WO2014155402A2

WO2014155402A2 - An electromagnetic device for guiding of a partially-sighted or blind user.

Info

Publication number: WO2014155402A2
Application number: PCT/IT2014/000078
Authority: WO
Inventors: Lorenzo Scalise; Valter MARIANI PRIMIANI; Paola Russo; Alfredo DE LEO; Graziano CERRI
Original assignee: Universita' Politecnica Delle Marche
Priority date: 2013-03-27
Filing date: 2014-03-26
Publication date: 2014-10-02
Also published as: ITAN20130065A1; WO2014155402A3

Abstract

The device (1 ) for guiding a partially-sighted or blind person (X) without contact along a trajectory or route comprises a transmitter (T), comprising two transmitting antennas (A1, A2), adapted to form two electromagnetic barriers (B1. B2) perpendicular to a street plane and separated by an adjustable distance (Z) and also comprises a receiver (R) worn by the person (X) and comprising two alarm devices (Y1, Y2) adapted to generate an alarm when the person (X) gets close to one of said two electromagnetic barriers ( B1, B2).

Description

An electromagnetic device for guiding of a partial ly-sighted or blind user.

The present patent application for industrial invention relates to an electromagnetic device for guiding without contact a partially-sighted or blind person along a trajectory or route.

In particular, the device of the invention has been devised in order to guide athletes along a trajectory or route free of obstacles, in such manner that the athletes can carry out their activity safely and autonomously.

Although the present description refers to an electromagnetic guiding device for athletes, the protection scope of the invention is not to be considered as limited to the electromagnetic devices used in sports.

i n other words, the device of the invention has the same advantages when used to guide blind persons or persons with a severe sight disability during their daily activities.

The number of inventions aimed at allowing blind persons or persons with a severe sight disability to play sports, both at amateur a nd professional level, in spite of the fact that sight is extremely important practically in ail sports disciplines.

I n particular, the most popular sports for blind persons or persons with a severe sight disability include track and field, swimming and skiing .

For example, in track and field, both during competitions and practice sessions, each athlete with a visual disability is accompanied by a non- disabled athlete to whom he/she is tied with a string.

More precisely, the string has a noose at each end: a first noose is used to receive the hand of the blind athlete, whereas a second noose is used to receive the hand of the non-disabled athlete that accompanies the blind athlete.

The length of the string depends on the freedom of movement that the guide of the blind athlete wants to give to the latter during the competition or practice session.

In fact, the shorter the string, the easier will be for the athlete to follow the movements of his/her guide, who guides and gives directions to the athlete so that the running trajectory does not deviate from the route.

The blind or partially-sighted persons can also ski by means of a recent technique that is based on a sort of radio-controlled downhill descent, in which an instructor precedes the athlete during the downhill descent and gives him/her orders through a transceiver connected to radio headphones worn on the athlete's head.

In such a guide technique, the ability of the instructor lies in timing the controls given to the blind skier according to his/her speed and reactiveness, as well as according to the distance between distance between the blind athlete and the instructor.

It must be noted that, in order to allow non-disabled skiers to immediately recognize a blind skier and guarantee the safety of the blind skier, the latter wears a chest vest with a bright color that says "blind" on both sides.

Moreover, it must be noted that the ski runs must be practically empty or in any case not crowded in order to reduce the risk of accidents, the number of which increases in direct relation to the number of skiers, and in order to allow the blind skier to concentrate on the instructions given by the instructor without background interference that may distract or confuse him/her.

In fact, although the instructions given by the instructor can be easily distinguished also in bad weather conditions, for example in case of strong wind, the voice of the instructor must not be surpassed by the external noise that is inevitably generated in case of crowded ski runs.

Moreover, the ski runs must be long, smooth and gentle in such manner that blind athletes can have enough time to process the instructions given by the instructor and make the curves at a relatively low speed.

With reference to swimming, because of the presence of floating buoys that define the lane of the swimming pool, when swimming in the proximity of said buoys, the blind athlete receives the necessary directional inputs.

