EP3489927A1

EP3489927A1 - Warning device

Info

Publication number: EP3489927A1
Application number: EP17204118.8A
Authority: EP
Inventors: Tommy Ekman; Basim ALI; Stefan BANÉR
Original assignee: Semcon Sweden AB
Current assignee: Semcon Sweden AB
Priority date: 2017-11-28
Filing date: 2017-11-28
Publication date: 2019-05-29

Abstract

A warning device (2) for a driver of a vehicle (4), comprising a housing (6) having an extension along a main axis A, and a first end (8) and a second end (10) at opposite ends of the housing (6) along said main axis A, the warning device comprises an attachment member (12) structured to attach said warning device at the vehicle (4). The housing (6) is structured to enclose a radio signal detection unit (14) configured to detect a radio signal (16) and to generate a sensor signal (18) in dependence of a detected radio signal; a processing unit (20) configured to receive said sensor signal (18) and to continuously determine a predetermined signal measure of said radio signal, a warning signal generator (24) arranged e.g. at said first end (8) and configured to generate a warning signal (26). The radio signal detection unit (14) comprises a directional antenna (28) mounted such that it has a main detection lobe (30) in the direction of said first end (8) and configured to detect said radio signals within said main detection lobe. The processing unit (20) is configured to compare the signal measure to at least one predetermined threshold value which is determined at least in relation to a distance d_thres between a radio generating device (32) and the warning device (2), and the processing unit (20) is further configured to control the warning signal generator (24) to generate the warning signal (26) in response of the result of said comparison.

Description

Technical field

The present disclosure relates to a warning device according to the preamble of claim 1. The warning device is generally within the technical field of preventing accidents between cycles and other vehicles, e.g. motor vehicles (cars, trucks etc.), and in particular for preventing so-called dooring accidents between cycles and other vehicles. A cycle should herein be interpreted to comprise cycles, electrical cycles, motorcycles, and other vehicles.

Background

The number of cyclist increases, and then also the number of accidents where cyclists are being injured, or even killed. One specific situation that is potentially dangerous to cyclists is when cycling close to and along a line of parked cars and cars standing still in slow traffic, where a door of a car is opened when the cycle passes (e.g. "dooring").
In WO2011/137477 is a cyclist proximity warning system disclosed that is applicable in situations when a driver's door is opened into the path of a cyclist. A receiver for the proximity warning signal at the vehicle may be a Bluetooth receiver to identify a cyclist transmitter unit, and the in-vehicle unit may be adapted to identify a detected Bluetooth device as a cyclist proximity warning device and this recognition triggers the alert without requiring a full communication connection to be established between the two devices. The proximity warning signal sent from the transmitter unit at the bicycle is an optical signal, or a radio frequency signal.
The object of the warning device according to the present invention is to achieve an improved functionality that does not require a dedicated unit mounted at the bicycle and that the warning device is adapted to the specific situation when a cycle moves along a line of stopped vehicles.

