Infrared radar for people with weak sight

FIELD: instrument engineering.

SUBSTANCE: invention refers to devices used for warning a person with weak sight against approaching an obstacle, and for assessing the distance thereto. Into infrared radar for people with weak sight there additionally introduced is a switch, the first memory register, in-series connected the second memory register, the second digital-to-analogue converter, the second controllable audio frequency generator and the second headphone, and pulse counter is made in the form of reversible pulse counter. Frequency divider output is simultaneously connected to input of T-type flip-flop, control input of reversible pulse counter and control input of switch. True output of T-type flip-flop is connected to input of left-handed infrared source, and inverted output of T-type flip-flop is connected to input of right-handed infrared source. Output of pulse generator is parallel connected to frequency divider input, inverting input of reversible pulse counter to controllable input of linear instrument with charge coupling. Output of limiting amplifier is connected via the switch to control input of the first memory register and control input of the second memory register. Output of reversible pulse counter is connected simultaneously to data inputs of the first and the second memory registers. Output of the first memory register is connected to the first digital-to-analogue converter connected via the first controllable frequency generator to the first headphone.

EFFECT: improving accuracy of determining location of obstacle relative to movement trajectory of a person with weak sight.

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The invention relates to the field of ophthalmology and can be used to alert the person about approaching the obstacle and the distance to it, for example to ensure the safety of movement for people with impaired vision.

The known device to alert the person with impaired vision about approaching any obstacle (wall, fence). The simplest device is the cane of a blind man, which he finds an obstacle located at a distance of an outstretched stick. Much more functional and has a greater range infrared (IR), the locator for the blind [1]containing the IR emitter and the light receiver placed in the enclosure at the disposal of the user. The output signal from the receiver via the amplifier and the rectifier is fed to the input of the controlled oscillator frequency audio. The directional diagram of the IR emitter and radiation receiver is oriented in the direction of obstacles. IR emitter operates in pulsed mode, which is controlled by the pulse generator. The signal at the output of the rectifier will be proportional to the reflectivity of the obstacles and inversely proportional to the fourth power of the desired distance. Therefore, the audio signal reproduced by the head phone will have a tone whose frequency gradually increases the ore close to the obstacle.

The main disadvantage of the known device [1] is a low-precision estimate of the distance to the obstacle, as the frequency of sound vibrations is a function of not only the desired range, but the reflectivity of the obstacle, which in this constantly changing environment cannot be predicted.

It is also known a device in which the above mentioned disadvantage largely eliminated is the infrared locator for people with vision impairments [2]. It contains an IR emitter and receiver of the infrared radiation, which is made of a mosaic in the form of a linear point of solar cells. The range of scatter of solar cells and IR emitter placed on the same line and separated by a baseline distance Century To improve directional properties in front of the IR emitter and line point photoconverters posted by focusing lens. The output of each PV via the amplifier-limiter connected to the corresponding input digital to analogue Converter, an output connected to the input of the control sound generator frequency. The user directs the device in the direction of the alleged obstacles. If obstacles reflected luminous flux falls on one of the panels, resulting in the output of the corresponding amplifier-limiter operates a single logical is CA. When approaching or removing a user from obstacles IR flow will shift the range of solar cells, towards the IR emitter or in the opposite direction and the signal of the logic unit will be generated on one of the other of limiting amplifiers. So the code at the output of the digital to analogue Converter will change. Accordingly, by changing the digital code output digital Converter is a reduction or increase in the frequency of the audio signal at the output of the controlled oscillator sound frequencies corresponding decrease or increase the distance to the obstacle. The accuracy and the measured ranges of the device [2] depend on the size and total number of point of solar cells, components of the line panels. This requires an appropriate number of limiting amplifiers, which leads to excessive structural complexity and high power consumption.

A disadvantage of the known device [2] is the structural complexity of the device, and the dependence of the accuracy on the size and total number of point of solar cells, components of the line panels. For example, if you change the range from one meter to ten meters with a precision of 10 cm is required not less than one hundred point fotop the formers. This requires an appropriate number of limiting amplifiers, which results in unnecessary design complexity and higher power consumption.

