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.


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)


Document Type

Article - Journal

Document Version

Final Version

File Type





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

Publication Date

01 Jan 2005