moment, positioning accuracy is fairly high, and ineffective travel is small
enough. In this way, the control surface can be locked in zero position
reliably and accurately.
4. Resistance to counter manipulation. In order to reduce the aerodynamic
moment of the control surface, modern air defense missiles will work in
the counter-maneuvering state, so the rudder system must have the
counter-maneuvering ability. The key here is to select the right type of
steering gear, in which the hydraulic steering gear will be optimized. Flight
tests show that the control surface of an air defense missile with “compensated” or “overcompensated” aerodynamic configuration is in an countermaneuvering control state in the subsonic and transonic flight phases, and the
rudder system of the air-cooled rudder is out of control and divergent, while
the rudder system of the hydraulic rudder can still work normally.
(2) Steering Engine
1. Steering engine bandwidth. It is decided by the frequency bandwidth distribution of the rudder system that it should be compressed as much as
possible. The research and development practice has proved that over-wide
bandwidth necessarily requires an increase in the speed gain of the steering
gear, thus significantly increasing the power of steering gear and its energy.
Over-wide bandwidth is susceptible to electronic noise and other interference. Under some incentives, the control surface will even produce
self-excited oscillation, which will cause system instability.
2. Steering speed. It mainly depends on the frequency bandwidth of the
steering gear and the equivalent force arm of the mechanism. In addition to
the special cases such as counter- maneuvering of control surface and static
instability control of missile, the steering gear is required to have a larger
load speed, and the steering and damping loops of control surface are
respectively provided with deep negative feedback. Normally, the speed of
the steering gear should not be too high to ensure the stability of the system,
reduce the energy power, and obtain the appropriate equivalent force arm of
the mechanism.
3. Steering engine moment. It should be able to overcome the comprehensive
load moment such as hinge moment, inertia moment, damping moment, and
friction moment of the control surface, and provide a certain speed of the
control surface under the rated load moment. Even under the action of the
maximum hinge moment, for reliable operation, the rudder should maintain
the minimum control surface speed.
4. Load characteristic analysis. Figure 9.13 shows the load characteristic curve
of the control surface of a typical aerodynamic layout air defense missile
with full-motion wing. Its main characteristic is the elastic load. The trajectory of the velocity–moment characteristic curve is a rotating dislocation
ellipse with a slightly inclined axis and slightly distorted. The arrow
direction indicates the main characteristics of the load. For most air defense
missiles controlled by air rudder, stiffness (i.e., hinge moment) plays a
84
9 High-Temperature and High-Speed Gas Turbine Pump …
enough. In this way, the control surface can be locked in zero position
reliably and accurately.
4. Resistance to counter manipulation. In order to reduce the aerodynamic
moment of the control surface, modern air defense missiles will work in
the counter-maneuvering state, so the rudder system must have the
counter-maneuvering ability. The key here is to select the right type of
steering gear, in which the hydraulic steering gear will be optimized. Flight
tests show that the control surface of an air defense missile with “compensated” or “overcompensated” aerodynamic configuration is in an countermaneuvering control state in the subsonic and transonic flight phases, and the
rudder system of the air-cooled rudder is out of control and divergent, while
the rudder system of the hydraulic rudder can still work normally.
(2) Steering Engine
1. Steering engine bandwidth. It is decided by the frequency bandwidth distribution of the rudder system that it should be compressed as much as
possible. The research and development practice has proved that over-wide
bandwidth necessarily requires an increase in the speed gain of the steering
gear, thus significantly increasing the power of steering gear and its energy.
Over-wide bandwidth is susceptible to electronic noise and other interference. Under some incentives, the control surface will even produce
self-excited oscillation, which will cause system instability.
2. Steering speed. It mainly depends on the frequency bandwidth of the
steering gear and the equivalent force arm of the mechanism. In addition to
the special cases such as counter- maneuvering of control surface and static
instability control of missile, the steering gear is required to have a larger
load speed, and the steering and damping loops of control surface are
respectively provided with deep negative feedback. Normally, the speed of
the steering gear should not be too high to ensure the stability of the system,
reduce the energy power, and obtain the appropriate equivalent force arm of
the mechanism.
3. Steering engine moment. It should be able to overcome the comprehensive
load moment such as hinge moment, inertia moment, damping moment, and
friction moment of the control surface, and provide a certain speed of the
control surface under the rated load moment. Even under the action of the
maximum hinge moment, for reliable operation, the rudder should maintain
the minimum control surface speed.
4. Load characteristic analysis. Figure 9.13 shows the load characteristic curve
of the control surface of a typical aerodynamic layout air defense missile
with full-motion wing. Its main characteristic is the elastic load. The trajectory of the velocity–moment characteristic curve is a rotating dislocation
ellipse with a slightly inclined axis and slightly distorted. The arrow
direction indicates the main characteristics of the load. For most air defense
missiles controlled by air rudder, stiffness (i.e., hinge moment) plays a
84
9 High-Temperature and High-Speed Gas Turbine Pump …