JP3410412B2 - Walking aids for the visually impaired - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a walking assist device for a visually impaired person, which is attached to the visually impaired person and detects a magnet embedded in a sidewalk to notify the visually impaired person.

[0002]

Braille blocks are widely used as a means for assisting the visually impaired to walk. However, there are only two types of Braille blocks, a dot block and a rod block, and there is a problem that the amount of information that can be transmitted to a visually impaired person is small.

Therefore, as a guidance method for transmitting more information to the visually impaired, a guidance block in which a plurality of magnets are embedded at necessary locations on the sidewalk with their magnetic poles oriented differently has been proposed. When such a guide block is installed on the sidewalk, the visually impaired person detects the magnet by determining the polarity and is equipped with a walking assist device that notifies the visually impaired person that the magnet embedded in the guide block has the polarity. Can be identified and recognized. Then, the visually impaired person can obtain much information by combining the recognized magnetic poles of the magnets.

In order to detect the magnet embedded in the sidewalk in this way, a magnetic sensor such as a hall element is attached to the leg (eg, ankle) of the visually impaired person 60 as shown in FIG. 3A, for example. It is conceivable to attach the provided magnetic detection device 61. When the walking assist device 61 detects the magnets 62 and 63 embedded in the sidewalk, the visually impaired person 60 is notified by a buzzer or the like so that the visually impaired person 60 can recognize the position of the sidewalk. .

However, the magnetic sensor (for example, Hall element) provided in the walking assist device 61 has directivity, and the magnetic sensor shown in FIG.
As shown in (c), the smaller the angle θ between the magnetic sensor 5 and the burying direction of the magnet 3, the lower the magnetic flux density at the location of the magnetic sensor 5, and therefore the magnetic sensor 5 according to the following equation (1). The sensitivity S decreases.

S = Asin θ (1) However, A is a proportional constant.

Therefore, as shown in FIG. 3 (b), the visually impaired person 60 puts his foot vertically on the sidewalk (θ
= 90 degrees), the magnet 3 can be accurately detected by the magnetic sensor 5. However, as shown in FIG. 3C, when the visually impaired person 60 is walking and the foot is not perpendicular to the sidewalk (θ <90 degrees), the sensitivity S of the magnetic sensor 5 decreases. The magnet 3 cannot be detected with high accuracy, and the magnet 3 may be erroneously detected.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and it is an object of the present invention to provide a walking assist device for a visually impaired person capable of accurately detecting a magnet buried in a sidewalk. To aim.

[0009]

In order to achieve the above object, a walking assist device for a visually handicapped person of the present invention walks on a magnetic pole.
A walk for a visually handicapped person who has a magnetic detection means for detecting a magnet embedded in a sidewalk toward a surface and is provided on a leg of a visually impaired person, and gives a notification when the magnet is detected by the magnetic detection means. In the auxiliary device, landing detection means for detecting that the leg is in a landed state, and the magnetic detection means only when the landing detection means detects that the leg is in a landed state And a magnetic detection permission unit that permits the detection of the magnet . And the book
A walking assist device for a visually handicapped person of the invention is a leg part of a visually handicapped person.
And when the legs land on the walking surface,
The magnetism detecting means is arranged so as to face the magnetic pole of the magnet.
That it has been made.

According to the present invention, the magnetism detection permitting means uses the magnet by the magnetism detecting means only when the landing detecting means detects that the leg of the visually impaired person has landed. Allow detection of. Therefore, the leg of a visually impaired person lands and the magnetic detection means provided on the leg is positioned substantially perpendicular to the walking surface of the sidewalk, and the magnetic detection device for the magnet embedded in the sidewalk is The magnet can be detected under the condition that the detection sensitivity is optimum. Accordingly, it is possible to prevent erroneous detection of the magnet and accurately detect the magnet.

Further, when the leg of the visually impaired person lands, the weight of the visually impaired person is applied to the sole of the shoe worn by the visually impaired person, so that the pressure applied to the sole increases. Therefore, by using a pressure sensor that detects the pressure applied to the sole of the shoe attached to the leg as the landing detection means, it is possible to confirm that the leg is landing according to the pressure detected by the pressure sensor. Can be detected.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a walking assist device for the visually impaired of the present invention, FIG. 2 is a circuit diagram of the walking assist device shown in FIG. 1, and FIG. 3 is an explanatory view of a usage mode of the walking assist device shown in FIG. is there.

