Hierarchical Optimal Force-Position Control of a Turning Process

Abstract

Machining process control technologies are currently not well integrated into machine tool controllers and, thus, servomechanism dynamics are often ignored when designing and implementing process controllers. In this brief, a hierarchical controller is developed that simultaneously regulates the servomechanism motions and cutting forces in a turning operation. The force process and servomechanism system are separated into high and low levels, respectively, in the hierarchy. The high-level goal is to maintain a constant cutting force to maximize productivity while not violating a spindle power constraint. This goal is systematically propagated to the lower level and combined with the low-level goal to track the reference position. Since the only control signal (i.e., motor voltage) resides at the lower level, a single controller is designed at the bottom level that simultaneously meets both the high- and low-level goals. Simulations are conducted that validate the developed methodology. The results illustrate that the controller can simultaneously achieve the low-level position tracking goal and the high-level force-tracking goal.

Department(s)

Mechanical and Aerospace Engineering

Keywords and Phrases

Aggregation; Force Control; Hierarchical Optimal Control; Hierarchical Optimal Force-Position Control; Hierarchical Systems; High-Level Force-Tracking Goal; Low-Level Position Tracking Goal; Machining Force Control; Optimal Control; Position Control; Process Control; Servomechanism Motions; Servomechanism Position Control; Servomechanisms; Spindle Power Constraint; Turning (Machining); Turning Process; Turning Processes

International Standard Serial Number (ISSN)

1063-6536

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

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

Publication Date

01 Jan 2005

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