Porsche 911 TURBO - 1975 WORSHOP, Руководство пользователя

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48
Controls, Safety, Instruments
Porsche Stability Management
(PSM)
PSM is an active control system for stabilisation of
the vehicle during extreme driving manoeuvres.
The further development of the PSM has improved
the braking functions.
Danger!
f In spite of the advantages of PSM, it is still the
driver's responsibility to adapt his driving style
and manoeuvres in line with road and weather
conditions, as well as the traffic situation.
f
The increased safety that is provided should
not induce you to take greater risks with your
safety. The limits set by the physics of driving
cannot be overcome, even with PSM.
Risks of accident due to inappropriate speed
cannot be reduced by PSM.
Sensors at the wheels, brakes, steering system
and engine continuously measure:
– Speed
– Direction of travel (steering angle)
– Lateral acceleration
– Rate of turn about the vertical axis
– Longitudinal acceleration
PSM uses these values to determine the direction
of travel desired by the driver.
PSM intervenes and corrects the course if the
actual direction of motion deviates from the
desired course (steering-wheel position):
It brakes individual wheels as needed. In addition,
the engine power may be manipulated in order to
stabilise the vehicle.
The events below inform the driver of PSM control
operations and warn him to adapt his driving style
to the road conditions:
– The multi-functional information light on the
instrument panel flashes.
– Hydraulic noises can be heard.
– The vehicle decelerates and steering-wheel
forces are altered as the PSM controls the
brakes.
– Reduced engine power.
– The brake pedal pulsates and its position is
changed during braking.
In order to achieve full vehicle deceleration,
foot pressure must be increased after the
brake pedal has begun vibrating.
Examples of PSM control operations
– If the front wheels of the vehicle drift on a
bend, the rear wheel on the inside of the bend
is braked and the engine power is reduced if
necessary.
– If the rear of the vehicle swings out on a bend,
the front wheel on the outside of the bend is
braked.
– Pre-filling the brake system:
The brake system is prepared for possible
subsequent emergency braking if the acceler-
ator pedal is released suddenly and quickly.
The brake system is pre-filled, and as a result
the brake pads then already slightly touch the
brake discs.
– Brake booster:
In the event of an emergency braking operation
where the pedal force is insufficient, a brake
booster provides the braking pressure neces-
sary for maximum deceleration at all 4 wheels.
Advantages of PSM
– Best possible traction and lane-holding ability
in all driving situations – even on road surfaces
with varying friction.
– The system compensates for undesired
vehicle reactions (Ferraria effect) when the
driver releases the accelerator pedal or brakes
on bends. This compensation functions up to
the maximum lateral acceleration.