Referring to FIG. 1, a walking assist device 1 for visually impaired persons (hereinafter referred to as walking assist device 1) according to the present embodiment.
Detects the magnet 3 buried in the sidewalk 2 and informs the visually impaired person with a buzzer. The walking assistance device 1 is attached to a leg 4 of a visually impaired person, detects a magnetic flux density of a magnetic field generated by a magnet 3, and outputs a voltage according to the detected magnetic flux density. A foot switch 7 (corresponding to the landing detection means and the pressure sensor of the present invention) provided on the heel portion is provided.

The foot switch 7 is connected to the main body of the walking assistance device 1 by a cable 8 and, as shown in FIG. 1 (b),
It is configured by covering a cap 12 made of conductive rubber so as to straddle two exposed wirings 10 and 11 in a comb shape which are opposed to each other with a space provided on the substrate. Then, when the leg 4 of the visually impaired person lands, when the pressure above the predetermined pressure is applied to the cap 12 by the pedaling force applied from above the cap 12, the central portion of the cap 12 dents and presses against the substrate.
As a result, the exposed wirings 10 and 11 are electrically connected to each other via the conductive rubber cap 12.

Next, the structure and operation of the walking assist device 1 will be described with reference to FIG. Main body 20 of walking assist device 1
Is connected to the magnetic sensor 5 via the connector 21 and is connected to the foot switch 7 via the connector 22.

As described above, the magnetic sensor 5 outputs a voltage according to the magnitude of the detected magnetic flux density, but the magnet is embedded with the N pole facing the walking surface (the state shown in FIG. 1A). The polarity of the output voltage is reversed between when the magnetic field is detected and when the magnet embedded with the S pole facing the walking surface is detected. Therefore, the main body 20 changes the ringing time of the buzzer between when the magnet embedded with the N pole facing the ground surface is detected and when the magnet embedded with the S pole facing the ground surface is detected. Is configured.

In the figure, the operational amplifiers 30 and 31 and the comparator 32 have a structure for detecting a magnet embedded with the N pole facing the walking surface, and the positive detection voltage output from the magnetic sensor 5 is It is operationally amplified by the operational amplifier 30, non-inverting amplified by the operational amplifier 31, and input to the positive input terminal of the comparator 32. The N pole reference voltage V _N generated by the N pole detection reference voltage circuit 3 is input to the negative input terminal of the comparator 32.

Since the output of the comparator 32 is pulled up to the power supply voltage potential, the detection voltage of the magnetic sensor 5 becomes a predetermined N pole detection level or higher, and the output voltage of the operational amplifier 31 becomes the N pole reference voltage V _N. When the above is reached, the logic high level voltage is output from the comparator 32 to one end of the AND element 34.

Here, at the other end of the AND circuit 34, NO
ON / OFF of the foot switch 7 via the T element 35
A logic high level / logic low level voltage is output accordingly. Therefore, the foot switch 7 is O
Only in the N state, that is, when the visually impaired person is in the state of landing the leg on which the walking assist device 1 is attached,
The output of the comparator 32 is the monostable multivibrator 3
6 is input.

Therefore, when the leg of the visually impaired person is not landed, the inclination θ of the magnetic sensor 5 with respect to the magnet 3 is small, and the sensitivity S of the magnetic sensor 5 is low, as shown in FIG. 3C, The detection result of the magnetic sensor 5 is not reflected in the end-stable multivibrator 36, and the detection of the magnet 3 is prohibited.

Then, as shown in FIG. 3B, the leg of the visually impaired person lands, the inclination θ of the magnetic sensor 5 with respect to the magnet 3 becomes approximately 90 degrees, and the sensitivity S of the magnetic sensor 5 is the best. Only when a certain state is reached, the detection result of the magnetic sensor 5 is reflected in the input of the monostable multivibrator 36, and the detection of the magnet 3 is permitted (the AND element 35 corresponds to the magnetic detection permission means of the present invention. ). As a result, it is possible to prevent the magnet 3 from being detected while the sensitivity of the magnetic sensor 5 is low, and prevent the magnet 3 from being erroneously detected, so that the magnet 3 can be accurately detected.

Then, the monostable multivibrator 36
When the input voltage to the A terminal is switched from the logic low level to the logic high level, the transistor 38 outputs a pulse signal having a time width (hereinafter, referred to as a first time) determined according to the values of the resistor 37 and the capacitor 38. , And the buzzer 39 sounds for the first time.

Next, the operational amplifiers 50 and 51 and the comparator 52 have a structure for detecting a magnet embedded with the S pole facing the walking surface, and the N pole described above is embedded facing the walking surface. As in the case of detecting a magnet, the negative detection voltage output from the magnetic sensor 5 is operationally amplified by the operational amplifier 50 (at this time, the polarity of the detection voltage is inverted) and non-inverted by the operational amplifier 51. It is input to the positive input terminal of the comparator 52. To the negative input terminal of the comparator 52, the S pole reference voltage V _S generated by the S pole detection reference voltage circuit 53 is input.

