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Français
TORGA
PROJECT
TOWARDS SAFER MOBILITY FOR
TWO AND THREE-WHEELERS
Whether
it is simply to get around or to travel along country roads, riding a two or
three- wheeler is always synonymous with driving pleasure.. Thanks to their
compact size, motorcycles and scooters are also an excellent solution to
urban traffic and parking problems. On the other hand, security has always
been their weak point. All too often, the slightest fall or collision with
another vehicle still has tragic consequences.
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The Torga research
project aims to improve the safety
of motorcyclists, two or
three-wheels scooters riders and mopeds users through a new approach in
this field: programmed restraint.
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280,000 deaths per year is the sad toll
of road safety for motorized two-wheelers worldwide in 2018, according to WHO*.
The risk of death in an accident is on average 20 times higher for a user
of this type of vehicle than for a motorist.
In 2021, in France alone, there were nearly 600 deaths among
motorcyclists, 96 among moped riders and thousands of injuries **. Motorized
two-wheelers account for 21% of road deaths, while motorcyclists account
for only 1.5% of traffic.
However, although they represent only a small part of the vehicle
fleet in France, this is not the case everywhere. In Colombia, for example,
they represent 45% of all motor vehicles in circulation, 60% in China and
80% in India. In these countries where road deaths are on the rise,
two-wheeler users are paying a heavy price: 3,500 deaths in Colombia, about
70,000 in China and India. Not to mention the often seriously injured, for
whom it is difficult to obtain precise data, but who probably represent 10
times these figures. Road safety is a real public health problem at the
global level.
*Source : https://www.who.int/violence_injury_prevention/road_safety_status/2018/en/)
**Source:http://www.securite-routiere.gouv.fr/la-securite-routiere/l-observatoire-national-interministeriel-de-la-securite-routiere/accidentalite-routiere
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The weak points of
two-wheelers:
For primary safety :
- Difficulty braking the vehicle in an emergency, even with ABS;
- Sensitivity on low grip roads;
- Difficulty in rapidly changing path in an emergency situation.
For secondary safety :
- Low level of users's equipment: gloves, boots, jacket with or
without airbag, and sometimes still helmet;
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Exceptional presence of
airbags on the vehicle.
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One thing is certain:
the primary (active) and secondary (passive) safety systems of the
motorized two wheelers have not reached the level of maturity of those of
the automobile. In order to maintain the advantages inherent in two and
three-wheel motorcycles while reducing the risks associated with their use,
as well as the physical damage resulting from an impact or a fall, the
Torga research project is experimenting with different ways of improving
safety to complete the range of devices currently available: driver and
passenger equipment, airbag on vehicle or integrated in the jacket. It also
aims to improve comfort, in order to achieve a sustainable mobility and
pleasure formula for two and three-wheelers.
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In a
frontal impact, i.e. in 80% of accidents, the ejection speed of the driver
of a two-wheeled vehicle is the same as the initial speed of his vehicle.
Torga proposes to partially couple driver and passenger to the vehicle, in
order to dissipate part of the kinetic energy and reduce the violence of
the impact suffered by the driver. Explanations :
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Current situation: without coupling to the chassis
In a frontal impact between a two-wheeler and an
automobile at 50 km/h, the driver of the two-wheeler is ejected at 50 km/h
while his vehicle undergoes a very high deceleration, resulting in most
cases in the ejection of the pilot over a distance of 10 to 15 metres, with
fractures and burns, or other significant injuries, the most serious of
which affect the vertebrae, ribs and pelvis if he meets an obstacle on his
road.
Video on the right
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Option 1: coupling to the chassis
By coupling the driver to his vehicle, for example
by a seat belt, the latter benefits from the energy absorption provided by
the deformation of the front part of the chassis. His speed is therefore
significantly reduced when the rear wheel takes off from the ground.
Calculations show that, at that precise moment, it is 30 km/h for a
small scooter and less than 10 km/h for a heavy motorcycle (excluding
bio-mechanical constraints). This means a reduction of 20 and more than 40
km/h respectively compared to the initial speed of 50 km/h. The interest of
coupling was demonstrated by Raphael Murri of the Dynamic Test Center in
Vauffelin, Switzerland.
(http://www.dtc-ag.ch/downloads/publicat/sicherheitsgurt_motorrad_ifz08.pdf)
Limit of the
solution: risk of the driver being crushed by his vehicle if the rear wheel
takes off too abruptly, as illustrated on the figure and in the video opposite.
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Option 2: the programmed restraint proposed by Torga
To avoid any risk of the driver being crushed by
his own vehicle, he must be disconnected from it at some point. That's why
Torga offers a programmed restraint system that can disconnect the seat
belt, or any other coupling device used, when necessary.
This is particularly the case when the impact is
severe enough for the rear wheel to lift off the ground. The driver is then
ejected at reduced speed, after having benefited from the energy absorption
resulting from the deformation of the front part of the vehicle, thus
mitigating the consequences of the fall.
In a dual situation, the passenger, held
by the driver's back, benefits from energy dissipation and is also ejected
at reduced speed.
Video on the right
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The coupling means proposed here according to our
programmed restraint concept takes the form of a tank luggage holder. It is connected to the chassis by a
safety belt at the rear and a joint at the front, thus ensuring partial
coupling of the driver to the vehicle in the event of a frontal impact.
Compared to a conventional seat belt, this device is more user-friendly and
does not require any manipulation by the driver while sitting on the
vehicle.
During the first
phase of the impact, the driver's chest is projected forward and quickly
comes into contact with the reception area, in blue on the picture
opposite. The front part of the vehicle deforms and absorbs part of the
kinetic energy, which varies according to the initial speed and strength of
the chassis. This absorption results in a reduction in the speed of the
driver and passenger.
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If the impact is weak enough that the rear of the vehicle does not
lift, the driver's coupling is maintained and therefore the driver is not
released.
Otherwise, decoupling is necessary to avoid the risk of the rider
being crushed by his motorcycle. The luggage holder is uncoupled from the
side of its rear attachment to the frame by releasing the safety belt.
Under the effect of inertial forces, the support rotates around the articulation
axis located at its front part, thus releasing the driver, who is then
"ejected", with a much lower speed than would have been his
without this device.
The uncoupling of the support is ensured by a disconnectable fixing
managed electronically, acting on the belt buckle. The technologies used
are similar to those used to activate airbag vests.
Manual
action on the belt peduncle located in the front part of the saddle allows
the assembly to tilt forward to give access to the fuel hatch.
For
obvious reasons, the driver is not coupled to the vehicle in other crash
configurations or in the event of a fall.
The coupling means can take other forms, depending on the type of
vehicle targeted.
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As mentioned above, the moment when the rear wheel
lifts off during the collision depends on several factors, including the
vehicle's wheelbase and the position of its center of gravity. A long
vehicle with a low center of gravity close to the rear axle (e.g. a GT
motorcycle with a passenger) is better positioned for this issue than a
short vehicle with a high center of gravity close to the front axle (e.g. a
small scooter).
The graph opposite shows, on the ordinate, the
ejection speeds of the driver (in km/h) as a function of the speed of his
vehicle at the time of the impact, and the type of two-wheeler used.
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Improving motorcyclists' safety is an objective
of the Torga project. Reducing the number of accidents involving scooter
and other moped users is another, much more important given the tens of
millions of such vehicles on the planet's roads.
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The Torga
project proposes to provide technical answers to this problem while
improving comfort. After an initial modeling phase to explore the
ergonomics of the proposed solutions, scientific work will have to confirm
their potential to reduce the consequences of accidents before proceeding
to validation.
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