Ultraviolet wide-area ranging system and ranging method

Abstract

The invention provides an ultraviolet wide-area ranging system which can be applied to the technical field of photoelectric information. The ultraviolet wide-area ranging system comprises a driving module used for generating a driving signal; the signal sending module is used for converting the driving signal into a first ultraviolet laser signal and then sending the first ultraviolet laser signal to a to-be-measured object, and the first ultraviolet laser signal is in a cone shape; the signal receiving module is used for receiving the second ultraviolet laser signal reflected by the object to be measured; and the signal processing module is used for calculating a detection distance according to time data of start time measurement and stop time measurement of laser emission. According to the ultraviolet wide-area ranging system provided by the invention, the distance of the to-be-measured object can be measured when the laser roughly faces the to-be-measured object.

Description

Technical Field

[0001] The present disclosure relates to the field of optoelectronic information technology, and more specifically to an ultraviolet wide-area ranging system and a ranging method. Background Art

[0002] Distance measurement technology has a long history of development and is widely used in aerospace, aviation, geological exploration, unmanned driving, drones, etc. With the continuous development of science and technology and manufacturing processes, the demand for distance measurement technology in practical applications has become increasingly greater, and different requirements have been put forward for measurement accuracy, measurement time, and environment.

[0003] Existing distance measurement methods include: laser distance measurement, ultrasonic distance measurement and infrared distance measurement. During the distance measurement process, the external distance measurement sensor has low distance measurement accuracy and is easily affected by environmental interference, especially in daylight conditions and when there is severe sea clutter, which may result in the inability to measure distance. Ultrasonic distance measurement is also easily affected by interference, resulting in inaccurate distance measurement data. In the existing ultraviolet laser distance measurement system, accurate distance measurement can only be performed after the laser is aimed at the object. When the device cannot accurately aim at the object or the exact position of the object is unknown, distance measurement cannot be achieved. Summary of the invention

[0004] In view of the above problems, the present disclosure provides an ultraviolet wide-area ranging system and a ranging method.

[0005] According to a first aspect of the present disclosure, there is provided an ultraviolet wide-area ranging system, comprising: a driving module for generating a driving signal; a signal sending module for converting the driving signal into a first ultraviolet laser signal and then sending the signal to an object to be measured, and generating a laser excitation signal when the first ultraviolet laser signal is excited, wherein the first ultraviolet laser signal has a cone shape; a signal receiving module for receiving a second ultraviolet laser signal after being reflected by the object to be measured, and converting the second ultraviolet laser signal into a laser receiving signal; a signal processing module for starting time measurement under the triggering of the laser excitation signal, and stopping time measurement under the triggering of the laser receiving signal, and calculating the detection distance according to the time data of starting time measurement and stopping time measurement.

[0006] According to an embodiment of the present disclosure, in the first ultraviolet laser signal of the cone, the signal intensity gradually decreases from the central axis of the cone to the surface of the cone.

[0007] According to an embodiment of the present disclosure, when the first ultraviolet laser signal is sent to the object to be measured, the object to be measured is not located on the central axis of the cone.

[0008] According to an embodiment of the present disclosure, the signal sending module includes: a circuit system for modulating a driving signal; a narrow pulse width ultraviolet laser for converting the modulated driving signal into a first ultraviolet laser signal; and an optical emission unit for sending the first ultraviolet laser signal to the object to be measured after optimizing the optical path.

[0009] According to an embodiment of the present disclosure, the modulation mode of the circuit system is any one of binary amplitude keying, quadrature amplitude modulation and digital pulse interval modulation.

[0010] According to an embodiment of the present disclosure, the signal receiving module includes: an optical receiving unit, used to receive the second ultraviolet laser signal after being reflected by the object to be measured, and to shape, converge and filter the second ultraviolet laser signal to obtain a third ultraviolet laser signal; a photoelectric detector, used to convert the third ultraviolet laser signal into a first electrical signal; and a cross-group amplification unit, used to amplify the first electrical signal into a laser receiving signal.

[0011] According to an embodiment of the present disclosure, the optical receiving module unit includes: a converging lens for shaping and converging the second ultraviolet laser signal; and a filter for filtering noise light in a non-ultraviolet band in the shaped and converged second ultraviolet laser signal.