Then, like the comparator 32, the detection voltage of the magnetic sensor 5 becomes equal to or higher than a predetermined S pole detection level,
When the output voltage of the operational amplifier 52 becomes equal to or higher than the S pole reference voltage V _S , the logic high level voltage is output from the comparator 52 to one end of the AND element 54.

At the other end of the AND element 54, AN
ON / OFF of the foot switch 7, similar to the D element 34
A logic high level / logic low level voltage is output accordingly. Therefore, the foot switch 7 is O
Only when the N state is present, the detection of the magnet is permitted. At this time, if the logic high level is output from the comparator 52, the output voltage from the AND element 54 to the monostable multivibrator 55 changes from the logic low level to the logic low level. Switch to high level.

The monostable multivibrator 55 has a time width (hereinafter, referred to as a second time period) determined according to the values of the resistor 56 and the capacitor 57 when the input voltage to the A terminal is switched from the logic low level to the logic high level. Output pulse signal to the base of the transistor 58, which causes the buzzer 40 to ring for the second time.

Then, in this embodiment, by setting the first time and the second time to different times,
When a magnet embedded with the N pole facing the walking surface is detected,
The ringing time of the buzzer 40 is changed depending on when the embedded magnet is detected with the S pole facing the walking surface. As a result, a magnet having the N pole embedded in the walking surface and a magnet having the S pole embedded in the walking surface are combined and embedded in the sidewalk, so that a visually handicapped person can recognize the branch point of the sidewalk. it can.

In the present embodiment, the inputs to the monostable multivibrators 36 and 55 are permitted / prohibited according to ON / OFF of the foot switch 7, respectively.
Although the magnet is detected only when the foot switch 7 is ON, as another configuration, for example, the power supply to the magnetic sensor 5 and the detection circuit is turned ON according to ON / OFF of the foot switch 7. It may be configured to switch between permission and prohibition of magnet detection by turning on / off. With this configuration, the power consumption of the magnetic sensor 5 and the detection circuit can be reduced.

Although the Hall element is used as the magnetic sensor, the walking assist device may be configured by using another type of detecting element (for example, one using a coil).

As the notification means, for example, a vibrator or the like may be used instead of the buzzer.

Although the foot switch is used as the pressure sensor, a pressure detecting element such as a load cell may be used. Further, a proximity sensor may be provided as the landing detection means, and the proximity sensor may detect the distance between the sole and the walking surface to detect that the leg is in the landing state.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a walking assist device for a visually impaired person.

FIG. 2 is a circuit diagram of the walking assist device for the visually impaired shown in FIG.

FIG. 3 is an explanatory diagram of a usage mode of the walking assist device for the visually impaired shown in FIG. 1.

[Explanation of symbols]

1 ... Walking aid device for visually impaired person, 3 ... Magnet, 5 ... Magnetic sensor, 7 ... Foot switch, 8 ... Cable, 20 ... Main body of walking assist device for visually impaired person

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuo Abe, No. 10, 174, No. 1, Nishikagura, Asahikawa City, Hokkaido 7 Hokkaido Prefectural Forest Products Experiment Station (72) Inventor Koji Iriya, Kawagoe City, Saitama Prefecture 2833 Sunpot Co., Ltd. (56 ) References JP-A-8-292627 (JP, A) JP-A-10-113359 (JP, A) JP-A-8-95487 (JP, A) JP-A-58-163365 (JP, A) 52-135086 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G08G 1/005 A61F 9/08 A61H 3/06

Claims (2)

(57) [Claims] 1. A magnetic sensor for detecting a magnet embedded in a sidewalk with a magnetic pole facing a walking surface, which is provided on a leg of a visually handicapped person. When the magnet is detected by the magnetism detecting means. In a walking aid device for visually impaired persons who gives a notification, when landing detection means for detecting that the leg is in a landed state, and when the landing detection means detects that the leg is in a landed state And a magnetic detection permission unit that permits the detection of the magnet by the magnetic detection unit, and is attached to the leg of a visually impaired person, and the leg attaches to the sidewalk.
When grounded, the magnetic detection means pair with the magnetic pole of the magnet.
A walking aid device for the visually impaired, characterized by being configured to face . 2. The walking assist device for a visually handicapped person according to claim 1, wherein a pressure sensor for detecting a pressure applied to the sole of the shoe attached to the leg is used as the landing detecting means.