Observer-based fault diagnosis in manipulation robots

Modeling and Experiment Design for Identification of Wear in a Robot Joint Under Load and Temperature Uncertainties Based on Friction Data

“…Under the assumption that the effects of load and temperature are independent of those caused by wear, it is possible to extend the model given in (5) to include the effects of wear as…”

“…p(T f |τ l , T, w)N (τ l ; μ τ l , σ 2 τ l ) dτ l (11) which for the Gaussian distribution p(T f |τ l , T, w) given in (10) can be found explicitly since the dependence of τ f (·) on τ l is linear, see (5). The marginal density function is given by [23, p. 93]…”

“…where τ 0 f (φ, τ l , T ) is given by (5) and τ f (φ, w) is described in (7). Tables I and II are used.…”

“…The use of nonlinear observers, as presented in [5]- [10], is important to support control law reconfiguration and fault detection. In [11], an observer is used to estimate friction torques in a rotating machine; the presence of a friction change is detected based on a multiple hypotheses test where each hypothesis is associated to a known friction model.…”

Sensor and actuator fault detection and isolation based on artificial neural networks and fuzzy logic applicated on induction motor

“…The first method used the model of system to generate a signal called residual which becomes large in the case of fault and small in the absence of defect. Sensor and actuator fault are detected and identified using analytical redundancy as presented in the different works [1][2][3][4][5]. A robust residual could distinguish between the fault affecting the system and the false alarm.…”