Unlike the aforementioned sports, in swimming each blind athlete is advantageously followed by two instructors, each of them, by touching the head or the shoulders of the blind athlete with a specific tool composed of a rod with a soft, elastic support fixed at one end. informs the blind athlete that is proximal to the end of the swimming pool in order to get him/her ready to turn.

With reference to blind marathon athletes, given the long duration of the race, each athlete is advantageously followed both during the competition and the practice session by a team of about four non-disabled athletes that alternate beside the blind athlete in order to reassure him/her through the route to be covered.

From the above it appears evident that each sport played by partially- sighted or blind athletes requires the presence of a guide that assists the blind athlete both during the practice sessions and the competitions, as well as a perfect synchronism between the athlete and the guide.

Consequently, the athlete and the guide must always train together, in order to get familiar with their movements both for the athlete and the guide.

Therefore, the blind athletes are currently obliged to play sports in the presence of at least one non-disabled athlete, th us limiting the personal freedom of the blind athlete. The purpose of the present invention is to remedy the drawbacks of the prior art by devising a guiding device for partially-sighted and blind athletes that allows them to free themselves from their instructor and participate in competitions or practice sessions without their guide/instructor.

The electromagnetic device for guiding a blind or partially-sighted person without contact along a trajectory or route comprises a transmitter and a receiver, which are respectively adapted to irradiate and receive electrical signals.

The transmitter comprises:

a generator that generates an original electrical carrier signal; a first electrical signal divider installed downstream said generator to divide the original electrical carrier signal into a first electrical carrier signal and a second electrical carrier signal;

a first modulator and a second modulator, each of them being disposed in a transmission channel, downstream said first signal divider, to modulate said first and second electrical carrier signals and obtain a first and second modulated signal;

a first transmitting antenna and a second transmitting antenna, each of them being arranged on a transmission channel downstream the first and second modulator to convert said first and second modulated signal in two beams in radiated electromagnetic field, which are adapted to form two electromagnetic barriers perpendicular to a street plane and separated by an adjustable distance.

The receiver comprises:

a receiving antenna that receives said first modulated signal or said second modulated signal coming out of one of said two transmitting antennas; a demodulator downstream the receiving antenna to receive in input the modulated signal captured by said receiving antenna and provide in output a original demodulated signai;

a second signal divider downstream said demodulator to receive in input the original demodulated signal and divide the original demodulated signal into a first demodulated signal and a second demodulated signal;

two band-pass filters installed in parallel downstream said second signal divider to respectively filter said first and second demodulated signal and provide in output a first filtered signal and a second filtered signal, respectively.

a comparator downstream said two band-pass filters to compare the width of each of said two filtered signals with a preset threshold value and generate a control signal when the width of one of said two filtered signals exceeds said preset threshold value;

two alarm devices installed in parallel and downstream said comparator to receive said control signal emitted by the comparator and generate an alarm.

For explanatory reasons the description of the device according to the present invention continues with reference to the attached drawings, which only have an illustrative, not limiting value, wherein;

- Fig. 1 is a block diagram showing the transmitter of the device of the invention;

- Fig. 2 is a block diagram showing the receiver of the device of the invention;

Figs. 3 and 4 are two diagrammatic views showing the operation of the device of the invention.

Referring to Figs. 1 and 2. the device (1 ) of the invention comprises a transmitter (T) and a receiver (R), respectively adapted to irradiate and receive eiectricai signals with frequency comprised between 3 GHz and 300 GHz.

The transmitter (T) comprises:

a generator (G);

5 - a first eiectricai signal divider (D1 ) situated downstream the generator (G);

two modulators (M1 , M2). of which a first modulator (M1 ) and a second modulator (M2), each of them situated in a transmission channel downstream the first signal divider (D1 );

10 - two transmitting antennas (A1 , A2), of which a first transmitting antenna (A1 ) and a second transmitting antenna (A2), each of them being disposed on a transmission channel downstream the two modulators (M 1 , M2).

The operation of the transmitter (T) of the device (1 ) of the invention is i s disclosed hereinafter.