[0012] According to an embodiment of the present disclosure, the cross-group amplification unit includes multiple cross-group amplifiers, and the first electrical signal is amplified by the first cross-group amplifier and multiple cross-group amplifiers through multi-stage resistor-capacitor coupling to form a laser receiving signal.

[0013] According to an embodiment of the present disclosure, the wavelength of the first ultraviolet laser signal is 266 nm, the repetition frequency is 1 kHz, the average power is 12 mw, and the pulse width is 1500 ps.

[0014] The second aspect of the present disclosure provides a method for measuring distance using the above-mentioned ultraviolet wide-area ranging system, comprising: generating a driving signal; converting the driving signal into a first ultraviolet laser signal and then sending it to an object to be measured, wherein the first ultraviolet laser signal is in the shape of a cone; generating a laser excitation signal when the first ultraviolet laser signal is excited, and the ultraviolet wide-area ranging system starts time measurement under the triggering of the laser excitation signal; receiving a second ultraviolet laser signal reflected by the object to be measured; converting the second ultraviolet laser signal into a laser receiving signal, and the ultraviolet wide-area ranging system stops time measurement under the triggering of the laser receiving signal; and calculating the detection distance according to the time data of the start time measurement and the stop time measurement.

[0015] According to the embodiments of the present disclosure, an ultraviolet wide-area ranging system and ranging method provided by the present disclosure have at least one of the following beneficial effects:

[0016] (1) When the precise position of the object to be measured is unknown and only the approximate position of the object to be measured is known, or when the angle and position of the device are limited and the laser cannot be accurately aimed at the object to be measured, the distance measurement of the object to be measured can be performed to achieve distance measurement over a wide area.

[0017] (2) The overall circuit is simple, efficient, small in size, and has low static power consumption, which is convenient for PCB board integration and has good performance stability and heat dissipation performance.

[0018] (3) Ultraviolet laser is used for distance measurement, which can be used for solar-blind distance measurement, and is not affected by light noise or sunlight. It can be used for distance measurement in environments with strong sunlight. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0020] Figure 1 The structural block diagram of the ultraviolet wide-area ranging system provided by the embodiment of the present disclosure is schematically shown;

[0021] Figure 2 The circuit diagram of the STM32F407ZGT6 single-chip computer according to an embodiment of the present disclosure is schematically shown;

[0022] Figure 3 A circuit diagram of a cross-group amplification unit according to an embodiment of the present disclosure is schematically shown;

[0023] Figure 4 A TDC chip diagram according to an embodiment of the present disclosure is schematically shown;

[0024] Figure 5 A flow chart of a distance measurement method according to an embodiment of the present disclosure is schematically shown;

[0025] Figure 6 A diagram schematically shows a first ultraviolet signal working mode of the ultraviolet wide-area system according to an embodiment of the present disclosure; and

[0026] Figure 7 Another working mode diagram of the first ultraviolet signal of the ultraviolet wide-area system according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0028] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0029] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0030] Figure 1 The structural block diagram of the ultraviolet wide-area ranging system provided by the embodiment of the present disclosure is schematically shown;

[0031] Reference Figure 1 The ultraviolet wide-area ranging system 100 may include, for example: a driving module 110 , a signal sending module 120 , a signal receiving module 130 and a signal processing module 140 .

[0032] The driving module is used to generate a driving signal.

[0033] A signal sending module, used for converting the driving signal into a first ultraviolet laser signal and sending the signal to the object to be measured, and generating a laser excitation signal when the first ultraviolet laser signal is excited, wherein the shape of the first ultraviolet laser signal is a cone;

[0034] A signal receiving module, used for receiving the second ultraviolet laser signal reflected by the object to be measured, and converting the second ultraviolet laser signal into a laser receiving signal;

[0035] The signal processing module is used to start time measurement under the triggering of the laser excitation signal, stop time measurement under the triggering of the laser receiving signal, and calculate the detection distance according to the time data of starting time measurement and stopping time measurement.

[0036] In other embodiments, the driver also has a timing function, and can send a driving signal at a predetermined time to measure the distance of the object to be measured in real time.

