CN110361716B - Human eye protection circuit for optical detection and ranging system - Google Patents
Human eye protection circuit for optical detection and ranging system Download PDFInfo
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- CN110361716B CN110361716B CN201910471138.2A CN201910471138A CN110361716B CN 110361716 B CN110361716 B CN 110361716B CN 201910471138 A CN201910471138 A CN 201910471138A CN 110361716 B CN110361716 B CN 110361716B
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- 238000001514 detection method Methods 0.000 title claims abstract description 49
- 230000003287 optical effect Effects 0.000 title claims abstract description 15
- 238000005070 sampling Methods 0.000 claims abstract description 26
- 238000006243 chemical reaction Methods 0.000 claims description 11
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 4
- 208000031361 Hiccup Diseases 0.000 description 3
- 230000001960 triggered effect Effects 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 2
- 235000004348 Perilla frutescens Nutrition 0.000 description 1
- 244000124853 Perilla frutescens Species 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/484—Transmitters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/4861—Circuits for detection, sampling, integration or read-out
Abstract
The invention discloses a human eye protection circuit for a light detection and ranging system, which comprises: a digital-to-analog converter that converts an input sampling signal, sampled from the optical detection and ranging system, into an output dc level signal; and a comparator which receives the DC level signal and the threshold voltage signal as inputs and outputs a protection signal simultaneously, wherein the protection signal is fed back to the light detection and ranging system and is used for turning off the light detection and ranging system when the pulse intensity of the light detection and ranging system exceeds the human eye bearing capacity; when the direct-current level signal is higher than the threshold voltage signal, the protection signal is at a high level; otherwise, when the DC level signal is lower than the threshold voltage signal, the protection signal is at a low level. The invention has the beneficial effect of automatically closing the problematic laser driving circuit so as to protect human eyes.
Description
Technical Field
The invention belongs to the field of light detection and ranging, and particularly relates to a human eye protection circuit for a light detection and ranging system.
Background
Many applications cannot measure the distance to a target by establishing actual contact with the target, and possible options for non-contact distance measurement include millimeter wave, laser, and ultrasonic. Light detection and ranging (LIDAR) systems attempt to measure the distance to this target using the time required for light to travel between objects, and flash LIDAR systems use pulsed laser and pulse time flight (TOF) algorithms to calculate the target distance. The narrow pulse of the system emitter has a width of several ns to tens of ns, and the peak power is from hundreds of mW to 70W or even more. For the human eye, the accumulated thermal effects of higher peak power lasers irradiating in a continuous mode or broad pulses can cause damage. But is acceptable to the human eye through a pulsing pattern and a lower duty cycle. The pulse laser driving circuit commonly used at present does not consider the damage to human body, which may be caused by the failure or misoperation of the pulse laser.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides the human eye protection circuit which can be used for the light detection and ranging system, and part of embodiments of the invention can avoid the damage to human body caused by the problem of the driving circuit through multiple safety designs, is compatible with the existing sampling circuit, and can not influence the normal operation of the existing driving circuit. The circuit considers both purely analog circuits and solutions with digital circuit control.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
a human eye protection circuit usable with a light detection and ranging system, the human eye protection circuit comprising: a digital-to-analog converter that converts an input sampling signal, sampled from the optical detection and ranging system, into an output dc level signal; and
the comparator receives the direct current level signal and the threshold voltage signal as inputs and outputs a protection signal at the same time, and the protection signal is fed back to the light detection and ranging system and is used for turning off the light detection and ranging system when the pulse intensity of the light detection and ranging system exceeds the human eye bearing capacity; when the direct-current level signal is higher than the threshold voltage signal, the protection signal is at a high level; otherwise, when the DC level signal is lower than the threshold voltage signal, the protection signal is at a low level.
Preferably, the eye protection circuit further includes: the first end of the latch receives the protection signal as an input, the second end of the latch outputs a conversion signal, and the conversion signal is fed back to the light detection and ranging system and is used for turning off the light detection and ranging system when the pulse intensity of the light detection and ranging system exceeds the human eye bearing capacity, and when the protection signal is converted to a high level, the conversion signal is converted to a high level in a following mode.
Preferably, a third terminal of the latch is connected to the second terminal through an inverter, the third terminal receives the inverted switching signal, and when the third terminal is at a low level, the switching signal output by the second terminal is locked.
Preferably, the latch has a fourth terminal for receiving a reset signal.
Preferably, the optical detection and ranging system comprises a laser driving circuit and an arithmetic unit, wherein the arithmetic unit receives the trigger signal and the inverted conversion signal as inputs, and the arithmetic unit carries out logical AND operation on the trigger signal and the inverted conversion signal and outputs the result to the laser driving circuit.