The generator (1 ) generates an original electrical carrier signal (S) that can be represented as a sinusoidal signal in time domain:

Sp(t) - A cos(2nfpt)

wherein (A) is the width and (fp) is the frequency of the original0 electrical carrier signal (Sp).

The frequency (fp) of said original eiectricai carrier signal (Sp) is comprised between 3 GHz and 300 GHz, preferably in the 10-30 GHz band.

The generator (G) sends the original eiectricai carrier signal (Sp) to the first signal divider (D1 ), which divides the original electrical carrier signal5 (Sp) into a first eiectricai carrier signal (Sp1 ) and a second electrical carrier signal (Sp2) that are identical:

Sp1 (t) = Sp2(t) = Sp(t) /2= A72 cos(2Trfpt). The first electrical carrier signal (Sp1 ) is sent to the first modulator (M1 ) and the second electrical carrier signal (Sp2) is sent to the second modulator ( 2).

The first modulator (M1 ) modulates the first electrical carrier signal (Sp1 ) by means of a first modulating signal (Sm1 ) with a frequency (f1 ).

The second modulator (M2) modulates the second electrical carrier signal (Sp2) by means of a second modulating signal (Sm2) separated from said first modulating signal (Sml ) and having a frequency (f2).

The frequency (f1 ) of the first modulating signal (Sm1) and the frequency (f2) of the second modulating signal (Sm2) are much lower than the frequency (fp) of the original electrical carrier signal (Sp).

The first modulator (M1) provides in output a first modulated signal (S1 ) and sends said first modulated signal (S1) to the first transmitting antenna (A1 ).

The second modulator ( 2) provides in output a second modulated signal (S2) and sends said second modulated signal (S2) to the second transmitting antenna (A2).

The two transmitting antennas (A1 , A2) respectively convert the first modulated signal (S1 ) and the second modulated signal (S2) in two beams in radiated electromagnetic field (Sri Sr2), adapted to form two electromagnetic barriers (Bl B2) perendicular to a street plane and separated by an adjustable distance (Z), as shown in Fig. 3.

Advantageously, said distance (Z) between the two electromagnetic barriers (B1 , 62) formed of the two beams in radiated electromagnetic field (Sr1 , Sr2) generated by the two transmitting antennas (A1 , A2) is comprised between 1 m and 3 m.

Specifically, said distance (Z) is preferably 2 m.

Consequently, the distance between the two transmitting antennas (A1 , A2) must be such to ensure that the distance (Z) between the main radiation directions of the two beams in radiated electromagnetic field (Sr1 , Sr2) is equai to the set value.

Each of the two beams in radiated electromagnetic field (Sr1 , Sr2) generated by the two transmitting antennas (A1 , A2) is advantageously a broadside beam with:

a narrow width (for example defined by an angle comprised between 2 and 10°) on a horizontal plane;

a high width (for example defined by an angle comprised between 50° and 1 00°) on a vertical plane.

Such widths of the beams have been devised to cover a person (X) with medium-sized body.

The receiver (R) comprises:

a receiving antenna (R 1 );

a demodulator (D) downstream the receiving antenna;

a second signal divider (D2) downstream the modulator (D); two pass-band filters (F1 , F2) disposed in parallel downstream the second signal divider (D2);

a comparator (C) downstream said pass-band filters (F1 , F2); two alarm devices (Y1 , Y2) installed in parallel and downstream said comparator (C).

The operation of the receiver (R) of the device (1 ) of the invention is disclosed hereinafter.

The receiving antenna (R1 ) receives the first modulated signal (S1 ) or the second modulated signal (S2) radiated from the two transmitting antennas (A1 , A2) of the transmitter (T) and sends them to the demodulator (D).

The demodulator (D) receives in input the modulated signal (S1 , S2) captured by the receiving antenna (R 1 ) and provides in output an original demodulated signal (Sd) with the same frequency (f1 ) as the first modulating signal (Sm1 ) or the same frequency (f2) as the second modulating signal (Sm2).

More precisely, the original demodulated signal (Sd) has the frequency (f1 ) of the first modulating signal (Sm1 ), if the demodulator (D) 5 receives in input the first modulated signal (S1 ), or the frequency (f2) of the second modulating signal (Sm2) if the demodulator (D) receives in input the second modulated signal (S2).

