Sliding mode functional observers for descriptor systems

This paper addresses the problem of estimating a linear function of the states of a descriptor system using sliding mode functional observer approach. Sliding mode functional observers proposed in this paper are of low-order and do not include the derivatives of the outputs. New conditions for the existence of sliding mode functional observers are derived. A design procedure for the determination of the observer parameters can also be easily derived based on the derived existence conditions

Unknown input sliding mode functional observers with application to sensorless control of permanent magnet synchronous machines

This paper illustrates a method of designing a sliding mode linear functional observer for a system with unknown inputs. The existence conditions for the observer are presented. A structure and design algorithm for the sliding mode observer is proposed. The proposed algorithm is then applied for sensorless control of Permanent Magnet Synchronous Machines

A fault detection technique for dynamical systems

This paper shows how a functional observer can be utilized to detect faults in LTI MIMO systems. The fault detection technique is designed so that the functional observer based fault indicator asymptotically converges to a fault indicator that can be derived based on the nominal system. The asymptotic value of the proposed fault indicator is not dependent on the functional observer parameters; moreover, by choosing appropriate functional observer parameters the convergence rate of the fault indicator can be altered. Observability of the system is not a requirement for the design of the fault detection scheme. © 2013 IEEE