the proposed strategy has higher precision and stability on foat solution,and less dependence on modifying parameters.
文摘Tunisia is located at the northern end of Africa and faces the Mediterranean Sea on the north and the east.In the early 9th century BCE,the Phoenicians built Carthage bordering the Tunisian Gulf,and created the brilliant Carthaginian civilization.Now,Tunisia has become a multicultural country integrating a long civilization.China and Tunisia established diplomatic relations on January 10,1964,and despite being separated