The demodulator (D) sends the original demodulated signal (Sd) to the second signal divider (D2) that divides the original demodulated signal so (Sd) into a first demodulated signal (Sd1 ) and a second demodulated signal (Sd2) that are identical.

More precisely, if the original demodulated signal (Sd) has the frequency (f1 ) of the first modulating signal (Sm1 ), the first demodulated signal (Sd1 ) and the second demodulated signal (Sd2) are identical and i s have the frequency (f1 ) of the first modulating signal (Sm1 ):

Sd1 (t) = Sd2(t) = Sd(t) 12= A/2 cos(27Tfit),

Vice versa, if the original demodulated signal (Sd) has the frequency (f2) of the second modulating signal (Sm2), the first demodulated signal (Sd1 ) and the second demodulated signal (Sd2) are identical and have the 0 frequency (f2) of the second modulating signal (Sm1 ):

Sd1 (t) = Sd2(t) = Sd(t) 12= A/2 cos(2nf₂t)

The first pass-band filter (F1 ) and the second pass-band filter (F2) respectively filter the first demodulated signal (Sd1 ) and the second demodulated signal (Sd2) generated by the second signal divider (D2) and 5 respectively provide in output a first filtered signal (Sf1 ) and a second filtered signal (Sf2).

The first pass-band filter (F1 ) has a frequency band centered on the frequency (fl ) of the first demodulated signal (Sd1 ). The second pass-band filter (F2) has a frequency band centered on the frequency (f2) of the second demodulated signal (Sd1 ).

For illustrative purposes, the frequency band of the first pass-band filter (F1 ) has a band center value of 1 kHz and the frequency band of the second pass-band filter (F2) has a band center value of 10 kHz.

The frequency band of the two pass-band filters (F 1 , F2) is 30% calculated at -1 0 dB with respect to the band center value.

The filtered signals (Sf1 . Sf2) in output from the two pass-band filters (F1 , F2) are sent to the comparator (C) that compares the width of each of said two filtered signals (Sf 1 . Sf2) with a set threshold value.

Advantageously, said threshold value is comprised between 20% and 40% of the maximum value of the signal that is received when the receiving antenna (R1 ) is aligned with the transmitting antenna (A1 , A2).

If the width of one of said two filtered signals (Sf 1 . Sf2) exceeds the set threshold value, the comparator (C) sends a control signal (C 1 ) to one of the two alarm devices (Y1 , Y2), which generates an alarm to inform the person (X) about the proximity of one of the two electromagnetic barriers (B1 , B2) that define the route to be covered

It must be noted that the two alarm devices (Y1 , Y2) may include acoustic warning signals or vibration warning signals, provided with means, the vibration of which is perceived as alarm by the person.

Referring to Fig 4, the receiver (R) is worn by the blind person (X), whereas the transmitter (T) is mounted on a support advantageously disposed on a vehicle that precedes the person (X) by a few meters (from 5 m to 10 m) along the competition or practice route.

The receiver (R) informs the person (X) his/her deviation with respect to the route, which is defined by the two electromagnetic barriers (B1 . B2) generated by the two transmitting antennas (A1 , A2) of the transmitter (T), as shown in Fig. 3. More precisely, if the person (X) remains in the center of the route defined by the two electromagnetic barriers (B1 , B2) generated by the two transmitting antennas (A1 , A2). the modulated signal (S1 , S2) received by the receiving antenna (R1 ) is very low.

Vice versa, if the person (X) gets close to one of the two electromagnetic barriers (B 1 . B2), the modulated signal (S1 , S2) received by the receiving antenna (R1 ) increases and has a width in inverse relation to the distance between the person (X) and the electromagnetic barrier (B 1 , B2) and in direct relation to the directive gain of the transmitting antennas (A1 , A2) calculated in the direction that, starting from each of said two transmitting antennas (A1 , A2), intercepts the person (X).

