Adjusted Least Squares Approach for Diagnosis of Ill-Conditioned Compliant Assemblies
نویسندگان
چکیده
Least squares (LS) estimation has been extensively used for parameter identification and model-based diagnosis. However, if ill-conditioning is present, the LS estimation approach tends to generate imprecise results and thus impacts the diagnostic performance. In this paper, an adjusted least squares approach is proposed to deal with the illconditioning problem in the diagnosis of compliant sheet metal assembly process. The adjusted LS approach is able to overcome the ill-conditioning and give precise results for certain linear combinations of the faults. Simulations and industrial case study are conducted to compare the diagnostic performance of the adjusted and regular LS approach. In addition, a two-stage assembly model is developed for further fault isolation with inclusion of additional measurement information. @DOI: 10.1115/1.1365116#
منابع مشابه
A numerical approach for solving a nonlinear inverse diusion problem by Tikhonov regularization
In this paper, we propose an algorithm for numerical solving an inverse non-linear diusion problem. In additional, the least-squares method is adopted tond the solution. To regularize the resultant ill-conditioned linear system ofequations, we apply the Tikhonov regularization method to obtain the stablenumerical approximation to the solution. Some numerical experiments con-rm the utility of th...
متن کاملRegularization of Large-scale Ill-conditioned Least Squares Problems Regularization of Large{scale Ill{conditioned Least Squares Problems
Ill{conditioned problems arise in important areas like geophysics, medical imaging and signal processing. The fact that the ill{cond-itioning is an intrinsic feature of these problems makes it necessary to develop special numerical methods to treat them. Regularization methods belong to this class. The lack of robust regularization methods for large{scale ill{cond-itioned problems motivated thi...
متن کاملMulti-Level Approach to Numerical Solution of Inverse Problems
Mathematical modeling of an engineering system often leads to such formulations for which one can not obtain a closed form solution/analysis, and thus numerical methods are to be used. In the process, we need to transform the system from an infinite dimensional space to a finite dimensional one(discretization). The result is usually a system of linear equations[5] for which the linear least squ...
متن کاملEffects of Ill-conditioned Data
An ill-conditioned least squares (LS) problem has a solution which may be highly sensitive to small perturbations in the data. This 1,aper presents sensitivity results for the LS weight vector of an all-zero adaptive equalizer in an ill-conditioned signal environment. The ill-conditioned data results from severe amplitude distortion introduced by the data channel.. Specifically, a theoretical u...
متن کاملNew Fast Algorithms for Structured Linear Least Squares Problems
We present new fast algorithms for solving the Toeplitz and the Toeplitz-plus-Hankel least squares problems. These algorithms are based on a new fast algorithm for solving the Cauchy-like least squares problem. We perform an error analysis and provide conditions under which these algorithms are numerically stable. We also develop implementation techniques that signiicantly reduce the execution ...
متن کامل