[0037] In other embodiments, the ultraviolet wide-area ranging system may also include: Figure 1 The display module 150 shown in the figure can display the distance from the object to be measured to the laser emitter in real time according to the data of the driving module and the signal processing module.

[0038] According to the embodiment of the present disclosure, the driving module and the signal processing module are combined and implemented in the STM32F407ZGT6 single chip microcomputer.

[0039] Figure 2 The circuit diagram of the STM32F407ZGT6 single-chip microcomputer according to an embodiment of the present disclosure is schematically shown.

[0040] like Figure 2 As shown, the trigger signal (i.e., the driving signal) given by the START-TRIGER pin of the STM32F407ZGT6 microcontroller is given to the level conversion module TXU0204 module, which converts the driving signal into TTL standard conversion, and then transmits the converted driving signal to the SIG pin of the narrow pulse width ultraviolet laser. The narrow pulse width ultraviolet laser excites the first ultraviolet laser signal under the triggering of the driving signal.

[0041] According to an embodiment of the present disclosure, the signal sending module may include, for example, a circuit system, a narrow pulse width ultraviolet laser, and an optical emission unit.

[0042] The circuit system is used for modulating the driving signal, and the modulation mode of the circuit system is any one of binary amplitude keying, orthogonal amplitude modulation and digital pulse interval modulation.

[0043] A narrow pulse width ultraviolet laser is used to convert the modulated driving signal into a first ultraviolet laser signal; according to an embodiment of the present disclosure, the narrow pulse width laser module has a wavelength of 266nm, a repetition frequency of 1kHz, an average power of 12mW, and a pulse width of 1500ps.

[0044] The optical transmitting unit is used to send the first ultraviolet laser signal to the object to be measured after optimizing the optical path.

[0045] According to an embodiment of the present disclosure, the signal receiving module may include, for example: an optical receiving unit, a photodetector, and a cross-group amplification unit.

[0046] The optical receiving unit is used to receive the second ultraviolet laser signal after being reflected by the object to be measured, and to shape, converge and filter the second ultraviolet laser signal to obtain a third ultraviolet laser signal. Specifically, the optical receiving unit may include, for example, a converging lens and a filter; the converging lens is used to shape and converge the second ultraviolet laser signal; the filter is used to filter the noise light in the non-ultraviolet band in the second ultraviolet laser signal after shaping and convergence, and the passband of the filter is preferably 260-275nm.

[0047] The photoelectric detector is used to convert the third ultraviolet laser signal into a first electrical signal through photoelectric conversion.

[0048] The cross-group amplification unit is used to amplify the first electrical signal into a laser receiving signal. The cross-group amplification unit includes multiple cross-group amplifiers. The first electrical signal is amplified by the first cross-group amplifier and multiple cross-group amplifiers through multi-stage resistor-capacitor coupling to form a laser receiving signal.

[0049] Figure 3 The circuit diagram of the cross-group amplification unit according to an embodiment of the present disclosure is schematically shown.

[0050] According to the embodiment of the present disclosure, Figure 3 As shown, the cross-group amplifier unit consists of two cross-group amplifiers and auxiliary circuits. The two cross-group amplifiers adopt two-stage resistor-capacitor coupling amplification. The cross-group amplifier chip selected is LTC6268-10. The gain-bandwidth product of this chip reaches 4GHz, with extremely low input bias current and low input capacitance, so it can meet high gain while having low noise and power consumption.

[0051] Figure 4 A TDC chip diagram according to an embodiment of the present disclosure is schematically shown.

[0052] According to an embodiment of the present disclosure, the signal processing module may include, for example, a TDC chip module, wherein the TDC chip module may be, for example, a TDC-GP22 chip.

[0053] It should be noted that any multiple modules among the above-mentioned driving module, signal sending module, signal receiving module and signal processing module can be combined into one module for implementation, or any one of the modules can be split into multiple modules. Alternatively, at least part of the functions of one or more of these modules can be combined with at least part of the functions of other modules and implemented in one module.

