Patent Description:
Airbags for the protection of a person's head are known in the art, for example through <CIT>. <CIT> and <CIT> describe protective systems according to the preamble of claim <NUM>. As opposed to vehicular airbags the airbag of <CIT> is designed to inflate into a complex head protecting shape. The airbag is designed as a double-bag construction, of which the inflated helmet-shape of the inner plastic bag is formed by the finger like construction of the outer bag.

The airbag mentioned in <CIT> is designed to detect if the user is exposed to an abnormal movement, such as a fall or a collision, for a specific activity, for example riding a bicycle. For the airbag to protect the user during an accident, the user has to wear the airbag when doing the specific activity. During the activity the wearable airbag is activated, constantly monitoring the movements of the user. As inflation is controlled by comparing the current movement with reference movements of the particular type of activity, it is important to turn off the wearable airbag once the type of activity is changed, e.g. from cycling to walking or running. Compared to traditional helmets the wearable airbag is so gently arranged around the neck that a user may easily forget that he or she is actually wearing it. Hence, deactivation of the wearable airbag may be forgotten. There is thus a need for an airbag that eliminates or at least mitigates problems arising from this situation.

The airbag mentioned in <CIT> is designed in such a way that an evaluation and control unit receives presence signals from at least one external safety component and/or at least one internal safety component and evaluates the received signals in order to detect the safety components currently available.

The airbag mentioned in <CIT> is designed in such a way that the airbag is started before the user falls down using a self-test procedure.

An object of the present invention is to provide a new type of airbag system which is improved over prior art and which eliminates or at least mitigates the drawbacks discussed above. More specifically, an object of the invention is to provide an airbag system that is configured to communicate with an external device.

According to the invention, a protective system as described in claim <NUM> is provided. The protective system comprises an airbag system in the form of an inflatable helmet for protecting a body part of a user in case of an accident, comprising a control unit and a communication interface. The system further comprises an external device comprising communication means, wherein the communication interface of the airbag system is configured to communicate with said external device using wireless communication.

In one embodiment, the wireless communication is short-range wireless communication. The short-range wireless communication may pertain to any of Bluetooth, WLAN, WiFi, NFC, RF-ID or IrDA. This allows for efficient and cheap communication.

According to the invention, the communication interface of the airbag system is configured to attempt to communicate with said external device. If the communication between the airbag system and the external device is successful, the control unit of the airbag system is configured to control the airbag system into a first mode. In the first mode the control unit is configured to automatically put the airbag system into an active state and/or to alert the user to manually change to an active state. The communication between the airbag system and the external device will only be successful if they are close to each other, i.e. within the range of the wireless communication. In this way the system can determine if the airbag system is close to the external device.

In one embodiment the communication between the airbag system and the external device is successful when a communication is established between the airbag system and the external device. In another embodiment the communication between the airbag system and the external device is successful when a communication is established between the airbag system and the external device and when the external device and the airbag system are within a predetermined distance from each other.

According to the invention, if the communication between the airbag system and the external device is not successful, the control unit of the airbag system is configured to automatically put the airbag system in an idle state and/or to alert the user to manually change to an idle state.

In one embodiment, if the communication between the airbag system and the external device is not successful a controller of the external device is configured to control the external device into a safety mode. If the communication between the airbag system and the external device is successful a controller of the external device may be configured to disable a safety mode of the external device. In the safety mode the controller of the external device may be configured to lock the external device so as to prevent the user from using it.

The external device may be an electric bicycle and wherein in the safety mode the controller of the electric bicycle may be configured to lock the electric bicycle so as to prevent the user from using it or to reduce the allowed speed of the electrical bicycle.

In one embodiment the external device is a bicycle.

In an alternative embodiment, the external device is a bicycle lock.

The present invention will hereinafter be further explained by means of nonlimiting examples with reference to the appended schematic figures where;.

The protective system enclosed herein comprises an airbag system <NUM> for protecting a body part in case of an abnormal movement of a user and at least one external device <NUM>. The external device <NUM> may for example be a bicycle or a bicycle lock.

The airbag system <NUM> is configured to be used to detect an accident, such as a fall or collision, for example when a user is riding a bicycle. The airbag system <NUM> may thus be configured for the specific use of riding a bicycle. For the airbag system to protect the user during an accident, the user has to wear the airbag system and have it turned on, or activated when performing the specific activity. It would however be preferred to provide a system that determines if the airbag system is needed and in response to that alert the user and/or change the mode of the airbag system and/or change the mode of the external device.