It is known a device in which these disadvantages are largely eliminated is the infrared locator for people with impaired vision [3]. It contains an IR emitter and receiver of the infrared radiation, which is a linear charge-coupled device (LPSS). IR emitter and receiver of the infrared radiation is placed on the same line and separated by a baseline distance b To improve directional properties in front of the IR emitter and receiver are placed focusing lens. Output LPSS through the amplifier-limiter connected to the control input of the memory register, the information input connected to the output of the pulse counter, the counting input of which is connected in parallel with the output of the pulse generator, the managing input LPSS and the input of the frequency divider, the output of which is connected to the IR emitter and the input of the reset pulse, the output of the memory register connected to the input of digital to analogue Converter. In the process of reading information from LPSS at the output of the amplifier-limiter will operate signal of the logic unit only at the moment of reading with the light-sensitive cells LPSS, which is reflected from the illuminated with the I radiation IR emitter. As the pulse counter considers the control pulses shift the charge packets in LPSS, i.e. the number of photosensitive cells LESS at the time of occurrence of logical units on the output of the amplifier-limiter in the pulse counter will be fixed maximum number of lit light-sensitive cells LPSS. The signal of the logical unit from the output of the amplifier-limiter is fed to the controlled input of the memory register. This counter is stored into the memory register. Thus, in the memory register permanently stored cell number LPSS lit reflected from obstacles radiation of the infrared emitter. The number of photosensitive cells LESS functionally associated with the distance to the obstacle. Therefore, the sound generator frequency will generate a signal with a frequency proportional to the number recorded in the memory register, and the headset will emit a frequency that is functionally related to the distance to the obstacle.

The disadvantage of the described device is the lack of accuracy of measuring the distance to the obstacle.

This disadvantage is eliminated in the infrared locator for people with impaired vision [4], which can be used as a prototype. The device contains two IR emitter and receiver of the infrared radiation, which is LESS. The IR slocate is and IR radiation are hosted on the same line and separated by a baseline distance B. To improve directional properties in front of the IR emitter and receiver are placed focusing lens. Output LPSS through the flip-flop is connected to the input key, the output of which is connected to the second input of the pulse counter connected to the digital to analog Converter, and a control input connected to the generator shear pulses, the frequency divider and LPSS. The first input pulse counter connected to the output of the frequency divider, the first and second IR emitter. In the process of reading information from LPSS at the output of the amplifier-limiter is a sequence of logical ones and logical zeros. While passing through the flip-flop, the first logical unit sequence will unlock the key, and the second lock him up. During the open state of the key in the counter will be logical zeros. The pulses from the generator output shift pulses through the public key will be supplied to the pulse counter. At arrival at the entrance of the T-flip-flop of the second logical units, which corresponds to the second light spot, T-trigger would move in the opposite position and close the key. As a result, the pulse counter will accumulate the number of pulses corresponding to the number of photosensitive cells LPSS between exposed cells. When removing obstacles to the number of pulses with the corresponding number of light-sensitive cells LPSS, located between the exposed cells will decrease, and if the approximation is increased. D / a Converter converts the digital signal from the counter pulses in analog, which controls the sound generator frequency. Consequently, at the output of the sound generator frequency is reduced or increased frequency of the audio signal. The audio signal is fed to the headset where it is converted to audio frequency, which is perceived by a person with impaired vision.

With the known device [4] it is difficult to determine where it is relative to the path of movement of the person with impaired vision is an obstacle to the left, right or in the middle. This creates a certain inconvenience to the user of the device.

The technical task of the invention is to improve the accuracy of determining the location of the obstacle relative to the trajectory of the person with impaired vision.

The drawing shows a block diagram of the proposed device.

The solution of this problem is that the inputs of the switch, two memory register, the second digital to analog Converter, the second controllable oscillator sound frequency and the second earpiece, and the pulse counter replaced reversive the first pulse counter. Moreover, the device contains two point IR emitter placed on the same line with LPSS and spaced from its center in different directions on the base distance B (figure 1). Output LESS connected to the input of the amplifier-limiter, the output is connected through a switch with memory registers for the left and right channels, respectively, the information input of which is connected to the output of the reversible pulse counter. The counting input of the reversible pulse counter is connected with the control input LPSS, the output of the pulse generator and the input of the frequency divider, connected to the control input of the switch, the control input of the reversible pulse counter and the input of the T flip-flop whose outputs are connected to inputs of the IR emitters. In the process of reading information from LPSS at the output of the amplifier-limiter will operate signal of the logic unit only at the moment of reading with the light-sensitive cells LPSS, which lit reflected from obstacles radiation left or right with the IR emitter. Since the reversible pulse counter considers the control pulses shift the charge packets in LPSS, i.e. the number of photosensitive cells LESS at the time of occurrence of logical units on the output of the amplifier-limiter in the reversible pulse counter will be recorded the number poppy the distribution panel is minimal illuminated photosensitive cell LPSS. The signal of the logical unit from the output of the amplifier-limiter through the switch goes to the controlled input of the memory register left or right channel. This testimony reversible counter pulses correspond respectively to the memory register left or right channel. Thus, in the memory register of the left channel permanently stored cell number LPSS lit reflected from obstacles radiation left IR emitter, and in the memory register right channel permanently stored cell number LPSS lit reflected from obstacles radiation right IR emitter. Therefore, the audio oscillator will generate signals with frequencies proportional to the numbers recorded in the memory registers, and the headphones will radiate frequency, which is functionally connected with the distance to the obstacle.

