Accession Number : ADP009081

Title :   Design of Robust Structural Controllers for Gun-Turret Systems.

Corporate Author : MISSOURI UNIV-ROLLA DEPT OF ELECTRICAL ENGINEERING

Personal Author(s) : Rao, Vittal S. ; Mattice, Michael S. ; Coleman, Norman P., Jr.

Report Date : SEP 1993

Pagination or Media Count : 15

Abstract : Improvements in robust performance of gun-turret system mounted on helicopters, can significantly enhance the mission capabilities of light attack helicopters. A significant research effort has been directed toward the design and implementation of controllers which can guarantee the stability and performance. Some of the specific gun-turret problems are impulse loads near the first flexible mode of the system, time-varying friction in the recoil slider, lack of barrel tip position sensors, presence of non-linear elements, and lack of proper mathematical models of the gun-turret systems. One of the major sources of fire control error is due to the excitation of several structural modes by gun firing. Designing controllers for such system whose mathematical model is subject to uncertainties is an interesting and challenging problem. To design active controllers for flexible gun systems, a mathematical representation of the system is needed. We have derived mathematical models of gun-turret systems by analytical methods and model validation is accomplished by using structural identification methods. In order to accomplish simplicity in the controller implementation, we have derived reduced order models by using optimal projection methods. To account for uncertainties in the structural models and to accomplish good closed loop system performance and sensor noise suppression properties, we have developed robust control design methodologies for gun-turret systems. The reduced order models are utilized in the design of robust controllers. We have utilized a modified linear quadratic Gaussian with loop transfer recovery (LQG/LTR) robust control design methodology for accommodating the limited control force provided by the actuators.

Descriptors :   *GUN TURRETS, *ROBOTICS, *FIRE CONTROL SYSTEMS, ACTUATORS, ATTACK HELICOPTERS, CLOSED LOOP SYSTEMS, CONTROL, ERRORS, EXCITATION, GUARANTEES, MATHEMATICAL MODELS, METHODOLOGY, MISSIONS, NOISE, RECOIL, RECOVERY, STABILITY, SUPPRESSION, TRANSFER, UNCERTAINTY, VALIDATION.

Subject Categories : Fire Control and Bombing Systems
      Human Factors Engineering & Man Machine System
      Helicopters
      Guns

Distribution Statement : APPROVED FOR PUBLIC RELEASE