Furthermore, having the airbag system set in an activate state when the user is not doing the intended activity, e.g. not cycling, results in an undesirable energy loss since the airbag system is in an active state using battery power to power a sensor(s) and to process the movement data gathered therefrom, although there is no risk for a fall or collision.

It would thus be beneficial if the computational demanding determination, if a user is about to fall or collide when doing the indented activity, e.g., riding a bicycle, is deactivated when it's not needed so as to reduce the overall energy consumption of the system.

The system herein aims at determining if the airbag system is needed, in particular if a user is actually performing the intended activity or not. This information may for example be used to change the mode of the airbag system <NUM> and/or the mode of the external device.

The system herein aims at determining if the airbag system <NUM> is needed or not. This is done by differentiating between situations where the airbag system <NUM> is within a predetermined distance from the external device <NUM> and when they are far away from each other. This information may for example be used to change the mode of the airbag system <NUM> and/or the mode of the external device <NUM>.

Before turning to a detailed description of the disclosed embodiments, an exemplifying environment of the airbag system <NUM> device will be described with reference to <FIG>, and an exemplifying environment of the external device <NUM> will be briefly described with reference to <FIG>.

<FIG> shows an airbag system <NUM> according to an embodiment in its non-inflated state. The airbag system <NUM> comprises an apparel <NUM> having the shape of a collar which is worn around the neck <NUM> of a user <NUM>. An idea of the airbag system <NUM> is to provide a wearable airbag system for protecting a body part in case of an abnormal movement of a user, such as a fall or a collision. The airbag system described herein may for example be used instead of an ordinary rigid helmet, e.g. when bicycling. The airbag system is comfortable to wear, does not affect the user's hair style when worn and does not obstruct vision or hearing when worn in its non- inflated state.

The collar <NUM> is placed around the neck of the user and has for that purpose a sealable opening <NUM>, normally at the front of the collar. Alternatively, the opening <NUM> may be arranged at the back of the collar <NUM> or at the shoulder portion of the collar <NUM>. Furthermore, the opening <NUM> may be totally or partly divideable.

In one embodiment, the opening <NUM> is sealed using interlocking means (not shown) to connect the ends of the collar <NUM> e.g. adjacently the user's <NUM> throat or neck region. The interlocking means facilitates easy dressing and undressing of the collar <NUM> on the user <NUM>. Furthermore, the position of the different parts of the interlocking means determines if the airbag system <NUM> is turned on (i.e. having power) or turned off, and if its turned on in an active state or in an idle state.

In another embodiment the sealing may be arranged as a zipper, buttons, a Velcro fastening, magnets, hooks, hanks, buckles, safety pins, straps or the like. The collar <NUM> may be made of any kind of flexible material, such as acetate silk, jeans, fleece, cotton, beaver nylon or any other suitable fabric.

When the airbag system is not worn by the user, the collar <NUM> can be put in a resting position to allow the user to easier carry the collar <NUM> for example by putting it in a bag. All electronics in the airbag system is turned off when the airbag system is put in the resting position. In the resting position the collar is connected such that the diameter of the collar is greatly reduce. This prevents the user from being able to have to collar <NUM> arranged around the neck when the collar is in its resting position.

The collar <NUM> comprises a folded airbag <NUM> which is inflated to form a helmet for protecting the head of the user <NUM> in case of an abnormal movement, e.g. during a cycling accident.

An inflated helmet is schematically shown in <FIG>. Here, the collar <NUM> is opened to release the airbag <NUM> previously enclosed therein. The airbag <NUM> surrounds the neck <NUM> and the head <NUM> of the user <NUM> and provides an efficient protection for the user <NUM>.

The airbag <NUM> is formed by a flexible material in order to be folded and stored within the collar <NUM> prior to inflation. The airbag <NUM> may e.g. comprise an inflatable inner bag surrounded by an outer bag. Inflation of the inner bag leads to expansion of the outer bag and the structure of the outer bag defines the shape of the airbag when the inner bag is inflated. Although not shown in <FIG>, the airbag system may also be an one-bag construction.

