FACTfile - Fiat Grande Punto - Page 4

The best safety in its segment

Fifteen thousand hours of calculations, 60 crash tests, one hundred simulations with a Hyge sled and two hundred tests on components and subsystems. These numbers underline the commitment that went into making the Fiat Punto one of the safest cars, not only in its segment but in the entire world car market, since the model represents the state of the art where passive safety systems are concerned.

Total protection, starting from the specific safety features: up to 7 airbags, two of which are of the Multistage type (six are standard on the Dynamic and Emotion specifications); three-point seat-belts with pretensioners and load limiters, five head-restraints and the FPS fire prevention system. The chassis is also new, designed specifically to absorb impact more efficiently. And the bodywork, the bonnet, the doors and the facia crossbeam all play their part in protecting occupants. Nor must we forget the contribution in terms of passive safety from elements such as the seats or the steering column, which were designed taking into account their behaviour in the event of an accident.

The Smart 2 Airbag system
Complete protection, intelligent protection. In the event of head-on impact, occupants are protected by an innovative restraint system known as the 'Smart 2 Airbag', because it is able to adapt the activation parameters automatically to the severity of an accident. Starting with the two front airbags for the driver and passenger, which have a new, different functioning logic. Until now, when the airbags were activated, they have always inflated simultaneously and up to their maximum size, which was established to safeguard occupants during the most serious impact. The Grande Punto on the other hand, adopts dual stage front airbags; when impact is of medium intensity, the system only activates the first stage; but with very strong impact, the control unit activates both stages. The two stages can also be activated with different sequences according to the type of impact. In any case, the bridles inside the bags guarantee that the maximum dimensions and the shape that the cushions assume are as non-invasive as possible for the passengers. Obviously the front passenger bag can be deactivated by the menu on the control panel, so that an infant can be carried in a special seat facing backwards (the pretensioner remains active).

The sensors of the Smart 2 Airbag also control the activation of the seat-belt pretensioners. The Grande Punto fits inertia reel front seat-belts with pretensioners and load limiters. If impact occurs, the electronic pyrotechnical pretensioner retracts the belt in a few thousandths of a second, so that it grips the body perfectly. The load limiters are inside the front reels, and they give in a controlled manner to meter the effort exercised by the belt on the shoulders of the person wearing it.

The control unit and the sensors
The Grande Punto is fitted with all the most advanced passive safety devices available. A sophisticated "nervous system" has been developed to control them, piloted by an electronic control unit in the front tunnel. This unit receives the signals from the various sensors positioned around the car (as well as those inside the control unit itself) and on the basis of these decides how many and which devices must be activated. This is why the system as a whole behaves in an 'intelligent way'. It is not activated when, in spite of the impact, there is no danger that the occupant will hit against the sides of the car. It recognises the stress that is not derived from impact. It also functions if there is a blackout in the electrical system. Making all this possible, takes extremely sophisticated functioning logics and measurement terminals. Like the CSA (Crash Severity Algorithm) which recognises the severity of the impact and controls the multistage front airbags; or the sensor that detects the presence of a front passenger and may warn the user to fasten his seat-belt with a beep or a telltale on the instrument panel. Or the decentralised sensor that detects head-on impact, and the ECS (Early Crash Sensor), an auxiliary device that is positioned in the front structure of the car and allows the control unit to anticipate the activation of the front airbags; unlike a traditional system, it allows them to unfold completely before the occupants start to move forward towards the steering wheel or the facia.

The curtain bags and sidebags
The former are airbags designed to inflate downwards along the windows, to protect occupants' heads in a side-on collision. The curtain bags adopted on the Grande Punto are more protective than other systems (because they always assume the correct position), inflate faster and are less invasive for passengers. They open from the top down and their movement cannot cause secondary injury to the occupants' arms.

They also effectively protect the heads of both front and rear passengers because they cover the whole windows and guarantee protection even if the car overturns. The two bags (one for the left and one for the right) are positioned underneath the roof longitudinals, folded into a closed compartment. At the appropriate moment, the cover folds, allowing the bags to inflate and descend.

To protect the pelvis and chest of front seat passengers in a side-on collision, the Grande Punto also provides two sidebags built into the squab of the front seats, where they protect the occupants better, regardless of their stature, position or seat adjustment.

Driver's knee-bag (optional)
The area under the steering column has always been the most dangerous for the knees, but it is rendered innocuous both by the addition of the knee-bag and by a new position for the steering lock, which has allowed the ignition key to be moved from its usual position.

The most stringent tests for total protection
To verify the effectiveness of the combined protection system developed for the new model, the technicians of the Fiat Safety Centre subjected the new model to all possible high speed collision situations. They then compared the results with the structural and biomechanical parameters envisaged by some of the world's strictest legislation. The following results were obtained.

Head-on impact
The Grande Punto scored extremely well in two different types of test. The first is carried out at a speed of 64 km/h against a deforming barrier to simulate a head-on impact between two cars; the second envisages a crash at 56 km/h against a fixed, rigid barrier. Thanks to the strong structural architecture and the use of high energy absorption materials, on the Grande Punto the intrusion levels of these tests are extremely limited and allow all the doors to open, without generating significant inertia stress on the occupants because it is efficiently absorbed by the Smart Airbag system. And finally, in the event of head-on impact, the items in the Grande Punto luggage compartment do not hit the passengers.

Side-on impact
Two internationally recognised tests underline the new model's ability to guarantee the safety of the front and rear passengers even in the event of a high speed side-on impact. The first is that of 'impact against a deforming barrier', which simulates a collision at 50 km/h between two cars at a 90° angle. The Grande Punto scores extremely well, thanks to the protection given to the pelvis by the sturdy bodyshell structure, to the abdomen and chest by the combined action of the sidebags and door panels, and to the head by the curtain bags. The second test is that of 'side-on impact against a post', one of the most dangerous for any motorist.