[0054] It should be noted that at least one of the above-mentioned driving module, signal sending module, signal receiving module and signal processing module can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application-specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or by any one of the three implementation methods of software, hardware and firmware or by an appropriate combination of any of them. Alternatively, at least one of the driving module, signal sending module, signal receiving module and signal processing module can be at least partially implemented as a computer program module, and when the computer program module is run, the corresponding function can be executed.

[0055] Based on the above-mentioned ultraviolet wide-area ranging system, the present disclosure provides a ranging method on the other hand, which uses the above-mentioned ultraviolet wide-area ranging system.

[0056] Figure 5 The flowchart of the distance measurement method according to the embodiment of the present disclosure is schematically shown.

[0057] like Figure 5 As shown, the method includes operations S510 to S560.

[0058] In operation S510 , a driving signal is generated.

[0059] According to the embodiment of the present disclosure, the driving signal is as follows: Figure 2 The START-TRIGER pin of the STM32F407ZGT6 microcontroller is given, and the signal is converted into a TTL signal recognizable by the system through a level conversion module; the level conversion module can be, for example, a TXU0204 module.

[0060] In operation S520, the driving signal is converted into a first ultraviolet laser signal and then sent to the object to be measured to generate a laser excitation signal, and the first ultraviolet laser signal has a cone shape.

[0061] According to the embodiment of the present disclosure, after the SIG pin of the narrow pulse width ultraviolet laser module receives the driving signal, it excites the first ultraviolet laser signal and sends the time signal emitted by the laser to the signal processing module through TRIGGER_OUT.

[0062] In operation S530 , the ultraviolet wide-area ranging system starts time measurement under the triggering of the laser excitation signal.

[0063] According to an embodiment of the present disclosure, the signal processing module may be, for example, a TDC module. TDC module is the abbreviation of a Time-to-Digital Converter module, which is a digital circuit module for measuring time differences. TDC module can convert time differences into digital signals, and is generally used in applications such as measuring ultrashort pulses and time-resolved spectroscopy. TDC module is generally composed of a counter, a clock source, a comparator, and the like. Its working principle is to measure the time difference by comparing the arrival time difference of two signals. When two signals arrive, the counter starts counting until the other signal arrives and stops counting. The count value of the counter is the time difference between the two signals, and this time difference can be output to other circuits for processing via a digital signal.

[0064] After the TDC module receives the time signal when the laser starts to emit, it records the time T1 at that time.

[0065] In operation S540, a second ultraviolet laser signal reflected by the object to be measured is received.

[0066] According to the embodiment of the present disclosure, the second ultraviolet laser signal reflected by the object to be measured can be received by the above-mentioned optical receiving unit, and a clearer ultraviolet laser signal can be obtained by shaping, converging and filtering the second ultraviolet laser signal.

[0067] In operation S550, the second ultraviolet laser signal is converted into a laser receiving signal, and the ultraviolet wide-area ranging system stops time measurement under the triggering of the laser receiving signal.

[0068] According to the embodiment of the present disclosure, the second ultraviolet laser signal is converted into a laser receiving signal, which can be completed by the above-mentioned photodetector and the cross-group amplification unit; according to the embodiment of the present disclosure, the second ultraviolet laser signal is converted into a relatively weak first electrical signal through the photodetector, and the first electrical signal is amplified by the cross-group amplification unit and converted into a clearer laser receiving signal.

[0069] According to an embodiment of the present disclosure, the cross-group amplification unit can be, for example, a two-stage RC coupled amplifier circuit composed of two LTC6268-10 operational amplifier chips. The first electrical signal is amplified into a laser receiving signal by the two-stage RC coupled amplifier circuit and output from the PDSIG pin.

[0070] According to the embodiment of the present disclosure, after the TDC module receives the laser receiving signal output from the PDSIG pin, it triggers to stop measuring time, and the time at this time is recorded as T2.

[0071] In operation S560, a detection distance is calculated based on time data of the start time measurement and the stop time measurement.

[0072] According to the embodiment of the present disclosure, the TDC module transmits T1 and T2 to the single-chip microcomputer system, and the single-chip microcomputer system calculates the measured distance according to T1 and T2.

[0073] The formula for calculating the measured distance is as follows:

[0074]

[0075] Wherein, R is the distance from the object to be measured to the narrow pulse width ultraviolet laser, and c is the speed of light.