The inner bag may be made of a fluid impermeable material, such as thermoplastic polyurethane film. Since fluid cannot easily leave a fluid impermeable bag, a person wearing an airbag <NUM> according to the invention will be protected by said airbag <NUM> for some time after expansion of the airbag <NUM>, effectively protecting the head of the user for the entire time of the accident. The inner bag may be flexible and expandable such that it may expand the outer bag upon inflation to a high pressure. Hence, the inner bag may be inflated resulting in a relatively high internal pressure which may be maintained for some time.

An example of how the inner and outer bag may be configured is described in <CIT> by the same applicant.

As shown in <FIG>, the airbag system <NUM> further comprises at least one sensor <NUM> for detecting movement of the collar <NUM>, i.e. movement of the user <NUM>, and a control unit <NUM> configured to in response to the information gained by the sensor <NUM> determine if the movement corresponds to an accident situation. If an accident situation is determined, the control unit <NUM> trigger inflation of the airbag <NUM> by means of an inflation device <NUM>. The airbag system <NUM> further comprises a power source <NUM>, for example a rechargeable battery or a disposable battery, in order to provide electrical power to the parts of the system <NUM>. The different parts will now be described more in detail.

The inflation device <NUM> may be any suitable type of airbag inflation device, such as a hybrid generator using a combination of compromised gas and solid fuel, a pyrotechnic airbag inflator which uses hot gases formed by powder, a heated gas inflator or a an inflation device using solid fuel. In an embodiment, the inflation device is a cold gas inflator.

The inflation device <NUM> is provided with a gas guide <NUM>, for directing the gas into the airbag. The inflation device <NUM> is clamped, screwed, glued, sewed or the like onto the textile bag and the gas guide <NUM> is positioned inside the textile bag for directing the gas into the bag for inflating the airbag in a proper manner. The gas guide <NUM> may be T-shaped for being able to lead the gas into the airbag in a suitable stable way. Alternatively the gas guide <NUM> may be Y- shaped, I-shaped, arrow-shaped, multiple-part shaped cylindrical shaped or the like.

The inflation of the airbag <NUM> is controlled by the control unit <NUM>. The control unit <NUM> controls the inflation of the airbag in case of an abnormal movement and prevents the airbag system from releasing at an undesired occasion. The control unit <NUM> may be implemented using instructions that enable hardware functionality, for example, by using executable computer program instructions in a general-purpose or special-purpose processor that may be stored on a computer readable storage medium (disk, memory etc.) <NUM> to be executed by such a processor. The control unit <NUM> may be configured to read instructions from the memory <NUM> and to execute these instructions to control the operation of the airbag system <NUM>. The control unit <NUM> may be implemented using any suitable, publically available processor or Programmable Logic Circuit (PLC). The memory <NUM> may be implemented using any commonly known technology for computer-readable memories such as ROM, RAM, SRAM, DRAM, FLASH, DDR, SDRAM or some other memory technology.

The control unit <NUM> may be a dedicated control unit <NUM> or the control unit <NUM> may also be configured to control other functions.

The at least one sensor <NUM> collects data relating to the movement of the collar <NUM>. The sensor <NUM> may be an accelerometer, a gyro, an air ultrasonic transducer, radar and/or a laser. In one embodiment at least one sensor is an accelerometer measuring acceleration in three dimensions and/or the sensor is a gyro detecting angular speed in three dimensions. Additionally, or alternatively, the at least one sensor <NUM> may be an ultrasonic transducer, or any device using electromagnetic waves, that measures the distance from the ground to the collar <NUM>.

<CIT>, filed by the same applicant, discloses a method for detecting a bicycle accident without falsely classifying any data samples from normal cycling activities as accident. The system classifies the detected movement into either a "normal class" relating to movement patterns representing riding a bicycle or doing related activities or into an "action class" relating to movement patterns representing a bicycle accident.

The movement data gathered from the at least one sensor <NUM> is transmitted to the control unit <NUM>. The control unit <NUM> processes the data and analyses it in order to evaluate if the processed data corresponds to an accident situation. If the data corresponds to pre-stored data indicating an accident situation, the control unit <NUM> transmits a triggering signal to the inflation device <NUM> to trigger the inflation of the airbag <NUM>. The airbag <NUM> will consequently be inflated when the inflation device <NUM> receives the triggering signal.

The controller is coupled to the memory <NUM>, which saves the measured and processed data. The saved data can be used to review and analyse the activity history of the airbag system. This is particularly useful if the airbag system has been deflated and technicians want to verify that the airbag system was working properly.

