The general nonlinear system with structural uncertainty is dealt with and necessary conditions for it to be robust passivity are derived. From these necessary conditions, sufficient conditions of zero state detectabi...The general nonlinear system with structural uncertainty is dealt with and necessary conditions for it to be robust passivity are derived. From these necessary conditions, sufficient conditions of zero state detectability are deduced. Based on passive systems theory and the technique of feedback equivalence, sufficient conditions for it to be locally (globally) asymptotically stabilized via smooth state feedback are developed. A smooth state feedback control law can be constructed explicitly to locally (globally) stabilize the equilibrium of the closed-loop system. Simulation example shows the effectiveness of the method.展开更多
The reasons for inducing quadrature error and offset error are analyzed and the expressions of quadrature error and offset error are induced. The open-loop system analysis indicates that, in order to avoid the appeara...The reasons for inducing quadrature error and offset error are analyzed and the expressions of quadrature error and offset error are induced. The open-loop system analysis indicates that, in order to avoid the appearance of harmonic peaks, the frequency difference δf between drive mode and sense mode must be less than 1/（2Qy）. In order to eliminate the effects of the quadrature error and the offset error, as well as the inherent non- linearity in the capacitance-type sensors, a closed-loop feedback control circuit with quadrature correction is designed. The experimental results indicate that the quadrature error and offset error are corrected. By comparing with open-loop detection, the closed-loop feedback control circuit with quadrature correction decreases the non-linearity of the scale factor from 16. 02% to 0. 35 %, widens the maximum rate capability from ± 270 （°）/s to ± 370 （°）/s and increases the stability of zero bias from 155. 2 （°）/h to 60. 6 （°）/h.展开更多
文摘The general nonlinear system with structural uncertainty is dealt with and necessary conditions for it to be robust passivity are derived. From these necessary conditions, sufficient conditions of zero state detectability are deduced. Based on passive systems theory and the technique of feedback equivalence, sufficient conditions for it to be locally (globally) asymptotically stabilized via smooth state feedback are developed. A smooth state feedback control law can be constructed explicitly to locally (globally) stabilize the equilibrium of the closed-loop system. Simulation example shows the effectiveness of the method.
文摘The reasons for inducing quadrature error and offset error are analyzed and the expressions of quadrature error and offset error are induced. The open-loop system analysis indicates that, in order to avoid the appearance of harmonic peaks, the frequency difference δf between drive mode and sense mode must be less than 1/（2Qy）. In order to eliminate the effects of the quadrature error and the offset error, as well as the inherent non- linearity in the capacitance-type sensors, a closed-loop feedback control circuit with quadrature correction is designed. The experimental results indicate that the quadrature error and offset error are corrected. By comparing with open-loop detection, the closed-loop feedback control circuit with quadrature correction decreases the non-linearity of the scale factor from 16. 02% to 0. 35 %, widens the maximum rate capability from ± 270 （°）/s to ± 370 （°）/s and increases the stability of zero bias from 155. 2 （°）/h to 60. 6 （°）/h.