Rear impact
From a structural viewpoint, during rear impact tests attention is focused on containing the deformation of the passenger compartment and preventing damage to the fuel tank which could provoke a fire. From a biomechanical viewpoint, efforts are concentrated on protecting the occupant, preventing the seat from collapsing and minimising any injury, particularly to the neck and head which are usually the parts under the greatest stress.

Pedestrian protection
The front of the Grande Punto was designed bearing in mind the need to protect pedestrians. The lines are smooth and rounded and there are no protruding elements that could be dangerous to a pedestrian. The large surface of the bonnet minimises the risk of a pedestrian's head coming into contact with the rigid front pillars. The most unyielding components inside the engine bay are positioned at a sufficient distance from the bonnet to allow the 'skin' of the bonnet to absorb at low levels the energy generated by impact with the pedestrian's head.

Protection of children
The new model features all the devices that ensure that children travel in complete safety. The main devices that make this effective are the Isofix attachments on the rear seat and the possibility of deactivating the passenger airbag from the onboard computer.

Protection against fire
From the bodyshell to the various components, the Grande Punto was designed and built to meet the latest and strictest internal Fiat standards in the field of fire safety. For example, the adoption of the Fire Prevention System which, in the event of impact above a certain intensity, immediately blocks the electric pump in cars with petrol engines, and the supply solenoid in cars with diesel engines. The switch is positioned under the cover of the front right-hand door pillar, while the plastic fuel tank, which already meets future legislation, is located where it is protected in the event of a collision, and is able to resist any deformation without the risk of fuel leaks.

Active safety
The Grande Punto adopts the most sophisticated electronic systems to control the car's dynamic behaviour, implemented to take dynamic limits even higher so that they are not intrusive for the driver, while enhancing safety. The intervention of these devices has been studied with simulation and careful circuit tests in order to achieve an extremely enjoyable drive. A description of the generous equipment follows.

ABS with EBD (Electronic Brake force Distribution)
The Grande Punto's excellent braking system is supplemented by one of the most advanced ABS anti-lock braking systems around. It has four active sensors and a hydraulic control unit with 12 solenoids. The ABS system incorporates the EBD electronic brake effort distribution system. This distributes the braking effort to the four wheels to prevent them from locking, guaranteeing full control of the car in all conditions. The system also adapts to the grip conditions of the wheels and the efficiency of the brake pads, preventing them from overheating.

ESP (Electronic Stability Program)
The sophisticated ESP device cuts in when conditions are close to the limit, if the car's stability is at risk, to help the driver control the car. To do so, ESP constantly verifies the longitudinal and lateral grip of the tyres on the ground, and intervenes in the event of a skid to recover direction and stability. Sensors detect the rotation of the car around its vertical axis (yaw speed), lateral acceleration and the steering wheel angle set by the driver (which indicates his chosen direction). It compares these data with the parameters processed by a computer and uses a complex mathematical model to establish whether the car is taking a corner within the grip limits, or if it is about to skid at the front or the rear (understeer or oversteer). To recover the correct trajectory, the system generates a yaw contrary to the one that is causing the instability, braking the relevant wheel (inside or outside) individually and reducing the engine power (by adjusting the throttle valve). This is the peculiar feature of the device developed for the Grande Punto. The brake adjustments are modulated so that they are as smooth as possible (and will not disturb the driver) and the reduction in engine power is also limited, to guarantee excellent performance at all times and superbly enjoyable driving. ESP is always engaged.

Hill Holder - HBA
The Hill Holder is an integral part of the ESP device, assisting the driver on hill starts. It intervenes when the ESP control unit detects a change in the car's inclination through the longitudinal acceleration sensor on the floor under the passenger seat. During a hill start, the control unit prepares to intervene when first gear is engaged and the clutch and brake pedals are depressed. The pressure on the front callipers is maintained for about 1.5 seconds after the brake pedal is released, allowing the driver to set off more easily. On downhill starts with first gear engaged, the Hill Holder is not activated. The same is true for hill starts in which reverse is engaged: downhill the system is activated, whereas uphill it is not activated.

The HBA system is also available, an electro-hydraulic braking assistant which automatically increases the pressure in the braking circuit during emergency braking.

ASR (Anti Slip Regulation)
ASR (Anti Slip Regulation) is also built into the ESP system, optimising traction at all speeds, assisted by the brakes and the engine control.
The device monitors the wheel speed calculated by the ABS sensors to establish the amount of slip and triggers two different control systems to recover grip. When an excessive demand for power causes both drive wheels to slip (for example, aquaplaning or accelerating on an uneven, snow-covered or icy road surface), the system reduces engine torque by decreasing the throttle valve aperture and thus the air flow. If, on the other hand, only one wheel slips (for example the wheel on the inside of the bend, after acceleration or a dynamic change in the load), this wheel is automatically braked without the driver having to touch the brake pedal. The effect is similar to that of a self-locking differential. This gets the Grande Punto out of any difficulties on surfaces where grip is poor.

ASR is engaged automatically every time the engine is started, but can be excluded by a pushbutton on the central console. ASR must be excluded when snow chains are fitted because in this case, in order to transmit torque to the ground, the wheel needs to be able to 'accumulate' the snow, with small slips that the ASR tends to avoid.

MSR (Motor Schleppmoment Regelung)
This system is also an integral part of ASR, which acts during sudden gear changes when changing down, returning torque to the engine, and preventing excessive traction on the drive wheels which can cause the car to lose stability, particularly when grip is poor.

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