Summary

The above-mentioned object is achieved by the present invention according to the independent claim.
Preferred embodiments are set forth in the dependent claims.
Thus, a warning device for persons in a vehicle is disclosed that comprises a housing having an extension along a main axis A, and a first end and a second end at opposite ends of the housing along said main axis A. The warning device comprises an attachment member structured to attach the warning device at the vehicle. The warning device is self-contained, i.e. it does not require any external connection for energy supply.
The housing is structured to enclose a radio signal detection unit configured to detect a radio signal and to generate a sensor signal in dependence of a detected radio signal; a processing unit configured to receive said sensor signal and to determine a predetermined signal measure of said radio signal; an energy source capable of supplying energy to the warning device, and a warning signal generator arranged at said first end and configured to generate a warning signal; e.g. a visual, audible and/or tactile warning signal.
The radio signal detection unit comprises a directional antenna mounted such that it has a main detection lobe in the direction of the first end and configured to detect the radio signals within the main detection lobe. The processing unit is configured to compare the signal measure to at least one predetermined threshold value which is determined at least in relation to a distance d_thres between a radio generating device and the warning device, and that the processing unit is further configured to generate a control signal to control the warning signal generator to generate the warning signal in response of the result of the comparison.
According to one embodiment the main detection lobe has a maximal extension of a semi-sphere limited by a limitation plane extending essentially perpendicularly to said axis A. This is advantageous in that detection is limited to detect radio generating device located behind and beside the warning device when mounted at a vehicle having the main detection lobe directed backwards, i.e. the number of falsely generated warning signals is minimized.
According to another embodiment the directional antenna is integrated into the housing, e.g. into a wall of said housing. This embodiment enables that the warning device may be an easy-handled and compact device.
According to one embodiment the warning signal is a visual warning signal, and that the warning signal generator is arranged at the first end and comprises at least one light emitting diode. The warning signal is preferably a flashing light. It is advantageous to arrange the warning signal generator at the first end of the warning device such that the direction of the visual warning signal essentially coincides with the direction of the main lobe of the directional antenna, because when the warning device is mounted at an outer rear view mirror with the main axis A directed backwards a person sitting in the driver seat in the vehicle will easily notice the visual warning signal, which also is directed backwards..
According to still another embodiment the radio signal is a Bluetooth low energy (BLE) signal. This is advantageous as many cyclists bring their Bluetooth-activated mobile phone which then is the radio signal generating device, and thus no separate dedicated device is required.
In still a further embodiment the warning device comprises a movement sensor capable of detecting movement of the warning device and to generate a movement sensor signal which is applied to the processing unit. The warning device is configured to be in a sleep mode, which is a low energy consuming mode, when movement is detected by the movement sensor, and in an active mode when no movement is detected. In the active mode the warning device is activated and enabled for detecting radio signals and generating warning signals. This is advantageous in order to achieve a self-contained low-energy consuming device.
According to another embodiment, the attachment member is structured to attach the warning device at an outer rear view mirror of a vehicle, in a predetermined orientation such that the first end essentially faces backwards in relation to said vehicle's driving direction. This is an optimal position in order to warn both the driver of the vehicle and also the cyclist.
Generally, the present invention relates to a warning device configured to be attached at a rear view mirror of a vehicle, and to generate a warning signal, e.g. a visible signal (e.g. a flashing light), an audible signal and/or a tactile signal, when a bicycle is approaching from behind. The warning signal is generated when the vehicle is standing still and is intended to make the driver of the vehicle aware of an approaching cyclist and then warn the driver in order to prevent the driver from opening the door of the vehicle.
A presumption for the warning device to detect an approaching cyclist is that the cyclist has a radio signal generating device, e.g. a mobile phone (a smartphone) or another transmitter, enabled to actively send out radio signals, e.g. Bluetooth signals.

Brief description of the drawings

Figure 1 is a schematic illustration from above of a vehicle provided with a warning device according to the present invention.
Figure 2 is a schematic block-diagram of a warning device according to the present invention.
Figure 3 is a perspective view illustrating the warning device according to an embodiment of the present invention.
Figure 4 is an enlarged view of the warning device illustrated in figure 3.
Figure 5 is a side view illustrating the warning device according to another embodiment of the present invention.
Figure 6 is a perspective view of the warning device shown in figure 5.
Figure 7 illustrates the embodiment shown in figures 5 and 6 mounted at an outer rear view mirror of a vehicle.
Figure 8 is a perspective view that illustrates still another embodiment of the warning device according to the present invention.
Figure 9 illustrates the embodiment shown in figure 8 mounted at an outer rear view mirror of a vehicle.

