The design of the MTA transmission system
for the C514 gearbox fitted on the 1.2 petrol version automates
the controls for the clutch and gear lever for a conventional manual gearbox
through electro-hydraulic type power assistance.
This system:
Improves the performance of components of manual mechanical
transmission.
Avoids the need for the driver to control the clutch pedal
and conventional gearchange control.
Improves driving safety by the control which prevents
driver errors and prevents incorrect manoeuvres of the transmission
system.
Offers the driver a more advanced vehicle interface.
Is a hydraulic power assistance for the gearbox and clutch
which preserves all the advantages of a dry clutch and mechanical
gearbox (weights, strength and reliability, low energy consumption).
Simplifies use and reduces driving fatigue, especially
in cities.
Ensures comfortable or sporty gear changes thanks to the
assistance by advanced control logic.
Does not have a clutch pedal in the interior compartment,
and the control lever is replaced by electrical 'Up/Down/Neutral/Retro'
controls.
It can enable automatic gearchange management in 'AUTO'
mode (by the driver) in two different logics (ECO/NORMAL).
SEMIAUTOMATIC MODE (MANUAL): the driver
manages gear engagement via the lever located in the dashboard.AUTOMATIC MODE (AUTO): the decision to change
gears is delegated to the electronic system, in accordance with
two strategies, the first aiming for driving comfort (NORMAL), the
second aiming to limit fuel consumption (ECO).The signals that allow the operation of
the system reach the control unit via the CAN (Controller Area Network)
and can be grouped together in two main sub-systems, one which includes
the data coming from the gearbox area that makes it possible to
identify the position of the engagement, the selection, the clutch,
the hydraulic kit operating pressure, in addition to the clutch
rotation speed, the other which includes all the signals coming
from the vehicle systems (e.g. engine, braking system) and which
contribute to defining ghe gear change in a way that it precise
and can be repeated.The simple request from the lever for a
higher gear (by moving the lever towards the '+' symbol) or a lower
gear (by moving the lever towards the '-' symbol) allows sporty
and fast or smooth and comfortable gear changes to be made.This operating logic is also activated in
automatic mode: in this way it is possible to produce a personalized
driving style that has smooth driving or saving fuel, especially
in urban traffic as the main ojective.These objectives are reached thanks to the
implementation of the change by means of a hydraulic system capable
of managing the speed of the gear change or the comfort without compromise
thereby always ensuring maximum system performance.Having started the engine, pressing the
brake pedal confirms the presence of the driver in the driving seat
to the system and allows the engagement of first or reverse gear
or, on a slippery surface, second gear for setting off.In addition, to guarantee safety and prevent
undesired gear change requests, with the engine running, if one
of the doors is opened and the driver leaves the driving seat (releasing
the accelerator or brake pedal is interpreted as abandoning the
vehicle) the system engages neutral.The system anticipates errors that could
damage the engine or the gearbox not accepting requests from the
driver and signalling the situation by means of warning messages
in the multifunction display, the malfunction warning light and
two tone horn to advise of emergency situations or remind the driver
of a manoeuvre that is not permitted.There are two operating logics available
in automatic mode: normal and economy. The use of the former has driving comfort
as its aim without adversely affecting the driver's request for
snappy gear changes in all conditions, whilst for the economy logic the
aim is to achieve the longest gear for the vehicle conditions to
ensure that fuel consumption is contained whilst maintaining driveability
and driving comfort at maximum levels.In both logics the system lengthens the
rotation speed with the engine supplying the maximum torque or power
to the higher ratio. When using this mode the system is also
capable of recognizing the gradient of the road: a software algorhithm
recognizes the increase in gradient and modifies the gear change point
so that the compromise between the driver's requirements, the road
conditions and the situation of the vehicle (speed and engine rpm)
is always optimum.Another feature of the system is recognizing
the deceleration of the vehicle and adapting the downwards shift
depending on the level of deceleration: in this way in manual mode the
system allows a downwards shift when in sports mode the driver request
a lower gear to take a curve briskly and in automatic mode it anticipates
the downshift to allow the driver to have the most suitable gear
available to maintain the comfort level or fuel saving requested.