Part location algorithms for an Intelligent Fixturing System Part 2: algorithm testing and evaluation

Abstract An Intelligent Fixturing System (IFS) is currently being developed to hold a family of cylinder heads for machining operations. This system incorporates a Part Location System (PLS) to locate the workpiece reference frame of a cylinder head relative to a pallet. This two-part paper describes the development and evaluation of various part location algorithms that have been created for this application. Part 2 of this paper describes a series of simulation experiments that was carried out to assess the accuracy and computation speed of the SeQuential Least Squares (SQLS) algorithm, the SiMultaneous Least Squares (SMLS) algorithm, and the SQLS-SMLS (fixed cd) algorithm. The results of this study reveal that the SQLS algorithm is fast to execute, but its accuracy is very sensitive to random variations in the coordinate data. Alternatively, the SMLS algorithm is insensitive to random variations in the coordinate data but is computationally more expensive to execute. Furthermore, its accuracy is sensitive to bias errors in the chordal distance between the dowel holes. Only the SQLS-SMLS (fixed cd) is insensitive to both types of variations.