Technical Field
[0001] The present invention concerns a sports helmet, in particular a helmet providing
feedback to a wearer for improved aerodynamics.
Background for the Invention
[0002] Time trial cycling is a very specific cycling discipline wherein aerodynamics is
a very important key to success and wherein aerodynamics is highly dependent on the
position and posture of a rider on his bike. Time trial helmets are designed specifically
for minimizing drag of the rider during cycling and have proven their efficiency,
such a helmet is known from
DE 10 2012 214 061 A1.
[0003] However, the position of the time trial helmet in view of the riding direction is
critical for minimizing drag, as a non-optimal position of the helmet will have a
negative impact on the drag of the rider.
[0004] Cyclists specializing in time trial cycling spent a lot of time and effort in improving
their position including their head position when on the bike to identify the best
position and to develop themselves to adopt and maintain that optimal position when
riding.
[0005] Exercising is often performed by trial and error methods such as training in a velodrome,
recording the ride and subsequently analysing the recorded images with specific image
analysis software to compute the optimal position that is communicated to the rider
who can adjust his position in a subsequent ride or during training on rolls. Other
methods include driving down a hill and adjusting the head position to find the position
resulting in the fastest down hill times, whereby the head position is filmed or registered
by sensors provided on the cyclist's head. By repeating this exercise over and over
again, the cyclist literally customises himself to adopt the most efficient head position.
Other methods included training in wind tunnels and measuring the drag by means of
sensors provided on the helmet or by means of camera's allowing determining the air
movement around the cyclist's head.
[0006] Such exercises are very time consuming, have a slow learning curve and are expensive
due to the need of people surveying the cyclist during the exercise to conduct the
measurement and interpret the results. On top of the above facts it is necessary to
repeat the exercise when changing bike or helmet to customise the cycler to a readjusted
position.
[0007] From the above it is clear that there is a need for time trial helmets providing
instant feedback to a cyclist for adjusting his heads position for improved aerodynamics.
[0008] US5158089 discloses a headband comprising a sensor for determining and instant informing a
wearer of his head's position in view of the saggital plane, to improve his posture
and wellbeing.
[0009] US200401 71969 discloses a helmet comprising motion and/or position sensors and an indicator to
provide the wearer with a recognizable feedback signal indicative of head or motion
position.
Summary of the Invention
[0010] The present invention is defined in the independent claims. Preferred embodiments
are defined in the dependent claims. In particular the invention concerns a 1. A system
for optimizing a rider's head position during riding, said system comprising: a helmet
comprising:
- an outer casing designed to have a predetermined direction XREF wherein said helmet has a drag (coefficient) lower than the drag (coefficient) of
said helmet in any other direction;
- a sensor unit integrated in the helmet enabling determining a value corresponding
to the angle α between a measured direction X1 and the predetermined direction XREF defined in the plane defined by the field of gravity and the direction X1;
an output unit, providing an output signal to the helmet wearer in function of the
value determined by the sensor unit allowing the rider to immediately adapt the head
position to regain the optimum position with lowest drag, in which X1 corresponds to XREF and hence the angle α equals 0°.
[0011] The helmet preferably is a cycling helmet; skiing helmet or snow-board helmet, or
equestrian or motorcycle helmet and in particular a time trial cycling helmet, road
cycling helmet or triathlon helmet
[0012] The system further preferably comprises a sensor determining the inclination of the
surface whereon the rider rides in the direction of the movement. In a even more preferred
embodiment the system comprises at least three sensors, one integrated in the helmet,
on to be provided on the rider, separate from the helmet and one to be provided on
the vehicle of the rider, allowing determining the relative position of the rider
and it's helmet in view of the vehicle.
[0013] Potentially the system further comprises at least one sensor allowing determining
the wind direction in view of the helmets position and potentially also the forward
speed of the rider.
[0014] The helmet may comprise a signal emitter for emitting an output signal to the output
unit providing visual, audio and/or tactile feedback.
