0
Research Papers

Cantilever Beam Design for Projectile Internal Moving Mass Systems

[+] Author and Article Information
Jonathan Rogers, Mark Costello

School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA 30318

J. Dyn. Sys., Meas., Control 131(5), 051008 (Aug 18, 2009) (11 pages) doi:10.1115/1.3155017 History: Received October 29, 2008; Revised May 04, 2009; Published August 18, 2009

Internal masses that undergo controlled translation within a projectile have been shown to be effective control mechanisms for smart weapons. However, internal mass oscillation must occur at the projectile roll frequency to generate sufficient control force. This can lead to high power requirements and place a heavy burden on designers attempting to allocate volume within the projectile for internal mass actuators and power supplies. The work reported here outlines a conceptual design for an internal translating mass system using a cantilever beam and electromagnetic actuators. The cantilever beam acts as the moving mass, vibrating at the projectile roll frequency to generate control force. First, a dynamic model is developed to describe the system. Then the natural frequency, damping ratio, and length of the beam are varied to study their affects on force required and total battery size. Trade studies also examine the effect on force required and total battery size of a roll-rate feedback system that actively changes beam elastic properties. Results show that, with proper sizing and specifications, the cantilever beam control mechanism requires relatively small batteries and low actuator control forces with minimum actuator complexity and space requirements.

Copyright © 2009 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

The ITM-beam projectile

Grahic Jump Location
Figure 2

Zoom view of the ITM-beam system

Grahic Jump Location
Figure 3

Altitude versus range for example trajectory

Grahic Jump Location
Figure 4

Cross range versus range for example trajectory

Grahic Jump Location
Figure 5

u Velocity versus time for example trajectory

Grahic Jump Location
Figure 6

Roll rate versus time for example trajectory. The thick lines represent high frequency oscillations, which occur only for the ITM-beam and translating mass case.

Grahic Jump Location
Figure 7

Selected time history of ITM displacement from projectile centerline

Grahic Jump Location
Figure 8

Segment of current versus time for ITM-beam actuators

Grahic Jump Location
Figure 9

Maximum displacement versus beam length

Grahic Jump Location
Figure 10

Average force required versus beam length

Grahic Jump Location
Figure 11

Roll rate versus time for example simulation

Grahic Jump Location
Figure 12

Average force required versus torsional spring constant partial flight profile

Grahic Jump Location
Figure 13

Average power required versus torsional spring constant partial flight profile

Grahic Jump Location
Figure 14

Total charge required versus torsional spring constant partial flight profile

Grahic Jump Location
Figure 15

Average force required versus torsional spring constant full flight profile

Grahic Jump Location
Figure 16

Average power required versus torsional spring constant full flight profile

Grahic Jump Location
Figure 17

Total charge required versus torsional spring constant full flight profile

Grahic Jump Location
Figure 18

Current through actuators versus time for example full flight trajectory

Grahic Jump Location
Figure 19

Torsional spring constant versus time for roll-rate feedback system, ζ=0.05

Grahic Jump Location
Figure 20

Total charge required versus damping ratio for constant and variable kT cases

Grahic Jump Location
Figure 21

Translating mass projectile schematic

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In