Electronics

  2010 SEP 10 - (VerticalNews.com) -- "This paper aims at the blade root moment sensor fault detection and isolation issue for three-bladed wind turbines with horizontal axis. The underlying problem is crucial to the successful application of the individual pitch control system, which plays a key role for reducing the blade loads of large offshore wind turbines," scientists in Delft, Netherlands report.

  "In this paper, a wind turbine model is built based on the closed loop identification technique, where the wind dynamics is included. The fault detection issue is investigated based on the residuals generated by dual Kalman filters. Both additive faults and multiplicative faults are considered in this paper. For the additive fault case, the mean value change detection of the residuals and the generalized likelihood ratio test are utilized respectively. For multiplicative faults, they are handled via the variance change detection of the residuals. The fault isolation issue is proceeded with the help of dual sensor redundancy," wrote X.K. Wei and colleagues, Delft University of Technology ...read more

  2010 SEP 8 - (VerticalNews.com) -- According to recent research from People's Republic of China, "This paper presents a new model for linear time-delay systems with multiple delayed states where each delay contains finite number of successive components with different time-varying properties, referred to as multiple-delay system with successive time-varying delay components (MDSSTDCs)."

  "General stability result and H-infinity performance conditions, under which the MDSSTDCs are asymptotically stable with certain H-infinity disturbance attenuation level, are derived by exploiting a general Lyapunov-Krasovslcii functional and by making use of novel techniques for time-delay systems," wrote G. Guo and colleagues, Dalian Maritime University ...read more

  2010 SEP 8 - (VerticalNews.com) -- According to a study from Beijing, People's Republic of China, "In this paper, a robust adaptive sliding mode controller is presented for delta operator systems with mismatched uncertainties and exogenous disturbances. The parameters of the delta operator system are taken for norm-bounded uncertainties."

  "The exogenous disturbance is also assumed to be bounded. After the statement of a sufficient condition for the existence of linear sliding surface based on linear matrix inequality technique, a robust reaching motion control method for delta operator systems is presented. Afterwards, an adaptive sliding mode controller for delta operator systems is designed. A bridge between the robust adaptive sliding mode control and the delta operator system framework is made," wrote H.J. Yang and colleagues ...read more