[0015] According to an alternative embodiment the system comprises a weight movably mounted
in a tail of the helmet and an actuation and guiding means allowing moving the weight
in said tail in view of the output of the sensor unit.
Brief Description of the Figures
[0016] Figure 1 schematically illustrates a time trial helmet with a system according to
the present invention.
Definitions
[0017] Drag coefficient: The drag coefficient
cd is defined as:

where:
Fd is the drag force, which is by definition the force component in the direction of
the flow velocity,
ρ is the mass density of the fluid,
v is the speed of the object relative to the fluid and
A is the reference area.
Detailed Description of a Preferred Embodiment
[0018] Figure 1 schematically represents a time trial cycling helmet 1 for safeguarding
a rider's head from head injury, yet comprising a outer casing designed such as lower
the drag of the rider during racing.
[0019] It is known to design such helmet 1 with an outer casing 2 to have a preferential
orientation during racing, in which position the casing design has a minimal drag
coefficient and improves (lowers) drag of the rider during the race. For optimal effect,
the rider should maintain his head in a position corresponding to the best position
of the helmet for maximal gain.
[0020] The optimum orientation of the helmet in view of the moving direction thereof is
defined by a direction X
REF, wherein said helmet has a drag (coefficient) lower than the drag (coefficient) of
said helmet in any other direction.
[0021] In order to continuously assist the rider in maintaining his head in a optimal (lowest
drag) position, the present invention concerns a system comprising at least one sensor
unit 3 integrated in or provided on the helmet. The sensor unit, in its most basic
form concerns an inclination sensor (mechanical or electronic) allowing determining
a value corresponding to the angle α between the X
1 direction and a predetermined direction X
REF defined in the plane defined by the field of gravity and the direction X
1. It is clear that for optimum drag conditions, the helmet should be worn according
to the helmet's safety guidelines. The X
REF direction in that case points towards the horizon in front of the rider when the
helmet is worn according these safety guidelines that are described in eg EN1078:2012,
CPSC 1203 or AS-NZS 2063.
[0022] In accordance with the present invention the system also comprises an output unit
4 allowing providing an output signal based on the value determined by use of the
sensor, the output unit can be integrated in the helmet or can be separate therefrom
and provides direct feedback to the rider allowing the rider to immediately adapt
his heads position in view of the output signal to regain his optimum position with
lowest drag on the bike, in which position X
1 corresponds to X
REF and hence the angle α equals 0°.
[0023] The output signal can be visualised to the rider, eg. on his eyewear or can be provided
as an audio signal or a vibration on the rider's skin.
[0024] As represented in figure 3, the sensor 3 unit comprises a housing 5 defining an internal
cavity wherein a ball 6 is provided that is free to roll in the cavity. The cavity
is delimited by a curved wall section 7 whereon the ball rolls when the helmet is
worn according to the safety guidelines in normal conditions (rider sitting on his
bike).
[0025] At at least one, but preferably two sides of the internal cavity, in the X
1 direction, sensors 8 are provided that generate an output signal on contacting the
ball. As such when the helmet tilts in view of the field of gravity in the X
1 direction and the angle α between X
1 and X
REF increases, the ball rolls in that direction and will contact one of the two sensors
8 thereby actuating one of the sensors to generate a signal that is translated in
a real-time output to the rider.
[0026] It is clear that the slope of the curved wall section 7 and position of the sensors
8 in the cavity of the sensor unit 3 will determine the threshold value of the angle
α over which X
1 may tilt in view of X
REF before a signal is generated.
[0027] According to other embodiments the sensor unit comprises a gyroscope or an accelerometer
allowing measuring tilting of the helmet in a plane defined by the direction X
1 and the field of gravity as this is the most difficult angle for a rider to maintain
during a race, ie. the inclination of the head in an upward and downward direction.
Alternatively the sensor unit comprises IR distance sensors or sound sensors directed
to the back of the rider when the helmet is worn according to its safety instructions.
