Actuator fault diagnosis in mechanical systems — Fault power estimation approach

Abstract

A systematic method is introduced to deal with actuator faults in a class of nonlinear mechanical control systems. The presence of the fault is detected by monitoring the fault induced modifications in the control system's energy balance. From the energy deviation the residual generator estimates the power of the fault. For fault isolation and identification the set of fault power pattern signals is defined. Using signal processing methods the elements of this set are compared to the residual signal to determine the characteristics and the magnitude of the fault. The method does not require assumptions on the system's model and it can handle parameter uncertainties. The applicability of the proposed method is shown through mechatronic examples.

A comparative study of energetic model-based fault detection using HBG and COG formalisms

“…A behavioral viewpoint, which incorporates energy and information flow as basis for modeling, is mostly treated like a viable solution. The author introduces an approach that discerns energy and power exchanges induced by the presence of faulty situations. These modifications are thereby calculable from the energy balance of the system under investigation.…”

“…This approach is also able to detect and isolate the faults on the physical parameters of the system. With reference to Marton, a systematic method is introduced to handle actuator faults in a class of nonlinear mechanical control systems. The presence of the fault is detected by monitoring the fault‐induced modifications in the control system's energy balance.…”

“…Assume that this vector can modify the input signal. The faulty system input is then defined by u = u n + f u (10) where u n is the input calculated in nominal case. Afterward, the presence of the fault modifies the energy balance Equation 9, which can be rewritten as…”