Referring to Fig. 3, if the person (X) moves to the left side of the route, according to the traveling direction, he/she enters the radiation lobe of the second transmitting antenna (A2).

in such a case, the second filtered signal (Sf2) coming out of the second pass-band filter (F2) has an intensity that depends on the position of the person (X) with respect to the maximum radiation direction of the second transmitting antenna (A2), whereas the first filtered signal (Sf 1 ) coming out of the first pass-band filter (F1 ) has a negligible intensity

Evidently, the second filtered signal (Sf2) coming out of the second pass-band filter (F2) has a maximum intensity when the person (X) is positioned exactly in the maximum radiation direction of the second transmitting antenna (A2).

Vice versa, if the person (X) moves to the right side of the route, according to the traveling direction, he/she enters the radiation lobe of the first transmitting antenna (A1 ).

In such a case, the first filtered signal (Sf 1 ) coming out of the first pass-band filter (F1 ) has an intensity that depends on the position of the person (X) with respect to the maximum radiation direction of the first transmitting antenna (A1 ), whereas the second filtered signal (Sf2) coming out of the second pass-band filter (F2) has a negligible intensity.

Evidently, the first filtered signal (Sf1 ) coming out of the first pass- band filter (F1 ) has a maximum intensity when the person (X) is positioned exactly in the maximum radiation direction of the first transmitting antenna (A1 ).

It must be noted that the alarm generated by the alarm devices (Y1 _« Y2) is advantageously different whether the person (X) gets close to the electromagnetic barrier (B1 , B2) situated on his/her right or left side, in such manner to let the person (X) perceive his/her position with respect to the center of the route to be covered.

Consequently, by capturing the alarm signal, the blind person (X) corrects his/her running trajectory and positions himself/herself back in the center of the route defined by the two electromagnetic barriers (B1 , B2) generated by the two transmitting antennas (A1 , A2),

It must be noted that the possibility to use a wide range of signal frequencies, comprised between 3 GHz and 300 GHz, allows to considerably reduce the dimensions of the components of the device (1 ) of the invention, which are therefore lightweight, easy to wear and advantageously integrated with ordinary clothes, such as belts, hats or jackets worn by the person (X) during a competition or a practice session, with higher comfort for the athlete.

More precisely, the device of the invention can be worn by the person (X) under his/her clothes because the electromagnetic waves penetrate the fabric used for clothes; a similar performance allow the person (X) to take advantage of all benefits offered by the invention without impairing his/her image at the observer's eyes. Moreover, it must be noted that the device of the invention does not require a special ability by the person (X) or the use of complicated training procedures for use.

Claims

1 ) Electromagnetic device (1 ) for guiding a blind or partially- sighted person (X) without contact along a trajectory or route comprises a transmitter and a receiver, which are respectiveiy adapted to irradiate and receive electrical signals.

said transmitter (T) comprising:

a generator (G) that generates an original electrical carrier signal (Sp);

a first electrical signal divider (D1 ) installed downstream said generator (G) to divide the original carrier electrical signal (Sp) into a first eiectrical carrier signal (Sp1 ) and a second electrical carrier signal (Sp2);

a first modulator (M 1 ) and a second modulator (M2), each of them being disposed in a transmission channel downstream said first signal divider (D1 ) to moduiate said first and second electrical carrier signals (Sp1 ; Sp2) and obtain a first and second modulated signal (S1 , S1 );

a first transmitting antenna (A1 ) and a second transmitting antenna (A2), each of them being arranged on a transmission channel downstream the first and second modulator (M1 , M2) to convert said first and second modulated signal (S1 , S2) in two beams in radiated electromagnetic field (Sr1 , Sr2) adapted to form two electromagnetic barriers (B1 , B2) perpendicular to a street plane and separated by an adjustable distance (Z);

said receiver (R) comprising:

a receiving antenna (R1 ) that receives said first modulated signal (S1 ) or said second modulated signal (S2) coming out of one of said two transmitting antennas (A1 , A2); a demoduiator (D) downstream the receiving antenna (R1 ) to receive in input the modulated signal (S1 , 82) captured by said receiving antenna (R1 ) and provide in output a original demoduiated signal (Sd);