Such sensors allow computing the distance and position of the helmet relative to the
rider's body, and as such determining or estimating a value corresponding to the angle
α between the direction X
1 and a predetermined direction X
REF.
[0028] In accordance with another embodiment and as represented in figure 2, the system
comprises at least two sensor units 3, 3', the first sensor unit 3 integrated in the
helmet and a second sensor unit 3' to be provided on the rider, preferably on his
back in close vicinity of the tail of the time trial helmet.
[0029] In this case both sensors units can be distance measuring units determining the distance
between both sensor units, whereby the measured distance corresponds to a value indicating
the direction X
1 and a pre-set distance corresponds to the value X
REF. An output unit generating an output signal as part of the system will provide real-time
feedback to the rider allowing maintaining or regaining his optimal lowest drag position
during racing.
[0030] In yet another alternative embodiment the system comprises at least one sensor unit
(an inclination sensor) integrated in or provided on the helmet and two sensor units
separate from the helmet, one to be provided in a predetermined position on the riders
body and one to be provided on a predetermined position on the bike, whereby the two
separate sensor units allow indicating the position of the rider on his bike together
with his head position. Such embodiment provides more information on the overall position
of the rider and allows more detailed and extensive feedback for optimizing the rider's
position during a race through the output unit.
[0031] In addition to the different embodiments of the system described above, additional
sensor units can be provided on the helmet allowing real-time determining the wind
direction and force acting on the helmet during a race and potentially also the forward
speed of the rider (independent of the wind speed). The output from these additional
sensor units can be processed and compared to test data generated with the helmet
to determine the optimum X
REF corresponding to the optimum orientation of the helmet under the given circumstances.
The measured X
1 value is in that case compared to a variable X
REF that is most representative for the actual racing conditions and allows for a more
precise feedback to the racer.
[0032] Another additional sensor unit that can be integrated in the system is an inclination
sensor provided on the bike or a GPS receiver, allowing determining the inclination
of the path whereon the rider rides. The values determined by such sensor units again
allows for a more accurate determination of the X
REF of the helmet in view of the racing conditions.
[0033] In the above described embodiments, the output unit can, apart from the real-time
feedback as a visual, audio or vibration signal comprise an additional aid to the
rider in terms of a mechanism changing the centre of mass of the helmet. Such output
unit comprises an element of weight that is movably along the direction X1, integrated
in the tail of the time trial helmet. The actuation of the movement is preferably
a motor that is controlled by the sensor units (including a processor) of the system
according to the present invention. By changing the centre of mass of the helmet,
one can increase the comfort of the rider while maintaining his head in an optimum
low drag position during racing.
[0034] The use of a system according to the present invention comprises determining the
X
REF of the helmet for a given rider. Such determination will usually be done in a wind
tunnel or by extensive on road testing. Once the X
REF is determined it is stored in the system for comparison with real time measurements
of the X
1 direction.
[0035] In case the system comprises a multitude of sensor units allowing determining racing
conditions, X
REF for a specific rider with his helmet is ideally determined under a broad variety
of conditions, such that for each of these conditions the optimum X
REF is available to the system and can be compared to the real time measured X
1.
[0036] Although described above as a system for optimizing a rider's head position during
riding with a time trial helmet, it is clear that the system according to the present
invention can be used with a multitude of helmets, such as other types cycling helmets,
including triathlon, skiing helmets or snow-boarding helmets.
1. A system for optimizing a rider's head position during riding, said system comprising:
a helmet comprising:
- an outer casing designed to have a predetermined direction XREF wherein said helmet has a drag (coefficient) lower than the drag (coefficient) of
said helmet in any other direction;
- a sensor unit integrated in the helmet enabling determining a value corresponding
to the angle α between a measured direction X1 and the predetermined direction XREF defined in the plane defined by the field of gravity and the direction X1;
- an output unit, providing an output signal to the helmet wearer in function of the
value determined by the sensor unit allowing the rider to immediately adapt the head
position to regain the optimum position with lowest drag, in which X1 corresponds to XREF and hence the angle α equals 0°.