Detailed description

The warning device will now be described in detail with references to the appended figures. Throughout the figures the same, or similar, items have the same reference signs. Moreover, the items and the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
With references for figures 1 and 2, a warning device 2 is disclosed for persons in a vehicle 4, e.g. a car, a truck or any other vehicle. The warning device 2 comprises a housing 6 having an extension along a main axis A, and a first end 8 and a second end 10 at opposite ends of the housing 6 along said main axis A,
The warning device comprises an attachment member 12 structured to attach the warning device at the vehicle 4. In one embodiment illustrated in figures 1, 3 and 4, the warning device is attached at an outer rear view mirror of the vehicle.
The housing 6 is structured to enclose a radio signal detection unit 14 configured to detect a radio signal 16 and to generate a sensor signal 18 in dependence of a detected radio signal.
The housing is further structured to enclose a processing unit 20 configured to receive the sensor signal 18 and to determine, preferably continuously, a predetermined signal measure of the radio signal. The housing also encloses an energy source 22 capable of supplying energy to the various parts of the warning device, and a warning signal generator 24, preferably arranged at the first end 8, and configured to generate a warning signal 26, essentially in a direction along the axis A.
Preferably, the warning device has a planar elongated shape along axis A, and it has a maximum length along axis A of 100 mm, a maximum width of 50 mm, and a maximum height of 20 mm. In one embodiment the length is approximately 85 mm, the width is 35 mm, and the height is 10 mm.
The housing 6 is made from a waterproof material, e.g. any suitable plastic material that preferably is slightly flexible in order to smoothly adapt to the surface it is intended to be attached to.
The radio signal detection unit 14 comprises a directional antenna 28 mounted such that it has a main detection lobe 30 in the direction of the first end 8 of the housing, and configured to detect the radio signals within the main detection lobe. As stated above, in one embodiment the attachment member 12 is structured to attach the warning device at an outer rear view mirror 40 of a vehicle (see figures 1, 3 and 4). The warning device is then attached in a predetermined orientation such that the first end essentially faces backwards in relation to the vehicle's driving direction. This is advantageous in order to detect a cyclist coming from behind, and also for the visibility of the generated warning signal, which may be seen both by the driver of the vehicle and also by the cyclist.
In a further variation of the warning device, the directional antenna has one or many additional detection lobes directed in predefined directions in relation to axis A. In one example an additional detection lobe may be directed in an opposite direction, i.e. along axis A, compared to the direction of the main lobe. In another example an additional detection lobe may be directed along a line running at an angle of approximately 45 degrees to axis A in the direction of the second end of the warning device.
The processing unit 20 is configured to compare the signal measure to at least one predetermined threshold value which is determined at least in relation to a distance d_thres between a radio signal generating device 32, e.g. a Bluetooth enabled smartphone, or any other transmitter, carried by a cyclist (see figure 1), and the warning device 2. The processing unit 20 is further configured to generate a control signal 34 to control the warning signal generator 24 to generate the visual warning signal 26 in response of the result of the comparison.
The processing unit 20 is e.g. a microprocessor and has the necessary processing capability to perform e.g. calculations, comparisons, signal processing, etc. It comprises a memory part having a storage capacity where threshold values, processing algorithms, etc. may be stored. The processing unit is also adapted to receive external programming instructions, e.g. for setting threshold values.
The predetermined signal measure may be any measure of the signal being related to a distance to a signal transmitter, e.g. the power of the detected signal. According to one example, a so-called received signal strength indicator (RSSI) is applied, which is a measurement of the power present in a received radio signal. RSSI is often used in telecommunication systems. However, because signal strength can vary greatly and affect functionality in wireless networking, IEEE 802.11 devices often make the measurement available to users. RSSI is often derived in the intermediate frequency (IF) stage before the IF amplifier. In zero-IF systems, it is derived in the baseband signal chain, before the baseband amplifier. RSSI output is often a DC analog level. It can also be sampled by an internal ADC and the resulting codes available directly or via peripheral or internal processor bus. In an IEEE 802.11 system, RSSI is the relative received signal strength in a wireless environment, in arbitrary units. RSSI is an indication of the power level being received by the receive radio after the antenna and possible cable loss. Therefore, the higher the RSSI number, the stronger the signal. Thus, when an RSSI value is represented in a negative form (e.g. -100), the closer the value is to 0, the stronger the received signal has been.