The airbag system <NUM> further comprises a communication interface <NUM>, which is adapted to allow the airbag system <NUM> to communicate with other devices through the use of different communication technologies. Such communication technologies may be wired or wireless. Examples of such wired technologies are Universal Serial Bus (USB) and Ethernet to name a few. Examples of such wireless technologies are IEEE <NUM>, IEEE <NUM>, ZigBee, WirelessHART, WIFI, Bluetooth®, W-CDMA/HSPA, GSM, UTRAN and LTE to name a few. It should be noted that other technologies exist and are taken to be an obvious equivalent for such wireless communication interfaces.

Preferably, the communication interface <NUM> uses short-range wireless communication such as any of Bluetooth®, WLAN/WiFi, NFC (Near Field Communication), RF-ID (Radio Frequency Identification) or IrDA (Infrared Data Association).

If the communication interface <NUM> uses Bluetooth, the communication interface <NUM> has the benefit that it also can measure the distance between the airbag system <NUM> and other devices. This distance can for example be used to determine if the airbag system is to be put in an active or idle state.

The airbag system <NUM> may further comprise a user interface <NUM>. The user interface <NUM> produces a signal detectable by the user, so as to alert the user <NUM> with different information. The user interface <NUM> may be used to alert the user <NUM> that his/hers external device <NUM> is nearby in order to remind the user to put the airbag system <NUM> in an active state and/or to alert that his/her external device <NUM> is far away and thus remind the user to turn off the airbag system <NUM>. The user interface <NUM> may also be configured to indicate the status of the airbag system <NUM>, i.e. the battery level, if the battery is in need for charging, if the inner elements of the helmet is intact or not, and if the system <NUM> is turned on. The user interface <NUM> may also indicate if the system <NUM> is turned on in an idle state or an active state.

The alert signal could be in the form of an audible signal such as siren, a haptic signal such as a vibration, a visual signal such as a strobe light or other sensory alarm that could be arranged on a user in the form of an airbag system <NUM>.

The user interface <NUM> may comprise one or a plurality of light emitting diodes (LED), which indicate information using light signal(s). Different colors of the light or flashing signals may for example indicate different information. The user interface <NUM> may also comprise a speaker <NUM> sending out a sound signal, such as a buzz, or a device sending out a vibrating signal or a spoken phrase.

In an embodiment where the user interface <NUM> comprises a speaker <NUM>, the speaker <NUM> may be used to send sound signals from an external device <NUM>, transmitted using the communication interface <NUM>. This external device <NUM> may be a different external device <NUM> than the one previously mentioned. These sound signals may e.g. comprise navigational signals directing the user where to turn, possibly using a global positioning system (GPS) <NUM> of an external device <NUM> (see <FIG>).

The airbag system <NUM> has to be turned on, i.e. having power, in order to work properly. In one embodiment the airbag system <NUM> is turned on using an on/off-button arranged somewhere on the collar <NUM>. In yet one embodiment, the airbag system <NUM> is turned on automatically once the collar <NUM> is placed around the neck <NUM> of the user <NUM>.

In some embodiments, the airbag system <NUM> may either be turned on in an activate state or in an idle state. In the active state all parts of the airbag system <NUM> are active and the airbag is thus allowed to be inflated by a triggering signal. In the idle state the airbag systems <NUM> is powered up but other functions may be idle. In idle mode, the control unit <NUM> may be active whereas the inflation device <NUM> and the sensor(s) <NUM> is inactivated (i.e. no triggering signal is detected and the airbag is not inflated).

In one embodiment, the idle state and the active state is turned on/off by the interlocking means arranged on the collar <NUM>. The interlocking means comprises a first fastening body and a second fastening body. One end of the first and second fastening body are each connected to the collar <NUM>. The collar <NUM> is thus easily attached to the neck of the user by attaching the first fastening body and the second fastening body to each other, and the collar <NUM> is released from the neck of the user <NUM> by detaching the first and second fastening bodies from each other. In a preferred embodiment, the first and second fastening body are a female and male connector.

The interlocking means is configured to be arranged in a first locking position or a second locking position when the first fastening body and the second fastening body are connected to each other. When the interlocking means is in a first locking position, the system <NUM> is put into an idle state and when the interlocking means is in a second locking position, the system <NUM> is put into an active state.

