Hyundai Motor Group has developed the world’s first Active Shift
Control (ASC) transmission technology. The innovation optimizes transmission
efficiency by monitoring gear shifts 500 times per second, precisely adjusting
the transmission rotation speed for faster shift times. The new technology will
premiere in the upcoming Hyundai Sonata Hybrid and eventually benefit other
upcoming Hyundai and Kia hybrids.
In a release by Hyndai Media team and made available to OpenLife on July 10,
the ASC applies new control logic software to the Hybrid Control Unit (HCU),
which then controls the electric motor to align the rotational speeds of the
engine and transmission to reduce gear shift time by 30 percent. The technology
also delivers smoother gear changes despite quicker shift times.
“The development of world’s first ASC technology is a remarkable innovation
which incorporates precise motor control to automatic transmission,” said
KyoungJoon Chang, Vice President and Head of Powertrain Control System Group of
Hyundai Motor Group, “It will not only save fuel but also provide a more fun
driving experience for our customers.”
Innovation: Independently Developed Control Logic Software Applied to the
Electric Motor
Conventional hybrid vehicles do not have torque converters in order to further
improve fuel economy as torque converters lose energy during the process of
transmission. Although fuel efficient, such a system also requires longer shift
times to ensure smoother gear changes.
ASC technology allows the hybrid’s electric motor to also take control of gear
shifts by applying new software logic to the Hybrid Control Unit (HCU) to
mitigate issues with slower shift time. The HCU monitors the rotational speed
of transmission with a sensor installed inside the electric motor at 500 times
per second to quickly synchronize the rotational speed with that of engine.
With the synchronization, shift time is reduced by 30% from 500ms to 350ms.
This not only improves hybrid vehicle’s acceleration performance and fuel
economy, but also durability of the transmission by minimizing friction during
gear shift.