A related power indicator, which also is applicable herein, is the so-called received channel power indicator (RCPI). RCPI is an 802.11 measure of the received radio frequency power in a selected channel over the preamble and the entire received frame, and has defined absolute levels of accuracy and resolution.
According to another example, which is applicable when the radio signal is sent using the so-called Bluetooth Low Energy (BLE) protocol, the detection threshold is set such that a BLE message is detected within a specified distance from the warning device, in the desired range, which may be in the range of 5-15 meter. The use of Bluetooth signals will be further discussed below.
According to one embodiment the main detection lobe 30 has a maximal extension of a semi-sphere limited by a limitation plane extending essentially perpendicularly to the axis A.
In a further embodiment the antenna 28 has a maximal detection range d_max of 100 meter along the main axis A, and in another embodiment the maximal detection range is within the range of 40-80 meter.
Preferably, the directional antenna 28 comprises a dipole antenna and a reflector plane. The directional antenna 28 may be an integrated part of the wall of the housing 6.
The radio signal may be a Bluetooth signal, which is generated, as mentioned above, by a Bluetooth enabled radio signal generating device 32, which preferably is a smartphone.
In one further variation the directional antenna may have a main detection lobe that is asymmetrical with regard to the axis A. As an example, if the warning device is intended to be attached to the left side of the car, e.g. at the left outer rear view mirror, it would be advantageous if the main detection lobe has an extension limited by a limitation line running in the direction of axis A, and a limitation line running approximately in a perpendicular direction to the left in relation to the car's driving direction. Thereby, a detection lobe optimized for detecting cyclists behind and outside the car would be achieved. If instead the warning device is mounted on the right side of the car, a warning device provided with a right-sided main detection lobe could be applied.
The predetermined threshold value is determined to correspond to a distance, d_thres, along the axis A, in the desired range, preferably in the range of 5-15 m. When the signal measure exceeds the threshold value the processing unit 20 is configured to control the warning signal generator 24 to generate the warning signal 26.
The threshold value may also be variable such that the threshold value depends upon a speed of the radio signal generating device 32, e.g. the cyclist. If the cyclist has a higher speed the distance between the radio signal generating device 32 and the warning device 2 must be longer when the visual warning signal is generated in comparison to a situation where the cyclist has a rather low speed.
Preferably, the warning signal is generated as long as the signal measure exceeds the threshold value. As an alternative, the duration of generating the warning signal is set to a predetermined time period, e.g. in the range of 2-4 seconds.
In one embodiment the warning signal is a visual warning signal. The warning signal generator 24 then comprises at least one light emitting diode, emitting e.g. white light, red light, blue light, or orange light, and that the warning signal 26 preferably is a flashing light. Naturally, other types of light emitting units may be applied.
In another embodiment the warning signal is an audible warning signal. The audio system of the vehicle may then be applied and the processing unit 20 is adapted to send a wireless control signal to the audio system of the vehicle.
In still another embodiment the warning signal is a tactile warning signal. A dedicated vibration unit may then be provided and mounted such that a generated vibration will notify the driver, e.g. when he/she is about to open the door. In that case the vibration unit will preferably be mounted at the inner side the door. In this embodiment the processing unit 20 is adapted to generate a wireless control signal to the vibration unit to control the generation of the tactile signal.
In another variation the tactile warning signal is generated by the signal generator being arranged such that the housing, or parts of the housing, of the warning device vibrates. If the warning device e.g. is attached at any of the windscreens of the vehicle the vibration may by amplified and possible to notice by persons in the vehicle. In this variation the signal generator may be a piezo-electric circuit.
It may naturally be possible to simultaneously generate two or three of the visual, audible and tactile signals.
