Following the discussions of the last section,
the system parameters before and after shift are
different. The degree of freedom during shift also
increases by one compared with the degree of
freedom after the shift. Moreover, several variables
such as input turbine torque and load, etc.
can vary with time depending on the operating
conditions.
For the passenger comfort, a smooth transient
during shift is essential. To this end, one has to
enforce the system to progress from the initial
conditions (before shift) to the final states (after
shift) without abrupt variations. During this
process, a dynamic shift condition, Eq. (14b),
should be met. For components' longevity, shiftmust be accomplished within a suitably short
period. Recalling these facts, we seek how to
make smooth transient within a designated shift
completion time t.