As already mentioned, the protective airbag system <NUM> further comprises an external device <NUM>, which will now be briefly described with reference to <FIG>.

In the embodiment shown in <FIG> and in the following description, the external device is shown in the form of a bicycle <NUM>. However, the external device mentioned herein is not limited to these examples but may take any possible form as long the device <NUM> comprises means for communicating within the airbag system <NUM>. If the indented use for the airbag system <NUM> is riding a bicycle, the external device <NUM> may for example be a bicycle lock or any other device suitable for attachment on or in conjunction of a bicycle. If the intended use of the airbag system <NUM> is horse riding, the external device <NUM> may be a device suitable to be arranged on the horse, for example a saddle or a bridle.

The bicycle may be of any type of bicycle having at least one wheel such as a bicycle with one wheel, i.e. a unicycle, an ordinary bicycle having two wheels, a tricycle having three wheels or a quadracycle having four wheels. The bicycle may for example be a utility bicycle, mountain bicycles racing bicycle, hybrid bicycle, BMX bike, a tandem or an electric bicycle.

In the embodiment shown in <FIG>, the bicycle <NUM> comprises two wheels, a frame, two pedals, a saddle and a front set having a handlebar grip. However, the external device <NUM> is not limited to any particular kind when it comes to physical design.

The external device <NUM> may also be a separate device which is configured to be attached to the bicycle.

The external device <NUM> further comprises means for communication. The external device <NUM> may comprise a communication interface <NUM> that communicates with the communication interface <NUM> arranged in the collar <NUM>. Preferably, the communication interface <NUM> uses short-range wireless data communication, such as short-range wireless data communication such as, for instance, Bluetooth®, WLAN/WiFi, NFC (Near Field Communication), RF-ID (Radio Frequency Identification) or IrDA (Infrared Data Association).

If the communication interface <NUM> uses Bluetooth, the communication interface <NUM> has the benefit that it also can measure the distance between external device <NUM> and other devices such as the airbag system <NUM>. This distance can for example be used to determine if a communication is successfully achieved.

In some embodiments, the external device <NUM> further comprises a controller <NUM>. The controller <NUM> may be responsible for general device operations of the external device <NUM>, for example controlling the speed and/or the ON-OFF function of the external device. This is particularly true in the embodiments where the external device <NUM> is an electrically powered bicycle.

The controller <NUM> may be implemented using any suitable, publically available processor or Programmable Logic Circuit (PLC). The controller <NUM> may be in operative connection with a memory (not shown). The memory may be implemented using any commonly known technology for computer-readable memories such as ROM, RAM, SRAM, DRAM, FLASH, DDR, SDRAM or some other memory technology.

In some embodiments, the external device <NUM> comprises a user interface <NUM>. The user interface <NUM> produces a signal detectable by the user, so as to alert the user <NUM> with different information. The user interface <NUM> may be used to alert the user <NUM> that his/her airbag system <NUM> is turned off or in an idle ON-state and thus remind the user <NUM> to turn on the airbag system <NUM>. The user interface <NUM> may also be configured to indicate the status of the external device <NUM> such as the battery level.

Preferably, the user interface <NUM> may comprise one or a plurality of light emitting diodes (LED), which indicate information using light signal(s). Different colors of the light may for example indicate different information.

The alert signal could also be in the form of an audible signal such as siren or a buzz or other sensory alarm that could be arranged on the external device <NUM>.

If the bicycle is an electric bicycle it may also comprises an integrated electric motor (not shown) which can be used for propulsion and a controller for controlling the applied speed. There are many possible types of electric motorized bicycles with several technologies available and these will thus not be described further.

In another embodiment, as is schematically illustrated in <FIG>, the external device <NUM> is a mobile phone <NUM>. The user interface <NUM> of the airbag system <NUM> comprises a speaker <NUM>, configured to transmit sound signals generated by the mobile phone <NUM>, and transmitted using the communication interface <NUM>. These sound signals may e.g. be streamed audio data, comprising real-time navigational signals directing the user where to turn, possibly using a global positioning system (GPS) <NUM> of the mobile phone <NUM>.