According to one further embodiment the warning device also comprises a movement sensor 36 capable of detecting movement of the warning device and to generate a movement sensor signal 38, in dependence of detected movement, which is applied to the processing unit 20. The movement sensor and the sensor signal is indicated by dashed lines in figure 2. The movement sensor may be a piezo-electric type accelerometer. The warning device 2 is configured to be in a sleep mode, which is a low energy consuming mode, when movement is detected by the movement sensor 36. The warning device is also configured to be in an active mode when no movement is detected. When in the active mode the warning device is activated and enabled for detecting radio signals and generating warning signals. Thus, according to this embodiment the warning device is in the active mode when no movement is detected, e.g. in a situation where the car having the warning device attached is not moving, e.g. is parked or has stopped for red light. The warning device may also, as an alternative, be set in the active mode when no movement, or a certain movement, e.g. when the vehicle drives very slowly, is detected.
In figures 3 and 4 are shown perspective views of the warning device, according to one embodiment, attached to an outer rear view mirror 40 of a car.
The housing 6 is provided with a first external main surface 42 along the main axis A and an opposite second external main surface 44 along the main axis A. During normal use, the warning device is intended to be mounted such that the first external main surface 42 is facing upwards, and consequently the second external main surface 44 is facing downwards.
The housing is further provided with a first external edge surface 46 at the first end 8, and a second external edge surface 48 at the second end 10 of the warning device, and that the edge surfaces join the main surfaces at opposite ends of the main axis A.
In figures 3 and 4 the warning device is shown mounted at a right outer rear view mirror. It is naturally possible to mount it at a left outer rear view mirror, or having several warning devices mounted at the car.
In one embodiment the housing 6 is made from two pieces, a cover part including the first external main surface 42, and a base part including the second external main surface 44, made from suitable plastic materials. These parts are joined together such that the waterproof requirement is achieved. The cover part may be made from any of polystyrene plastic, methyl metal acrylic plastic, or polycarbonate plastic. The base part may be made from any of polyamide plastic, polypropylene plastic, or polyoxymethylene plastic. These materials are of course only non-limiting examples.
The energy source may be a rechargeable battery. In one embodiment the first external main surface 42 at least partly comprises of a solar cell unit 50 configured to charge the energy source 22.
As an alternative, the energy source may be charged by connecting the warning device to a charging device, or may be wirelessly charged by inductive coupling.
In one further embodiment the attachment member 12 is a suitable adhesive, e.g. an adhesive tape, which is provided at least at a part of the second external main surface 44. As an alternative, the attachment member 12 may be any mechanical member, e.g. elastic rubber bands, magnetic connection, snap fitting, or physical hooks.
As discussed above the radio signal preferably is a Bluetooth signal. Preferably, a specific Bluetooth low energy hardware is applicable in the warning device, and is then advantageously implemented in the radio signal detection unit 14. Bluetooth Low Energy (Bluetooth LE, BLE) is a wireless personal area network technology. Compared to Classic Bluetooth, Bluetooth LE is intended to provide considerably reduced power consumption and cost while maintaining a similar communication range.
Figures 5-9 are illustrations of other embodiments of the present invention.
In these embodiments the housing 6 is essentially dome-shaped.
In figure 5 is shown a side view of a dome-shaped housing, and in figure 6 a perspective view is shown. In figure 7 the warning device 2 having the dome-shaped housing is shown mounted at an outer rear view mirror 40.
In figures 8 and 9 a further embodiment is illustrated. In this embodiment the housing is dome-shaped, and is provided with an attachment member extending outside the housing when seen from above. The attachment member 12 is provided with an adhesive at its surface intended to be attached to a surface where the warning device should be mounted. Furthermore, the upper surface of the attachment member 12, opposite of the surface provided with the adhesive, is provided with solar cells 50 connected to the energy source. The increased attachment surface is advantageous in that the warning device thereby may be firmly attached to a surface, e.g. of a rear view mirror. In addition, by arranging solar cells on the surface facing upwards, an improved charging of the energy source may be achieved by the solar cells.
The feature of extending the surface of the attachment member outside the housing as illustrated in figures 8 and 9 is applicable to all embodiments of the warning device, irrespectively of the outer shape of the housing. And also providing the upper surface of the attachment member with solar cells is applicable to the other embodiments.
The present invention is not limited to the above-described preferred embodiments. Various alternatives, modifications and equivalents may be used. Therefore, the above embodiments should not be taken as limiting the scope of the invention, which is defined by the appending claims.

