JPS6355347B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a walking aid device for blind people using an ultrasonic radar system.

2. Description of the Related Art Walking aid devices for blind people are used that use ultrasonic radar to estimate the distance to an obstacle in front.

An object of the present invention is to provide a walking aid device for a blind person as described above, which divides the space in front according to the distance from the blind person and displays a frequency corresponding to the space;
It is an object of the present invention to provide a walking aid device for a blind person that allows the user to continuously know changes in position within the space.

In order to achieve the above object, the walking aid device for blind persons according to the present invention comprises a transmitting means for emitting ultrasound waves forward for a short time when the device is activated or reset, and a means for receiving reflected waves of the ultrasound waves. A reference distance clock generator that generates clock pulses corresponding to divided areas of the front space from the time the device starts operating, in a walking aid device for blind people using an ultrasonic radar system consisting of a wave receiving device that generates a received output. a monostable multivibrator that receives the received output and is operated for a certain period of time, resets the device after the operation is completed, and activates the ultrasonic wave transmitting means; It has a counter that counts clock pulses, a distance decoder that receives the output of the counter and decodes the divided area, and an oscillator with an oscillation frequency corresponding to the divided area, and has a frequency specified by the monostable multivibrator. A tone generator that operates an oscillator corresponding to the area decoded by the decoder output for a certain period of time, and an ear speaker that reproduces the output of the tone generator. It is configured to recognize the location of objects.

Hereinafter, the apparatus according to the present invention will be explained in more detail with reference to the drawings and the like.

Fig. 1 is a circuit diagram showing an embodiment of the walking aid device for blind people according to the present invention, Fig. 2 is a waveform diagram for explaining the operation of the circuit of the embodiment, and Fig. 3 shows continuous distance recognition. FIG. 3 is a waveform diagram for explaining the reason why this is possible.

The reference distance clock generator 1 generates the clock shown in FIG. 2a. The first pulse is set as (0), and clocks are generated in sequence as (1), (2), and (3). This clock is connected to a counter 3 via a gate 2. The output of the counter 3 is constantly decoded by a distance decoder 4. The ultrasonic generation circuit 6 is operated in synchronization with the generation of the clock (0), the ultrasonic signal is amplified by the power amplifier 7, and the ultrasonic wave is emitted to the front space by the ultrasonic transmitter 8. . The reception inhibiting gate 5 outputs a signal to the gate 11 for inhibiting reception during the operation period of the transmitter 8 and the next clock period. The output of inhibit gate 5 is shown in FIG. 2c. The reflected wave from the obstacle ahead is detected by the ultrasonic receiver 9 and input to the amplifier 10. The signal is input to the first monostable multivibrator OSM 12 via the gate 11 described above.
Assume that a reflected wave is detected at the time when a clock pulse (5) is being generated as shown in FIG. 2d. this
OSM 12 determines the sound display period. This OSM1
2 closes the gate 2 and the contents of the counter 3 are decoded by the decoder 4. The output of the decoder 4 is connected to a distance gate 14. The distance gate 14 has a number of gates G ₁ , G _{2 . .} . connected to the output of the decoder 4 and the output of the OSM 12.
I have a _G6 . The output of each gate is provided by oscillators F ₁ and F ₂ each given its own oscillation frequency.
. . . is connected to the corresponding oscillator of the oscillator group 15 consisting of _F6 . The equidistant gate 14 and the oscillator group 15 constitute a tone generator, which causes the oscillator selected by the decoded output of the decoder 4 to oscillate for a period specified by the OSM 12. In this example, the output of the decoder 4 appears at the terminal indicated by "5", which opens _G4 and causes _F4 to oscillate for a certain period of time. This oscillation output g is the amplifier 1
6 is amplified and connected to the ear speaker of the headphone 17, and transmits the oscillation frequency of the oscillator _F4 to the blind person. When there is an obstacle in the closest area, the oscillator F ₁ is operated, and when the obstacle is in the farthest area, the oscillator F ₆ is operated. OSM1 mentioned above
When the display period 2 ends, the counter 3 is reset, the gate 2 is opened, the counter 3 starts counting, and ultrasonic waves are sent forward.

As explained above, according to the present invention, different frequencies can be presented to a blind person depending on which space of the divided space in front of the vehicle has an obstacle.

Figure 3 shows the angular frequency w (angular frequency at any oscillation angle)
FIG. 2 is a waveform diagram showing that sound is presented at a repetitive angular frequency p. This repetition angular frequency p changes depending on which part of the area the obstacle is located even within the same area where w does not change. Assuming that the amplitude of the burst is E ₀ , the waveform shown in FIG. 3 is given by the following equation.

Note that the repetition angular frequency p is given by 2π/(period from the start of ultrasonic wave transmission to reception of reflected waves + operation period of the monostable multivibrator). The period from the start of ultrasonic wave transmission to the reception of reflected waves is longer in the same area, closer to each other. Of course, the area closer to the device is higher.

E=2E ₀ [1/2sin wt+1/π{cos(w-p)t-
cos(w+p)t}+1/3π{cos(w-3p)t -cos(w+3p)t}+1/5π{cos(w-5p)t
−cos(w+5p)t}+... In other words, it can be understood that the waveform shown in FIG. 3 consists of a wave measurement band whose center frequency is w and which deviates from it to only odd multiples of p. The amplitude of the wave measurement band decreases in proportion to 1/(2n-1). That is, p changes depending on the position of the obstacle, and the frequency spectrum changes as p changes. A blind person can sense changes in this frequency spectrum to determine where obstacles are within the same area.

As explained in detail above, according to the present invention, the space in front is divided according to the distance, and the frequency corresponding to the divided area is displayed.The position of an obstacle within the same area is also detected based on the change in the spectrum. You can make it known. This allows blind people to continuously sense approximate positions and changes in distance within that area, making it possible to continuously perceive the space in front of them at multiple frequencies without interruption.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the walking aid device for blind persons according to the present invention, and FIG. 2 is a waveform diagram for explaining the operation. FIG. 3 illustrates w and p in waveforms. 1... Reference distance clock generator, 2... Gate, 3... Counter, 4... Distance decoder, 5...
...Reception prohibition gate, 6...Ultrasonic transmission wave generation circuit,
7...Power amplifier, 8...Ultrasonic transmitter, 9...
Ultrasonic receiver, 10... Amplifier, 11... Gate, 12... One shot multivibrator (OSM), 13... One shot multivibrator (OSM), 14... Distance gate, 15... Oscillator group, 16...Amplifier, 17...Headphone.

Claims (1)

[Claims] 1 Using an ultrasonic radar system consisting of a transmitter that emits ultrasonic waves forward for a short time when the device is started or reset, and a receiver that receives reflected waves of the ultrasonic waves and generates a received output. A walking aid device for blind persons includes a reference distance clock generator that generates clock pulses corresponding to divided regions of the space in front of the device from the time when the device starts operating, and a reference distance clock generator that receives the received output and is operated for a certain period of time and after the operation is completed. a monostable multivibrator for resetting the ultrasonic waves and starting the ultrasonic wave transmitting means; a counter for counting the clock pulses connected via a gate from the point of ultrasonic emission; a distance decoder for decoding the area decoded, and an oscillator with an oscillation frequency corresponding to the divided area, and operates the oscillator corresponding to the area decoded by the output of the decoder for a certain period specified by the monostable multivibrator. A walking aid device for a blind person comprising a tone generator that generates a tone generator, and an ear speaker that reproduces the output of the tone generator, and is configured to recognize the position of an obstacle in front by changing the reproduced burst frequency and burst interval.