2. The system according to claim 1, wherein said helmet is a sports helmet.
3. The system according to claim 1 and 2, wherein said helmet is a cycling helmet; skiing
helmet or snow-board helmet, or equestrian or motorcycle helmet..
4. The system according to claim 1, wherein said helmet is a time trial cycling helmet,
triathlon helmet or road cycling helmet.
5. The system according to claim 1, comprising a sensor determining the inclination of
the surface whereon the rider rides in the direction of the movement.
6. The system according to claim 1, comprising at least three sensors, one integrated
in the helmet, on to be provided on the rider, separate from the helmet and one to
be provided on the vehicle of the rider, allowing determining the relative position
of the rider and it's helmet in view of the vehicle.
7. The system according to claim 1, comprising at least one sensor allowing determining
the wind direction in view of the helmets position.
8. The system according to claim 1, the helmet comprising a signal emitter for emitting
an output signal to the output unit.
9. The system according to claim 3, comprising an element of weight movably mounted in
a tail of the helmet and an actuation and guiding means allowing moving the weight
in said tail in view of the output of the sensor unit.
10. The use of a helmet comprising an outer casing, a sensor unit and output unit for
providing an output signal to the helmet wearer in function of a value determined
by the sensor unit; and wherein the value corresponds to the angle between a measured
direction X1 and a predetermined direction XREF defined in the plane defined by the field of gravity and the direction X1; and wherein the predetermined direction XREF corresponds to a position of the helmet with the lowest drag.
1. System zur Optimierung der Kopfstellung eines Fahrers während dem Fahren, wobei das
System folgendes umfasst:
einen Helm, umfassend:
- eine äußere Schale, die so gestaltet ist, dass sie eine vorbestimmte Richtung XREF aufweist, wobei der Helm einen Strömungswiderstand (Strömungswiderstandskoeffizienten)
aufweist, der niedriger ist als der Strömungswiderstand (Strömungswiderstandskoeffizient)
des Helms in jede andere Richtung;
- eine Sensoreinheit, die in den Helm integriert ist, wobei sie die Bestimmung eines
Werts ermöglicht, der dem Winkel α zwischen einer gemessenen Richtung X1 und der vorbestimmten Richtung XREF entspricht, definiert in der Ebene, die durch das Gravitationsfeld und die Richtung
X1 definiert ist;
- eine Ausgangseinheit, die ein Ausgangssignal an den Träger des Helms als Funktion
des durch die Sensoreinheit bestimmten Werts bereitstellt, das es dem Fahrer ermöglicht,
die Kopfstellung sofort anzupassen, um die optimale Stellung mit dem geringsten Strömungswiderstand
wieder einzunehmen, wobei X1 XREF entspricht und somit der Winkel α gleich 0° ist.
2. System nach Anspruch 1, wobei der Helm ein Sporthelm ist.
3. System nach Anspruch 1 und 2, wobei der Helm ein Fahrradhelm, ein Skihelm oder ein
Snowboardhelm oder ein Reithelm oder ein Motorradhelm ist.
4. System nach Anspruch 1, wobei der Helm ein Zeitfahr-Fahrradhelm, ein Triathlonhelm
oder ein Straßenrad-Fahrradhelm ist.
5. System nach Anspruch 1, umfassend einen Sensor, der die Neigung der Oberfläche bestimmt,
auf welcher der Fahrer in Bewegungsrichtung fährt.
6. System nach Anspruch 1, umfassend wenigstens drei Sensoren, von denen einer in dem
Helm integriert ist, einer zur Bereitstellung an dem Fahrer vorgesehen ist, getrennt
von dem Helm, und einer zur Bereitstellung an dem Fahrzeug vorgesehen ist, wobei die
Bestimmung der relativen Position des Fahrers und dessen Helms in Bezug auf das Fahrzeug
ermöglicht wird.
7. System nach Anspruch 1, umfassend wenigstens einen Sensor, der die Bestimmung der
Windrichtung in Bezug auf die Helmstellung ermöglicht.