Claims

A warning device (2) for persons in a vehicle (4), comprising a housing (6) having an extension along a main axis A, and a first end (8) and a second end (10) at opposite ends of the housing (6) along said main axis A, the warning device comprises an attachment member (12) structured to attach said warning device at the vehicle (4), said housing (6) is structured to enclose:
- a radio signal detection unit (14) configured to detect a radio signal (16) and to generate a sensor signal (18) in dependence of a detected radio signal,

- a processing unit (20) configured to receive said sensor signal (18) and to determine a predetermined signal measure of said radio signal,

- an energy source (22) capable of supplying energy to the warning device, and

- a warning signal generator (24) configured to generate a warning signal (26),
characterized in that said radio signal detection unit (14) comprises a directional antenna (28) mounted such that it has a main detection lobe (30) in the direction of said first end (8) and configured to detect said radio signals within said main detection lobe, wherein said processing unit (20) is configured to compare the signal measure to at least one predetermined threshold value which is determined at least in relation to a distance d_thres between a radio generating device (32) and the warning device (2), and wherein said processing unit (20) is further configured to generate a control signal (34) to control said warning signal generator (24) to generate said warning signal (26) in response of the result of said comparison.
The warning device according to claim 1, wherein the main detection lobe (30) having a maximal extension of a semi-sphere limited by a limitation plane extending essentially perpendicularly to said axis A.
The warning device according to claim 1 or 2, wherein said directional antenna (28) has a maximal detection range d_max of 100 meter along said main axis A.
The warning device according to any of claims 1-3, wherein said directional antenna (28) comprises a dipole antenna and a reflector plane.
The warning device according to any of claims 1-4, wherein said directional antenna (28) is integrated into a wall of said housing (6).
The warning device according to any of claims 1-5, wherein said radio signal is a Bluetooth low energy (BLE) signal.
The warning device according to any of claims 1-6, wherein said predetermined threshold value is determined to correspond to a distance, along said axis A, in the range of 5-15 m, and wherein when said signal strength value exceeds said threshold value the processing unit (20) is configured to control said warning signal generator (24) to generate said visual warning signal (26).
The warning device according to any of claims 1-7, wherein said warning signal is a visual warning signal, and that the warning signal generator (24) is arranged at said first end (8) and comprises at least one light emitting diode, and wherein said warning signal (26) is a flashing light.
The warning device according to any of claims 1-8, comprising a movement sensor (36) capable of detecting movement of the warning device and to generate a movement sensor signal (38) which is applied to said processing unit (20), wherein said warning device (2) is configured to be in a sleep mode, which is a low energy consuming mode, when movement is detected by said movement sensor (36), and in an active mode when no movement is detected, wherein in the active mode the warning device is activated and enabled for detecting radio signals and generating warning signals.
The warning device according to any of claims 1-9, wherein said attachment member (12) is structured to attach said warning device at an outer rear view mirror (40) of a vehicle, in a predetermined orientation such that said first end essentially faces backwards in relation to said vehicle's driving direction.
The warning device according to any of claims 1-10, wherein said housing (6) is provided with a first external main surface (42) along said main axis A and an opposite second external main surface (44) along said main axis A, and a first external edge surface (46) at said first end (8), and a second external edge surface (48) at the second end (10) of the warning device, wherein said edge surfaces join said main surfaces at opposite ends of said main axis A.
The warning device according to claim 11, wherein said attachment member (12) is an adhesive and is provided at least at a part of said second external main surface (44).
The warning device according to claim 11 or 12, wherein said energy source is a rechargeable battery, and that said first external main surface (42) comprises at least partly of a solar cell unit (50) configured to charge said energy source (22).
The warning device according to any of claims 1-13, wherein said attachment member (12) extends outside the housing when seen from above, and is provided with an adhesive at its surface intended to be attached to a surface where the warning device should be mounted, and wherein the surface of the attachment member (12) opposite of the surface provided with the adhesive, is provided with solar cells (50) configured to charge said energy source (22).
The warning device according to any of claims 1-14, wherein said housing (6) is made from a waterproof material.