Analysis of a Controller for the M61 Movable Gun.
Abstract
The effects of changing control parameters of the movable M61 gun system proposed for the F-15 aircraft are examined using time response and root locus methods. In the course of the analysis, a Fortran IV simulation program, state space model, and gun servo subsystem Z transform are developed. The gun servo subsystem design has little effect on system response. The system settled in under 0.2 sec and had less than 10% overshoot for any open loop gain from 0 to 200/sec and with or without differential pressure compensation. The overall system is stable for a system gain 0 to 39 and exhibits nearly deadbeat responses for a gain of 20. Digital rate feed-forward is required to keep ramp following error below 1 mrad for a 5 deg/sec ramp. Digital filtering improves response and analog low-pass sensor filters with a cutoff of 30 Hz eliminate aliasing while moderately reducing system performance. Computation delays of less than 0.005 sec were found to have negligible effect on the system response. The muzzle response is examined and a compensator, which neglects barrel cluster rotation, is designed to reduce the 50% overshoot and over 2 sec settling time for a step input. This, however, degraded tracking of more realistic (lower frequency content) inputs indicating that a better compensator should be designed or that muzzle response at target acquisition should be allowed to settle before firing. Overall, the movable M61 was found to be an extremely fast gun system, insensitive to most control parameters. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1978
- Accession Number
- ADA081893
Entities
People
- Donald E. Jones
Organizations
- Air Force Institute of Technology