8. System nach Anspruch 1, wobei der Helm einen Signalgeber zur Abgabe eines Ausgangssignal
an die Ausgangseinheit umfasst.
9. System nach Anspruch 3, umfassend ein Gewichtselement, das beweglich in einem hinteren
Bereich des Helms angebracht ist, und eine Betätigungs- und Führungseinrichtung, die
eine Bewegung des Gewichts in dem hinteren Bereich in Bezug auf die Ausgabe der Sensoreinheit
ermöglicht.
10. Verwendung eines Helms, der eine äußere Schale, eine Sensoreinheit und eine Ausgangseinheit
zur Bereitstellung eines Ausgangssignals an den Helmträger als Funktion eines durch
die Sensoreinheit bestimmten Werts umfasst; und wobei der Wert dem Winkel zwischen
einer gemessenen Richtung X1 und einer vorbestimmten Richtung XREF entspricht, definiert in der Ebene, die durch das Gravitationsfeld und die Richtung
X1 definiert ist; und wobei die vorbestimmte Richtung XREF einer Stellung des Helms mit dem geringsten Strömungswiderstand entspricht.
1. Système permettant d'optimiser la position de la tête d'un utilisateur pendant l'utilisation,
ledit système comprenant :
un casque comprenant :
une enveloppe externe conçue pour avoir une direction prédéfinie XREF, ledit casque ayant une traînée (coefficient de traînée) inférieure à la traînée
(coefficient de traînée) dudit casque dans toute autre direction ;
une unité de capteur intégrée dans le casque permettant de déterminer une valeur correspondant
à l'angle α entre une direction mesurée X1 et la direction prédéfinie XREF définie dans le plan défini par le champ de gravité et la direction X1 ;
une unité de sortie, fournissant un signal de sortie au porteur du casque en fonction
de la valeur déterminée par l'unité de capteur permettant à l'utilisateur d'adapter
immédiatement la position de la tête pour retrouver la position optimale avec la plus
faible traînée, X1 correspondant à XREF et ainsi l'angle α étant égal à 0°.
2. Système selon la revendication 1, ledit casque étant un casque de sport.
3. Système selon les revendications 1 et 2, ledit casque étant un casque de vélo, un
casque de ski ou un casque de snow-board ou un casque d'équitation ou de moto.
4. Système selon la revendication 1, ledit casque étant un casque de cyclisme contre
la montre, un casque de triathlon ou un casque de cyclisme sur route.
5. Système selon la revendication 1, comprenant un capteur déterminant l'inclinaison
de la surface que l'utilisateur parcourt dans la direction du mouvement.
6. Système selon la revendication 1, comprenant au moins trois capteurs, un capteur intégré
dans le casque, un capteur à placer sur l'utilisateur, séparé du casque et un autre
capteur à placer sur le véhicule de l'utilisateur, ce qui permet de déterminer la
position relative de l'utilisateur et de son casque par rapport au véhicule.
7. Système selon la revendication 1, comprenant au moins un capteur permettant de déterminer
la direction du vent en fonction de la position du casque.
8. Système selon la revendication 1, le casque comprenant un émetteur de signaux destiné
à transmettre un signal de sortie à l'unité de sortie.
9. Système selon la revendication 3, comprenant un élément de poids monté mobile dans
une queue du casque et un moyen d'actionnement et de guidage permettant de déplacer
le poids dans ladite queue en fonction de la sortie de l'unité de capteur.
10. Utilisation d'un casque comprenant une enveloppe externe, une unité de capteur et
une unité de sortie pour transmettre un signal de sortie au porteur du casque en fonction
d'une valeur déterminée par l'unité de capteur ; et la valeur correspondant à l'angle
entre une direction mesurée X1 et une direction prédéfinie XREF définie dans le plan défini par le champ de gravité et la direction X1 ; et la direction prédéfinie XREF correspondant à une position du casque ayant la plus faible traînée.