BMW Dynamic Damping Control
Making motorcycles better, safer, and
more fun to ride with innovative developments has
been one of the BMW Motorrad core competences for
decades. As the leader in this technology, BMW Motorrad
presents new solutions in quick succession that usually
soon become indispensable in series motorcycles. Now
a new step in development is in the offing: the semiactive
suspension control system Dynamic Damping Control,
in short DDC.
BMW Motorrad – competence
in suspension innovations and control systems.
As early as 1986, BMW Motorrad achieved
a milestone in suspension technology by launching
the Paralever swingarm, an innovation that considerably
improved rear suspension and the transfer of forces.
In 1993, the freshly launched opposed twin “boxer”
engine series was the first to be fitted as standard
with a front suspension system that operated independently
of the rear known as Telelever. Yet another revolutionary
step in suspension technology was taken in 2005, when
the Duolever offering extreme torsional rigidity for
the front wheel was launched.
Bikers were also able to benefit early
from pioneering innovations in drive control. In 1988,
with the launch of ABS in the BMW K1, BMW Motorrad
presented the first antilock brake system to be fitted
as standard on motorcycles.
Since 2007, the automatic stability
control system ASC has been preventing the rear wheel
from spinning out of control. In 2009 there followed
Dynamic Traction Control (DTC) which also analyses
inclination, a first on a series production motorcycle.
And BMW Motorrad has always been that
one step ahead in suspension control systems as well.
2004 saw the advent of ESA, the electronic suspension
adjustment system, which allowed the rider to adjust
suspension elements at the push of a button –
also a first on series production motorcycles.
In 2009, the successor system ESA II
went a step further and was the first to provide spring
The next logical step – semiactive suspension
The next logical step in the development
of suspension and control systems is taking concrete
shape. The next stage of evolution in this field is
the automatic adjustment of suspension elements to
diverse operating conditions like varying road surfaces
or certain manoeuvres. BMW Motorrad achieves this
through Dynamic Damping Control DDC.
Analogous technologies have been used
with great success in BMW automobiles, for instance
the BMW M3 and BMW M5, for years now. This gives rise
to valuable synergy effects for internal developments.
challenge: adapting the system to the requirements
of motorcycle physics and integrating this in the
relevant control systems.
The evolution: from ESA II
BMW Motorrad announced the considerable
progress it had made in adapting its systems to varying
payload and road surfaces by launching ESA II, the
new electronic suspension adjustment system. This
lets the rider adjust the Duolever, Telelever, and
Paralever damping properties as well as the rear wheel
spring rate or its "tightness", all at the
convenience of pressing a button.
The characteristics the rider can select
for suspension and damping provide a range of tuning
and payload settings for all road conditions that
is yet to meet its match. In conjunction with the
three tuning variants "Comfort", "Normal",
and "Sport", ESA II therefore opened up
a new dimension of ride stability with the best response
in all operating and payload configurations.
In this form, ESA II was the first
electronic suspension tuning system worldwide to provide
these configurations on motorcycles at all. With the
object of achieving even greater stability and safety
in riding response, Dynamic Damping Control DDC goes
a step further. DDC is a semiactive suspension system
which reacts automatically to manoeuvres like braking,
accelerating, and cornering on various road surfaces
and analyses the situational parameters provided by
sensors to set the correct level of damping at electrically
actuated proportional damping valves.
DDC is linked to the traction control
system DTC and ABS via the CAN bus. The system recognises
the control activities by the other systems and adapts
the damping as the situation requires. The adjustments
to damping depend on whether the springs are compressing
or rebounding, with each process being controlled
The damping is adjusted at an electrically
actuated, proportional damping valve that features
a variable ring gap and therefore variable flow cross
section for the damper oil. The inversely proportional
adjustment to flow rate and pressure gives rise to
a change in damping force within milliseconds to adapt
to new conditions.
Unlike ESA II, the dynamic damping
control system DDC does not make use of characteristic
curves, but characteristic maps that provide the optimal
damper tuning within a defined range. Selected at
the press of a button, three characteristic maps for
the basic configurations "Comfort", "Normal",
and "Sport" let the rider realise his own
wishes on this system too. As known from ESA II, the
selected configuration is displayed in the instrument
Analogously to ESA II, DDC
also features variable spring rates.
The operating principle of
A number of examples quickly provide
some insights into the advantages for certain riding
situations. Before the rider sets off, activating
the ignition first initiates the system check and
the flow of information from the engine control, ABS
control unit, sensor box (DTC), and the spring travel
sensors to the DDC control unit. This appears on the
display in the instrument panel.
When the motorcycle sets off, the valves
in the front and rear dampers are actuated only marginally
(supplied with power) when the speed exceeds a definable
value. When the rider accelerates, e.g. when leaving
the city limits, the valve in the rear strut is actuated
more strongly owing to the changes in dynamic wheel
load distribution and in the drive torque. Once the
target speed has been reached, valve actuation drops
back to its original level (less power supply than
setting off). Information flows from the throttle
grip via engine control to the DDC control unit, and
from there to the damping valves.
When the rider takes a series of corners,
both damping valves are actuated more strongly with
increasing inclination – starting from the low
power supply – until the vertex is reached.
When the vehicle returns upright between two corners,
the actuation of the two damping valves constantly
drops to the original power level with decreasing
inclination. When the motorcycle turns into the second
corner, valve actuation again rises proportionally
to the angle of inclination and again drops from the
vertex value. Information flows from
the sensor box (DTC) to the DDC control unit, and
from there to the damping valves.
When the motorcycle brakes, e.g. at
a rail crossing, the actuation of the front damping
valve increases proportionally to the deceleration
so that the damping forces and therefore riding stability
increase as a result. In this case, Dynamic Damping
Control DDC analyses both the dynamic phase of braking,
until constant deceleration and wheel load distribution,
and the subsequent static phase.
Once the adjusted speed has been reached
(here for passing over the rail crossing), the power
supply and therefore the actuation return to their
original values. At the same time, information flows
from the hand brake pump on the handlebar to the ABS,
and from there via the DDC control unit to the valves.
When the motorcycle is passing over the rail crossing
(here representing all types of uneven road surfaces),
the valves in the front and rear dampers are actuated
(powered) proportionally to the respective compression
this case, information flows the front and rear spring
travel sensors via the DDC control unit to the valves.
When the motorcycle is finally brought
to a stop, the valves are first actuated as in the
braking process described above. As soon as the motorcycle
is stationary, the power to the valves and therefore
their actuation are deactivated. The benefits of the
dynamic damping control system DDC are obvious. Within
the shortest of times the system evaluates a huge
amount of information and selects the high precision
suspension configuration best suited to the situation.
This provides a considerable boost to active riding
comfort, and – not least of all – riding
The suspension damping system DDC will
be introduced to the first BMW Motorrad series motorcycles
in the near future.