If m_speed_pid_set_rpm is allowed to exceed foc_openloop_rpm before index is found,
then there will be a jump in torque when index is found.
If m_speed_pid_set_rpm is allowed to exceed [l_min_erpm, l_max_erpm] then there is
a wind up effect since it will take time for m_speed_pid_set_rpm to return to valid
range due to ramp limit.