Preferably, the second end of the latch is connected with a single chip microcomputer, the single chip microcomputer is connected with the optical detection and ranging system, and when the conversion signal received by the single chip microcomputer is at a high level, the single chip microcomputer closes the optical detection and ranging system.
Preferably, the sampling signal is sampled from a laser driver circuit in the light detection and ranging system.
Preferably, the sampling signal is sampled from a laser receiving circuit in the light detection and ranging system.
Preferably, the laser receiving circuit is connected with one end of a transimpedance amplifier, and is used for converting a received laser pulse signal into an electric pulse signal, the other end of the transimpedance amplifier is connected with one end of a cascade amplifier, and is used for amplifying the electric pulse model as the sampling signal, and the other end of the cascade amplifier is connected with the digital-to-analog converter, and is used for inputting the sampling signal.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention can automatically close the problematic laser driving circuit so as to protect eyes;
2. according to the invention, different thresholds can be adjusted according to the pulse width so as to be suitable for different occasions needing to limit the pulse width;
3. the circuit is designed through multiple safety to avoid the damage to human body caused by the problem of the driving circuit, is compatible with the existing sampling circuit, can not influence the normal operation of the existing driving circuit, and is considered as a pure analog circuit and a solution when the digital circuit is used for controlling.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a circuit block diagram of Lidar application.
Fig. 2 is a schematic diagram of an embodiment of the present invention.
Fig. 3 is a schematic block diagram of a sampling signal from a laser driving circuit in an embodiment of the present invention.
Fig. 4 is a schematic block diagram of a sampling signal from a laser receiving circuit in an embodiment of the invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, it should be understood that the terms "longitudinal," "transverse," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.
As shown in fig. 1 to 4, the present embodiment provides a human eye protection circuit usable in a light detection and ranging system, the human eye protection circuit including: a digital-to-analog converter 1, the digital-to-analog converter 1 converting an input sampling signal 11 into an output DC level signal 21, the sampling signal 11 being sampled from the optical detection and ranging system; and
the comparator 2 receives the direct current level signal 21 and the threshold voltage signal 22 as inputs, and simultaneously outputs a protection signal 23, wherein the protection signal 23 is fed back to the light detection and ranging system and is used for turning off the light detection and ranging system when the pulse intensity of the light detection and ranging system exceeds the human eye bearing capacity; when the dc level signal 21 is higher than the threshold voltage signal 22, the protection signal 23 is at a high level; conversely, when the dc level signal 21 is lower than the threshold voltage signal 22, the protection signal 23 is low.
The human eye protection circuit further includes: the first end 31 of the latch 3 receives the protection signal 23 as an input, the second end 32 of the latch 3 outputs a switching signal which is fed back to the light detecting and ranging system for switching off the light detecting and ranging system when the pulse intensity of the light detecting and ranging system exceeds the human eye bearing capacity, and the switching signal is switched to a high level following when the protection signal 23 is switched to a high level.
The third terminal 33 of the latch 3 is connected to the second terminal 32 via the inverter 9, the third terminal 33 receives the inverted switching signal, and when the third terminal 33 is low, the switching signal output from the second terminal 32 is locked.
Latch 3 has a fourth terminal 34 for receiving a reset signal.
The optical detection and ranging system includes a laser driving circuit 4 and an arithmetic unit 5, wherein the arithmetic unit 5 receives a trigger signal 51 and a converted signal after inversion as inputs, and the arithmetic unit 5 performs logical AND operation on the trigger signal 51 and the converted signal after inversion and outputs the result to the laser driving circuit 4.
The second end 32 of the latch 3 is connected with a single-chip microcomputer, the single-chip microcomputer is connected with the optical detection and ranging system, and when the conversion signal received by the single-chip microcomputer is at a high level, the single-chip microcomputer closes the optical detection and ranging system.
The sampling signal 11 is sampled from the laser driving circuit 4 in the optical detection and ranging system.
The sampling signal 11 is sampled from the laser receiving circuit 6 in the optical detection and ranging system.
The laser receiving circuit 6 is connected with one end of the transimpedance amplifier 7 and is used for converting a received laser pulse signal into an electric pulse signal, the other end of the transimpedance amplifier 7 is connected with one end of the cascade amplifier 8 and is used for amplifying the electric pulse type as a sampling signal 11, and the other end of the cascade amplifier 8 is connected with the digital-to-analog converter 1 and is used for inputting the sampling signal 11.
