There has been a tremendous amount of research in machine tool servomechanism control, contour control, and machining force control; however, to date these technologies have not been tightly integrated. This paper develops a hierarchical optimal control methodology for the simultaneous regulation of servomechanism positions, contour error, and machining forces. The contour error and machining force process reside in the top level of the hierarchy where the goals are to 1) drive the contour error to zero to maximize quality and 2) maintain a constant cutting force to maximize productivity. These goals are systematically propagated to the bottom level, via aggregation relationships between the top and bottom-level states, and combined with the bottom-level goals of tracking reference servomechanism positions. A single controller is designed at the bottom level, where the physical control signals reside, that simultaneously meets both the top and bottom-level goals. The hierarchical optimal control methodology is extended to account for variations in force process model parameters and process parameters.

Meeting Name

2005 American Control Conference (2005: Jun. 8-10, Portland, OR)


Mechanical and Aerospace Engineering

Keywords and Phrases

Contour Control; Force Control; Hierarchical Optimal Force-Position-Contour Control; Machine Tool Servomechanism Control; Machine Tools; Machining; Machining Force Control; Machining Process Control; Optimal Control; Position Control; Process Control; Reference Servomechanism Position Tracking; Servomechanisms

International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2005 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jun 2005