The provision of a protective system comprising an airbag system <NUM> and a external device <NUM> which differentiates between when the airbag system <NUM> and the external device <NUM> are within a predetermined distance or not solves or at least reduces the problem of having a person riding a bicycle without turning on the airbag system <NUM> and/or having a person walking around with the airbag system <NUM> in a powered state. This is done by the fact that the airbag system <NUM> and the external device <NUM> in the protective system interacts wirelessly with each other. If the airbag system <NUM> succeeds in establishing a short-range wireless data communication with the external device <NUM>, one can assume that the user <NUM> of the airbag system <NUM> is in the vicinity of the external device <NUM>. The communication may be used to change the mode of the airbag system <NUM> and/or the mode of the external device <NUM> depending on the communication status.

In the embodiment where the external device <NUM> is a bicycle or a bicycle lock the communication has several benefits, as will now be described.

The airbag system <NUM> is intended to be worn when riding a bicycle and is configured to determine if an accident, such as a fall or collision, has occurred when riding the bicycle. In order to reduce the power consumption and the possible risk of the airbag system <NUM> inflating unintentionally, the airbag system <NUM> should only be turned on, or turned on in an active state, when the user <NUM> is riding the bicycle or is in proximity of the bicycle (intending to ride the bike, or if he/she just got off the bike). If the airbag system <NUM> is turned on, or turned on in an active state, when the user <NUM> is moving away from his/hers bicycle <NUM>, it would be preferable if the system <NUM> would be turned off or turned into an idle ON-state.

Furthermore, if the airbag system <NUM> is not turned on, or turned on in an idle state, while the user <NUM> is in proximity of his/hers bicycle <NUM> it would be beneficial if the bicycle <NUM> was put in a safety mode where the speed of the bicycle is reduced or where its not possible to bike at all (due to power cut off in the case of an electric bicycle or by a locking device).

According to the invention, the communication interface <NUM> of the airbag system <NUM> is configured to attempt to communicate with the external device <NUM> using wireless communication. Additionally, or alternatively, the external device <NUM> is configured to attempt to communicate with the airbag system <NUM>.

This attempt is conducted at predetermined time intervals, for example every <NUM> seconds, every minute or every second minute. The attempt may also be more seldom, such as every fifth minute.

In some embodiments the communication attempt is only conducted when it is detected that the user <NUM> of the airbag system <NUM> is walking and/or not riding a bicycle. In some embodiments the airbag system <NUM> is configured to determine what activity state the user is in, e.g. if the user is walking or riding a bicycle, based on movement data gathered from at least one sensor, the sensor either being the same as the sensor colleting movement data for triggering of the inflation or an additional sensor. The communication attempt may then be conducted only when the airbag system <NUM> is in a walking activity state, or when the user is not in a bicycling activity state.

In one embodiment the communication between the airbag system <NUM> and the external device <NUM> is considered to be successful if a communication is established between the airbag system <NUM> and the external device <NUM>. In another embodiment the communication between the airbag system <NUM> and the external device <NUM> is successful if a communication is established between the airbag system <NUM> and the external device <NUM> and if the airbag system <NUM> and the external device <NUM> are within a predetermined distance from each other. The predetermined distance may be measured by the communication interface <NUM> of the airbag system and/or by the communication means <NUM> of the external device <NUM>.

The communication between the airbag system <NUM> and the external device <NUM> will now be described further with exemplified embodiments with reference to <FIG>.

As seen in the embodiment of <FIG>, if the communication between the airbag system <NUM> and the external device <NUM> is successful, the control unit <NUM> of the airbag system <NUM> is configured to put the airbag system <NUM> in a first mode. Depending on configuration the first mode may pertain to different functions.

In the first mode the control unit <NUM> may be configured to alert the user <NUM> that he/she should manually turn on, or turn on in an activate state, the airbag system <NUM> since he/she is in close proximity of the bicycle <NUM>. If the airbag system <NUM> already is turned on, or turned on in an activate state, the control device <NUM> may be configured to not alert the user. The alert to the user <NUM> may be generated by the user interface <NUM> which produces a signal detectable by the user as described with reference to <FIG>.

Additionally, or alternatively, the control unit <NUM> may be configured, in the first mode, to automatically put the airbag system <NUM> in an active state if the airbag system <NUM> has an idle ON-state and an active ON-state. In this way the airbag system <NUM> is always turned on and ready to protect the user <NUM> in case of a bicycle accident when the bicycle <NUM> is in proximity to the user <NUM>.

If instead the communication between the airbag system <NUM> and the external device <NUM> is not successful, i.e. either the communication establishment fails or the communication is established but the airbag system <NUM> and the external device <NUM> is not within the predetermined distance from each other, the control unit <NUM> of the airbag system <NUM> is configured to put the airbag system <NUM> in a second mode. Depending on configuration the second mode may pertain to different functions.