TOF is a shorthand for Time of flight and is interpreted as the meaning of Time of flight. The time-of-flight 3D imaging is to continuously transmit light pulses to a target, then receive light returned from the object by a sensor, and obtain the distance of the target by detecting the flight (round trip) time of the light pulses. Because the TOF algorithm must sample the transmit time and receive time of the transmit module in comparison, it is common to sample the switching circuitry of the laser driven circuitry or to collect the emitted pulsed laser light by a detector. The sampled signal will be a periodic signal, corresponding to a PWM (pulse width modulation) wave with an extremely low duty cycle. The PWM wave can be converted into a dc level in a linear relation with the duty cycle by means of a 1-bit dac (digital to analog conversion), which consists of a low-pass filter and a follower amplifier. When the pulse period is constant and the pulse width is changed, the level of the DAC output becomes higher as the pulse width becomes wider. A threshold level can be set for comparison with the level through an analog comparator, and after the level exceeds the threshold value, a turn-off signal is triggered to turn off the laser driving circuit so as to ensure that no pulse harmful to human bodies is emitted. If the sampled signal is not a PWM but a dc signal, a PWM equivalent to a 100% duty cycle will cause the 1-bit dac to output a very high dc level or saturation, which will trigger the off signal as well.
It is additionally considered that sampling the emitted light pulses using a detector requires TIA (transimpedance amplifier) to restore the light pulses to an electrical pulse signal. Because the signal will be small, it will be amplified in the multi-stage amplifying circuit and compared with the 1-bit DAC. The TIA circuit is arranged in a circuit for collecting and emitting laser through the detector, and the invention can use the same TIA to extract sampling signals.
Considering that the laser pulse disappears after the turn-off circuit is triggered, the level of the 1-bit DAC output becomes 0V which is obviously lower than the threshold value, so that the comparator considers that the pulse normally clears the turn-off signal at the moment. Once the circuit is in an abnormal state, it is continuously turned off as if it were hiccup, so the logic circuit is required to maintain the off signal.
The protection circuit needs to sample PWM waves on a Laser trigger and send the PWM waves into a 1-bit DAC. The 1-bit dac consists of a low pass filter and an op-amp, here illustrated using simple RC filtering, and if the PWM period varies, an adjustable low pass filter may be considered. The 1-bit DAC converts PWM into DC level, then the DC level is compared with threshold voltage by a comparator, when the DC level is higher than the threshold voltage, the input pulse is considered abnormal, the comparator outputs high level, and the need of turning off the laser driving circuit is indicated. The hint state needs to be latched to avoid resetting the hint state to trigger the laser driver to turn on again after the driver is turned off. The latching of the high state may be achieved by a D-latch and inverter combination. The output of the Q terminal is selected according to the state of LE: when LE is high, Q will follow D; when LE is ground, Q will latch the state unaffected by the D input. An inverter is added between Q output and LE: when the D input is low, LE will be pulled high keeping Q consistently low; when the D input is high, the output of LE is inverted low, latching the high signal, after which the input at D will no longer affect the output of Q. The lock state is cleared when the external CLR signal is high. At this point we have two mutually opposite levels to indicate that the laser driving circuitry needs to be turned off at this point: the high level can be given to MCU (single chip microcomputer) to trigger protection interrupt; the low level can be used to and the laser drive trigger signal to turn off the laser pulse as shown in the above figure, or can be used to turn off the PMIC (power management chip) of the laser. If latch-up is not required, the D-latch and inverter may not be used, at which point hiccup protection may be triggered. The addition of a delay open circuit can be considered to lengthen the hiccup time, thereby ensuring that the emitted problem laser interval is enlarged and reducing heat accumulation.
The back end of the use of the detector sampling circuit scheme is substantially the same as the direct sampling drive circuit level, the main difference between the two schemes is that the optical signal needs to be restored by TIA (transimpedance amplifier) and a cascode amplifier is required for proper amplification. The amplified signal is still a PWM signal of a fixed period. The signal can be converted to a normal 1-bit dac.
While the foregoing embodiments have been described in detail and with reference to the present invention, it will be apparent to one skilled in the art that modifications and improvements can be made based on the disclosure without departing from the spirit and scope of the invention.