a second signal divider (D2) downstream said demodulator (D) to receive in input the original demoduiated signal (Sd) and divide the original demoduiated signal (Sd) into a first demodulated signal (Sd1 ) and a second demoduiated signal (Sd2);

two band-pass filters (F1 , F2) installed in parallel downstream said second signal divider (D2) to respectively filter said first and second demodulated signal (Sd1 ; Sd2) and provide in output a first filtered signal (Sf1 ) and a second filtered signal (Sf2), respectively;

a comparator (C) downstream said two band-pass filters (F1 , F2) to compare the width of each of said two filtered signals (Sf1 , Sf2) with a preset threshold value and generate a control signal (C1 ) when the width of one of said two filtered signals (Sf l . Sf2) exceeds said preset threshold value;

two alarm devices (Y Y2) installed in parallel and downstream said comparator (C) to receive said control signal (C1 ) emitted by the comparator (C) and generate an alarm.

2) The device (1 ) of claim 1 , wherein said transmitter (T) and said receiver (R) are set in such manner to irradiate and receive respectively electrical signals with frequency from 3 GHz to 300 GHz.

3) The device (1 ) of claim 1 or 2, wherein said bearing original electrical signal (Sp) has frequency (fp) from 10 GHz to 30 GHz,

4) The device (1 ) of any one of the preceding claims, wherein each of said two beams in radiated electromagnetic field (Sri , Sr2) is a broadside beam having:

width defined by an angle comprised between 2° and 10" on a horizontal plane; width defined by an angle comprised between 50° and 100° along a vertical plane;

5) The device (1 ) of any one of the preceding claims, wherein said distance (Z) between said two electromagnetic barriers (B 1 . B2) is comprised between 1 m and 3 m

6) The device (1 ) of any one of the preceding claims, wherein said first pass-band filter (F1 ) has a frequency band with band center value of 1 kHz and said second pass-band filter (F2) has a frequency band with band center value of 10 kHz.

7) The device (1 ) of any one of the preceding claims, wherein said preset threshold value, which is used by the comparator (C) to compare the width of each of said two filtered signals (Sf 1 , Sf2), is comprised between 20% and 40% of the maximum value of the signal received by the receiver (R) when said receiving antenna (R1 ) is aligned with the transmitting antenna (A1 , A2).

8) The device (1 ) of any one of the preceding claims, wherein said two alarm devices (Y1 , Y2) are acoustic and/or vibration alarms.

9) Use of a device ( 1 ) according to any one of the preceding claims, wherein said receiver (R) is worn by the blind user (X) and wherein the transmitter (T) is mounted on a support disposed on a vehicle adapted to precede the user (X) by 5 - 1 0 m during the route.

10) A method for guide without contact of a partially-sighted or blind user (X) along a trajectory or route, comprising the following steps:

generate a bearing originary electrical signal (Sp); divide said bearing originary electrical signal (Sp) into a first bearing originary electrical signal (Sp1 ) and a second bearing originary electrical signal (Sp2);

modulate said first and second electrical carrier signals (Sp1 ; Sp2) and obtain a first and second modulated signal (S1 , S2); convert said first and second modulated signal (S1 , S2) into two beams in radiated electromagnetic field (Sr1 , Sr2) adapted to form two electromagnetic barriers (B1 , B2) perpendicular to a street plane and separated by a an adjustable distance (Z);

- receive said first modulate signal (S1 ) or said second modulated signal (S2);

demodulate the modulated signal (S1 , S2) and generate an original demodulated signal (Sd);

receive the original demodulated signal (Sd) and divide the original demodulated signal (Sd) into a first demodulated signal (Sd1 ) and a second demodulated signal (Sd2);

filter said first and second demodulated signal (Sd1 ; Sd2), respectively, and generate a first filtered signal (Sf1 ) and a second filtered signal (Sf2), respectively;

- compare the width of each of said two filtered signals (Sf1 , Sf2) with a preset threshold value and generate a control signal (C1 ) when the width of one of said two filtered signals (Sf 1 , Sf2) exceeds said preset threshold value;

receive said control signal (C1 ) and generate an alarm.