In the second mode the control unit <NUM> may be configured to alert the user <NUM> that he/she should manually turn off, or turn the airbag system in an idle state, since he/she is not in close proximity of the bicycle <NUM>. If the airbag system <NUM> already is turned on in an idle state, the control device <NUM> may be configured to not alert the user <NUM>.

Additionally, or alternatively, the control unit <NUM> may be configured, in the second mode, to automatically turn off the airbag system <NUM> or put the airbag system <NUM> in an idle state if the airbag system <NUM> has an idle ON-state and active ON-state. In this way the airbag system <NUM> is turned off, or turned into an idle ON-state, once the user <NUM> is not in proximity of the bicycle <NUM>. This reduces battery consumption of the airbag system <NUM> and eliminates the possible risk of the airbag <NUM> being inflated unintentional.

In the embodiment shown in <FIG>, the state of the external device <NUM> ischanged depending on the communication between the airbag system <NUM> and the external device <NUM>. As seen in the embodiment of <FIG>, if the communication between the airbag system <NUM> and the external device <NUM> is successful the controller of the external device <NUM> is configured to disable the external device <NUM> from a safety mode, if activated.

If instead the communication between the airbag system <NUM> and the external device <NUM> is not successful, i.e. fails, the controller of the external device <NUM> is configured to put the external device <NUM> in a safety mode of the external device <NUM>.

Depending on configuration the safety mode may pertain to different functions. In the safety mode the controller <NUM> of the external device may be configured to alert the user <NUM> to put on the airbag system <NUM> in an idle mode. This may for example be done by a light indicator visibly arranged on the external device <NUM>.

Additionally, or alternatively, the controller <NUM> of the external device <NUM> may be configured, in the safety mode, to prevent the user <NUM> from using the external device <NUM>. This may for example be prevented by locking the bicycle by a locking device (not shown) which is locked in a safety mode and unlocked when the safety mode is disabled. Such a locking device may be a smart lock which is able to communicate with the external device <NUM>, so as to open the lock when the safety mode is disabled.

In the embodiment where the external device <NUM> is a bicycle lock, the locking device is able to communicate with the airbag system <NUM> so that the safety mode of the external device <NUM> pertains to locking the bicycle lock. Disabling the safety mode thus means opening the bicycle lock.

In the embodiment where the external device <NUM> is an electric bicycle, the user could also be prevented from using the bicycle <NUM> by having a safety mode configured to lock the electric bicycle <NUM> so as to prevent the user <NUM> from using it by power cutoff. Alternatively, the safety mode is configured to reduce the maximum allowed speed of the electrical bicycle <NUM>. In this way, if the user <NUM> is not wearing the airbag system <NUM>, or the system is not turned on in an active state, the bicycle cannot be used or can only be used at a slow speed.

The two embodiments disclosed in <FIG> can be combined. One such combination is seen in <FIG>, showing that if the communication is successful the airbag system <NUM> is put in a first mode and the external device <NUM> disables the safety mode, if present. If the communication fails, the airbag system <NUM> is put in a second mode and the external device <NUM> is put in a safety mode.

Claim 1:
Protective system, comprising:
an airbag system (<NUM>) in the form of an inflatable helmet for protecting a body part of a user (<NUM>) in case of an accident, comprising a control unit (<NUM>) and a communication interface (<NUM>); and
an external device (<NUM>) comprising communication means (<NUM>),
wherein the communication interface (<NUM>) of the airbag system (<NUM>) is configured to communicate with said external device (<NUM>) using wireless communication,
wherein the communication interface (<NUM>) of the airbag system (<NUM>) is configured to attempt to communicate with said external device (<NUM>),
characterized in that
if the communication between the airbag system (<NUM>) and the external device (<NUM>) is not successful, the control unit (<NUM>) of the airbag system (<NUM>) is configured to put the airbag system (<NUM>) in an idle state and/or to alert the user (<NUM>) to manually change to an idle state, and
if the communication between the airbag system (<NUM>) and the external device (<NUM>) is successful, the control unit (<NUM>) of the airbag system (<NUM>) is configured to put the airbag system (<NUM>) in an active state and/or to alert the user (<NUM>) to manually change to an active state.