A cabin pressure control system (CPCS) software control logic modification
may boost the voltage applied to a motor by applying a duty cycle offset
to compensate for asymmetric motor loading. The motor may be part of an
open-loop system for operating a butterfly valve that may regulate
outflow from the aircraft cabin. In CPCS applications, the loading on the
butterfly valve is unidirectional due to a mechanical spring and
pneumatic loading, thus, causing asymmetric loading to the motor. By
boosting the motor voltage when the motor is required to act against the
asymmetric load, CPCS performance and robustness may be improved.