Claims (7)
1. An eye protection circuit for use in a light detection and ranging system, the eye protection circuit comprising:
-a digital-to-analog converter (1), said digital-to-analog converter (1) converting an input sampling signal (11) into an output dc-level signal (21), said sampling signal (11) being sampled from said light detection and ranging system; and
-a comparator (2), said comparator (2) receiving as inputs said dc level signal (21) and a threshold voltage signal (22) while outputting a protection signal (23);
wherein the protection signal (23) is high when the DC level signal (21) is higher than the threshold voltage signal (22); conversely, when the DC level signal (21) is lower than the threshold voltage signal (22), the protection signal (23) is at a low level;
a latch (3), a first end (31) of the latch (3) receiving the protection signal (23) as input, a second end (32) of the latch (3) outputting a switching signal, the switching signal being fed back to the light detection and ranging system for switching off the light detection and ranging system when the light detection and ranging system pulse strength exceeds the human eye tolerance capability, the switching signal being followed by a high level when the protection signal (23) is switched to a high level,
the third end (33) of the latch (3) is connected with the second end (32) through the inverter (9), the third end (33) receives the inverted conversion signal, and when the third end (33) is in a low level, the conversion signal output by the second end (32) is locked.
2. Eye protection circuit for light detection and ranging systems according to claim 1, characterized in that the latch (3) has a fourth terminal (34) for receiving a reset signal.
3. The eye protection circuit according to claim 2, wherein the light detection and ranging system comprises a laser driving circuit (4) and an operator (5), the operator (5) receives a trigger signal (51) and a converted signal after inversion as inputs, and the operator (5) logically and-calculates the trigger signal (51) and the converted signal after inversion and outputs the result to the laser driving circuit (4).
4. A human eye protection circuit applicable to a light detection and ranging system according to any one of claims 2-3, characterized in that the second end (32) of the latch (3) is connected to a single-chip microcomputer, the single-chip microcomputer is connected to the light detection and ranging system, and when the conversion signal received by the single-chip microcomputer is at a high level, the single-chip microcomputer turns off the light detection and ranging system.
5. Eye protection circuit for a light detection and ranging system according to claim 1, characterized in that the sampling signal (11) is sampled from a laser driver circuit (4) in the light detection and ranging system.
6. Eye protection circuit usable in a light detection and ranging system according to claim 1, characterized in that the sampling signal (11) is sampled from a laser receiving circuit (6) in the light detection and ranging system.
7. The eye protection circuit for an optical detection and ranging system according to claim 6, wherein the laser receiving circuit (6) is connected to one end of a transimpedance amplifier (7) for converting a received laser pulse signal into an electrical pulse signal, the other end of the transimpedance amplifier (7) is connected to one end of a cascode amplifier (8) for amplifying the electrical pulse signal as the sampling signal (11), and the other end of the cascode amplifier (8) is connected to the digital-analog converter (1) for inputting the sampling signal (11).
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910471138.2A CN110361716B (en) | 2019-05-31 | 2019-05-31 | Human eye protection circuit for optical detection and ranging system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910471138.2A CN110361716B (en) | 2019-05-31 | 2019-05-31 | Human eye protection circuit for optical detection and ranging system |
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| CN110361716A CN110361716A (en) | 2019-10-22 |
| CN110361716B true CN110361716B (en) | 2023-12-22 |
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| CN110967683B (en) * | 2019-12-12 | 2022-04-01 | 上海禾赛科技有限公司 | Signal receiving and amplifying circuit and laser radar with same |
| CN111337147B (en) * | 2020-03-16 | 2020-12-08 | 东南大学 | Pixel-level laser pulse detection and measurement circuit |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW201237541A (en) * | 2011-03-11 | 2012-09-16 | Alvis Technologies Corp | Eye safety protection system for laser projection device |
| CN108540130A (en) * | 2018-04-10 | 2018-09-14 | 中国科学院微电子研究所 | A kind of dynamic comparer |
| CN108606774A (en) * | 2018-05-16 | 2018-10-02 | 视微影像(河南)科技有限公司 | A kind of automatic safety protective system and method suitable for opticianry scanned imagery device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7079775B2 (en) * | 2001-02-05 | 2006-07-18 | Finisar Corporation | Integrated memory mapped controller circuit for fiber optics transceiver |
| US10585291B2 (en) * | 2017-04-28 | 2020-03-10 | Yonatan Gerlitz | Eye safety system for lasers |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW201237541A (en) * | 2011-03-11 | 2012-09-16 | Alvis Technologies Corp | Eye safety protection system for laser projection device |
| CN108540130A (en) * | 2018-04-10 | 2018-09-14 | 中国科学院微电子研究所 | A kind of dynamic comparer |
| CN108606774A (en) * | 2018-05-16 | 2018-10-02 | 视微影像(河南)科技有限公司 | A kind of automatic safety protective system and method suitable for opticianry scanned imagery device |
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