Active control of machine tool vibrations in external turning operations

1
Active control of machine tool vibrations in
external turning operations

• Authors L. Andren, L. Hakansson, and I. Claesson
• Published June 2003
• Presentor Scott Peterson
• Date Oct 29, 2008

2
Introduction

• Function of Paper
• The purpose of this paper is to validate a method
  of vibration reduction in external turning
  operations utilizing a system which combines an
  actuator control by an algorithm generated by an
  accelerometer to counteract and dampen the
  vibrations.

3
Introduction

• Why is this important?
• Vibrations during a cutting operation affect the
  accuracy of the machining, which in turn affects
  the surface finish. Severe noise is also an
  important factor which is induced by tool holder
  vibrations.

4
Introduction

• References

5
Models and design Principles

• This process relates to many areas of the course.
  By reducing vibrations we improve the surface
  finish, something very pertinent to
  manufacturing. It also affects the life of the
  cutting tool because a tool operating under more
  vibrations will experience more stresses and fail
  sooner.

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Models and design principle

• Parameters and Design
• -Cutting trials performed on a
• MAZAK 250 quickturn lathe
• -Piezoceramic actuator is able
• To apply loads up to 1000N
• -Workpiece material is Chromium Molybdenum nickel
  steel
• -cutting speed 80m/min
• -depth 0.9mm
• -feed rate 0.25mm
• Workpiece diameter gt 100mm (negligible workpiece
  vibrations)

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Models and design principles

• Challenges
• Reduces stiffness (20)
• Harsh environment for electronics
• Cutting operation has non-stationary properties
• Actuators excite the structure such that the
  vibration level is minimized.

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Models and Design Principles

• Control System Filtered X LMS algorithim

9
Results

• The tool holder is attenuated by aprx 40dB using
  the active control system.

10
Results

• The finish of the surface is improved
  significantly

11
Conclusions

• Practical for industrial use?
• Technical advancement?
• Industries most impacted?

12
Conclusions

• Questions?