Report of the Second Piloted Aircraft Flight Control System - Acgsc.org

For the case with Minite campressibility, the above open loap transfer
functian became8
Input motion is coupled to output motion only because of the riscons
drag of the valve an the cylinder, The system is no longer a Gem
position error device, Physically, the use of the relationship of
equation (30) appears when two hydraulic ayatans are connected in parallel,
with the power to one system shut down, or on a single actuator installation
with per off, If there is no viecaus friction caupllng between
valve and cylinder, the transfer function beames zero, art them is no
motion trandtted fmm input to output,
COUPLING SPRING -4 w - he situation occasio- mires
where backlash occurs between the cylinder and the surface load. It is
then desirable to investigate the stability of the systaa within the
backlash region, though it must be remembered that stability inside the
backlash region does not necessarily rule out the possibility of a limit
cycle occurring due primarily to the backlash,
he open loop transfer function with .A =a then becaer :
which, when Cp = o reduces to