Alexey Zhirabok

An optimization approach to the problem of nonlinear diagnostic filter design

The problem of diagnostic filter design is considered for nonlinear dynamic systems. An optimization approach is proposed for this problem solution. Its feature is a combination of unified algebraic - geometric tools involved for nonlinear model transformation with linear optimization techniques. An advantage of the proposed approach is it allows overcoming a principle restriction of existing designing methods and extending the solution to a case of nonlinear system models with uncertainties.

Method of fault isolation in electrical circuits

The problem of fault diagnosis in electrical circuits is studied. The suggested method is based on diagnostic observers. The procedure of observer synthesis for circuits described by linear equations is developed. The existence conditions to design the observer invariant with respect to the fault are considered. The example of electrical circuit and simulation results are given.

Fault diagnosis for nonlinear mechanic systems

The problem of observer-based fault diagnosis in mechatronic systems is studied. To solve this problem, the following approach is suggested: replacing the initial nonlinear system by a certain linear logic-dynamic system, obtaining the bank of linear logic-dynamic observers, and transforming these observers into the nonlinear ones.

Fault Diagnosis in Circuits and Systems by Nonparametric Methods

The problem of fault diagnosis in engineering systems with uncertainties described by nonlinear discrete-time models is studied within the scope of analytical redundancy concept. Solution of the problem assumes the checking redundancy relations existing among system inputs and outputs measured over a finite time window. The nonparametric method is used to construct redundancy relations involving transformation of the initial system model into canonical form with special properties. The obtained results are illustrated by the general electric servoactuator of manipulation robots.

Häiringu kompenseerimine mõõdetava tagasisidega: Sensorite paiknemine

The paper addresses the problem on sensor location regarding the solvability of the disturbance decoupling problem by the dynamic measurement feedback (DDDPM). Both, the discreteand continuous-time nonlinear systems are considered. An exact formula is given to compute a controlled invariant vector function, necessary for the solvability of the DDDPM. Then, two methods are given to find a measured output, which guarantee the solution to the DDDPM. The results are illustrated by several examples.

Fault isolation and estimation in electric servoactuator of manipulation robots

The problem of fault isolation and fault estimation in electric servoactuator of manipulation robots to achieve fault accommodation is considered. A bank of diagnostic observers is used to provide the fault isolation and fault estimation processes. So-called logic-dynamic approach is suggested to solve this problem. The advantage of this approach is that it allows considering the systems with non-smooth nonlinearities by linear methods. The disadvantage consists in possible increase of the observer dimension.