The device comprises three lens elements 1, 2 and 3, the optical axis of which is oriented in the direction of obstacles. In the rear focal plane of the lens 1 is placed left IR emitter 4 in the back focal plane of lens 3 placed right IR emitter 5, in the rear focal plane of the lens 2 placed LPSS 6. It is designed to convert the light signal into an electrical signal. IR emitters 4 and 5, as well as LPSS 6 is oriented along the same line. IR emitters 4 and 5 spaced apart in different directions about the relative LPSS 6 on the base length B. Output LPSS 6 is connected to the input of the amplifier-limiter 7. The device includes a pulse generator 8, the output of which is connected to the control input LPSS 6, the input of the frequency divider 9 and the counting input of the reversible pulse counter 10. The pulse generator is designed to generate pulses. The output of the frequency divider 9 is connected to the input of the T flip-flop 11, the controlling input of the reversible pulse counter 10 and control input of the switch 12. Direct T-flip-flop 11 is connected with the left IR emitter 4 and the inverted output of the T flip-flop 11 is connected with the right IR emitter 5. The output of the amplifier-limiter 7 is connected with the information input switch 12. Output 1 switch 12 is connected with the control input of the memory register of the left channel 13, and the output 2 of switch 12 is connected with the control input of the memory register right channel 14. The output of the reversible pulse counter 10 is connected simultaneously to the information input of the memory register of the left channel 13 and the memory register right channel 14. The output of the memory register of the left channel 13 is connected to the input of a digital to analogue Converter left channel 15, the output of the memory register right channel 14 connected to the input of d / a Converter right channel 16. Each d / a Converter is designed to convert digital signal to analog. Output the d / a Converter left channel 15 is connected to the control input of the controlled oscillator frequency audio left channel 17, the output of the d / a Converter right channel 16 is connected to the control input of the controlled oscillator frequency audio right channel 18. Each controlled sound generator frequency is designed to generate audio signals with a frequency proportional to the input analog signal. The output of the controlled oscillator frequency audio left channel 17 connected to the input of the headset left channel 19, the output of the controlled oscillator frequency audio right channel 18 is connected to the input of the headphone right channel 20.

