Ph.D. Proposal Presentation by Laine Mears
Monday, March 29, 2004

(Dr. Tom Kurfess, Chair)

"Design of an Automatic Centering System for Finished Bearing Ring Measurement"


Precise sample measurement of finished bearing rings in manufacturing practice is carried out by placing the finish ground ring onto a table mounted to a precision spindle, manually centering the ring during rotation of the table, then automatically measuring the ring roundness. This method is costly due to the relatively long centering process (about 15% of total cycle time).

The focus of this proposal is automating the initial centering process of the ring. This is motivated in order to reduce the required time for centering, which will reduce cost and allow for a higher sampling rate in manufacturing.

This proposal addresses key issues required to automate the current skilled manual centering process, namely

1) initial system modeling including that of two-dimensional part sliding dynamics and friction
2) real-time system identification of the response dynamics.
3) development of fine positioning control, first for a single degree of freedom system then with the ring rotational component introduced
4) adaptive parameterization of the developed model to apply a single control model to a family of rings given sufficient input parameter knowledge

The centering research addresses mathematical model development, control law development, and system identification and validation first through simulation, then through physical prototyping. Measures of success are centering time reductions from current datum values (manual centering process) and achievable repeatable centering tolerance.

It is anticipated that the proposed research will advance knowledge in the fields of fine position control and parametric dynamic control, with immediate practical applications in finish metrology and workholding in manufacturing.