Some linear and nonlinear aspects of hot gas servo design

Gas servos are considered from a feedback analysis standpoint with emphasis on systems such as would be most suitable for missile application. Linearized equations are presented for the case where the piston is operating off-center. The basic stability and response problems are investigated and some of the characteristics of acceleration, pressure, and transient pressure feedback are considered. The use of a thin plate orifice for compensation use is considered and a quasi-linear analysis is carried out in order to obtain a better feel for this type of operation. A criterion for the presence and severity of a jump resonance is derived and applied to certain gas servo feedback configurations. Limiting elsewhere in the system is investigated as a means by which the jump resonance caused by saturation of the valve might be avoided.