When the device is switched on, the pulse generator 8 generates pulses with a frequency f. The pulses from the output of the pulse generator 8 are simultaneously fed to the input of the frequency divider 9, the counting input of the reversible pulse counter 10 and to the input LPSS 6. The frequency divider 9 reduces the pulse frequency f in M times, with M>N, where N is the number of photosensitive cells LPSS 6. When the first pulse at the output of the frequency divider 9 and he includes at the time of its duration through direct T-flip-flop 11, the left IR emitter 4 nulls reversible pulse counter 10 and puts the switch 12 in position 1. When the second pulse at the output of the frequency divider 9 and he includes at the time of its duration through inverted output of the T flip-flop 11 right IR emitter 5, perekluchaet reversible pulse counter 10 to count down and turns the switch 12 in position 2. When the next pulse at the output of the frequency divider 9, the process is repeated. Luminous flux lenses 1 and 3 focuses on the object, the distance of which varies. The radiation power IR emitters 4 and 5 is selected such that the brightness of the light spots on the object dimension substantially exceeds the brightness of the object of measurement caused by other sources of radiation. Reflected from the object luminous flux of the lens 2 focuses on LPSS 6. The output signal LPSS 6 is fed to the input of the amplifier-limiter 7. The threshold gain of the amplifier-limiter 7 is selected so that its output is operated signal of the logic unit only in the case of focusing of light spots from the IR emitters 4 and 5. With proper engineering design of optical elements of the device when the resolving power of each of the lenses 1, 2 and 3 corresponds to a linear resolution LPSS 6 and the size of the light-emitting surface of the IR emitters 4 and 5, the sizes of the light spots projected on LPSS 6, will be comparable to the size of the light-sensitive surface of each photosensitive cell LPSS 6. Therefore, each light spot can get either one, such as i, a photosensitive cell LPSS 6, or simultaneously on two adjacent photosensitive cells LPSS 6. As a result, the output usilitel is-limiter 7, at the moment of reading the i-th photosensitive cell LPSS 6 there is a logical unit, and in the remaining time reading the charge packets LPSS 6 are logical zeros. When approaching or remove a user from the object light spot from the left IR emitter 4 will be displaced by the photosensitive cells LPSS 6 respectively toward the left IR emitter 4 or in the right side of the infrared emitter 5 and the light spot from the right IR emitter 5 will be displaced by the photosensitive cells LPSS 6, respectively, in the right side of the infrared emitter 5 or toward the left IR emitter 4. The signal of the logic unit will be generated either on the photosensitive cell LPSS 6 k>1, or j<i. When enabled, the left IR emitter 4, the outputs of the amplifier-limiter 7 is supplied through the switch 12 to the control input of the memory register of the left channel 13. When you enable the right IR emitter 5, the outputs of the amplifier-limiter 7 is supplied through the switch 12 to the control input of the memory register right channel 14. Therefore, in the memory registers will be written the number of photosensitive cells LPSS 6, which focus light from the IR emitters 4 and 5, and when an object is deleted measuring the number of photosensitive cells is going to be decrease, and when approaching to grow. D / a Converter 15 converts the digital signal from the memory register of the left channel 13 in analog, which controls the frequency of the controlled oscillator frequency audio left channel 17. Consequently, the generator output frequency audio left channel 17 there is a reduction or increase in the frequency of the audio signal. The audio signal is fed into the left earpiece 19 where it is converted to audio frequency. D / a Converter 16 converts the digital signal from the memory register right channel 14 analog, which controls the frequency of the controlled oscillator frequency audio right channel 18. Consequently, at the output of the sound generator frequency right channel 18 there is a reduction or increase in the frequency of the audio signal. The audio signal is fed into the left earpiece 20 where it is converted to audio frequency. People with impaired vision in each channel accepts audio signals. Tone audio frequency it calculates the range to the obstacle and its location on a motion path.

Sources of information

1. IR locator for the blind. Radio, No. 10, 1989, p.84-86.

2. Grinchenko VI, Razin A., Kabakov H. IR locator for people with impaired vision. RF patent №215311, IPC G01S 17/02 issued 05.05.1999.

3. Grinchenko V., Gusev A.V., Dr. Elena Naumenko, VA, Kabakov H. IR locator for people with impaired vision. RF patent №2185640, IPC 7 G01S 17/02, G08G 1/095, A61F 9/08 issued 20.07.2002.

4. Stevanov A.S., Murashkin, S.N., Kabakov H. IR locator for people with impaired vision. RF patent №2298205, IPC 7 G01S 17/02, A61F 9/08, issued on 27 April 2007

Infrared locator for people with impaired vision contains a digital to analog Converter, an output connected to the input of the headset through the sound generator frequency, three focusing lens, the optical axis of which is oriented in the direction of obstacles, and in the rear focal plane of the first and third lenses posted by infrared heaters, and in the rear focal plane of the second lens placed the radiation receiver, made in the form of a linear charge-coupled device, oriented together with infrared emitters along the same basic lines, and the output of the linear charge-coupled device connected to the input of the amplifier-limiter and the input of the linear charge-coupled device connected in parallel with the oscillator output pulses to the frequency divider, wherein the inputs of the switch, the first memory register, connected in series, the second register memory, the second digital to analog Converter, the second managed GE is erator sound frequency and the second earpiece (right), reversible pulse counter, the output of the frequency divider is also connected to the input of the T flip-flop, the control input of the reversible pulse counter and the control input of the switch, direct T-flip-flop connected to the input of the left infrared emitter, the inverted output of the T flip-flop connected to the input of the right infrared emitter, the output of the pulse generator is connected in parallel with the input of the frequency divider, a counter input of reversible counter pulses to the controlled input of the linear charge-coupled device, the output of the amplifier-limiter is connected through a switch with a control input of the first memory register (left channel) and control input of the second memory register (right channel)the output of the reversible counter pulses simultaneously connected to information inputs of the first and second memory registers, the output of the first memory register connected to the first digital to analog Converter connected via a first controlled frequency generator to the first headset (left).