ABSTRACT
This chapter summarizes the specification and implementation issues of time-varying, momentarily static residual generators. It describes the difficulties with the popular additive representation. The equations and imply a direct representation of parametric faults and modeling errors. A similar representation can be applied in the framework of state-space models. The design of residual generators for parametric faults and model errors follows the pattern of design for additive faults and disturbances. The fault response may be structured or directional. Since modeling errors are considered as parametric disturbances, decoupling from them is included in the specification, whether structured or directional, as zero disturbance responses. When the fault detection and isolation algorithm is designed with unit diagonal response to parametric faults then the residuals are, in fact, estimates of the parameter changes. If some of the faults and disturbances are additive while others are multiplicative then, in general, the convenient linear transformation machinery breaks down.