[0076] Figure 6 A diagram schematically shows a first ultraviolet signal working mode diagram of an ultraviolet wide-area system according to an embodiment of the present disclosure; Figure 7 Schematically shows another working mode diagram of the first ultraviolet signal of the ultraviolet wide-area system according to an embodiment of the present disclosure;

[0077] like Figure 6As shown, the first ultraviolet laser signal of the embodiment of the present disclosure is a cone. In the first ultraviolet laser signal of the cone, the signal strength gradually decreases from the central axis of the cone to the surface of the cone. The object to be measured can be on the central axis of the cone. At this time, the second ultraviolet laser signal reflected by the object to be measured after receiving the first ultraviolet laser signal is the strongest, so the measured result is the most accurate.

[0078] However, in actual applications, due to limitations in equipment position and angle, or because the exact position of the object to be measured is unknown, the measurement personnel can only know the approximate direction of the object to be measured, and it is impossible to accurately align the central axis of the first ultraviolet laser signal with the object to be measured. Figure 7 As shown, the position of the object to be measured is not on the center axis of the cone.

[0079] At this time, the non-central axis portion of the first ultraviolet laser signal is irradiated onto the object to be measured, and the object to be measured reflects the irradiated portion as a second ultraviolet laser signal and transmits it back to the signal receiving module.

[0080] According to the embodiment of the present disclosure, the wavelength of the first ultraviolet laser signal is 266nm, the repetition frequency is 1kHz, the average power is 12mw, and the pulse width is 1500ps. Under this laser condition, the second ultraviolet laser signal sent back by the object to be measured passes through the TDC module. Due to the filtering, multi-stage amplification and high precision of the TDC module, the second ultraviolet laser can also be well detected, so that the distance from the object to the narrow pulse width ultraviolet laser can be measured.

[0081] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0082] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. An ultraviolet wide-area ranging system, characterized in that: include: A driving module, used for generating a driving signal; A signal sending module, used for converting the driving signal into a first ultraviolet laser signal and sending the signal to the object to be measured, and generating a laser excitation signal when the first ultraviolet laser signal is excited, wherein the first ultraviolet laser signal has a cone shape; A signal receiving module, used for receiving the second ultraviolet laser signal reflected by the object to be measured, and converting the second ultraviolet laser signal into a laser receiving signal; The signal processing module is used to start time measurement under the triggering of the laser excitation signal, stop time measurement under the triggering of the laser receiving signal, and calculate the detection distance according to the time data of starting time measurement and stopping time measurement.

2. The ultraviolet wide-area ranging system according to claim 1, characterized in that: In the first ultraviolet laser signal of the cone, the signal intensity gradually decreases from the central axis of the cone to the surface of the cone.

3. The ultraviolet wide-area ranging system according to claim 1, characterized in that: When the first ultraviolet laser signal is sent to the object to be measured, the object to be measured is not located on the central axis of the cone.

4. The ultraviolet wide-area ranging system according to claim 1, characterized in that: The signal sending module comprises: A circuit system, used for modulating the driving signal; A narrow pulse width ultraviolet laser, used for converting the modulated driving signal into the first ultraviolet laser signal; The optical transmitting unit is used to optimize the optical path of the first ultraviolet laser signal and then send it to the object to be measured.

5. The ultraviolet wide-area ranging system according to claim 4, characterized in that: The modulation mode of the circuit system is any one of binary amplitude keying, orthogonal amplitude modulation and digital pulse interval modulation.

6. The ultraviolet wide-area ranging system according to claim 1, characterized in that: The signal receiving module comprises: an optical receiving unit, used for receiving the second ultraviolet laser signal after being reflected by the object to be measured, and shaping, converging and filtering the second ultraviolet laser signal to obtain a third ultraviolet laser signal; A photoelectric detector, used for converting the third ultraviolet laser signal into a first electrical signal through photoelectric conversion; The cross-group amplification unit is used to amplify the first electrical signal into the laser receiving signal.

7. The ultraviolet wide-area ranging system according to claim 6, characterized in that: The optical receiving module unit comprises: A converging lens, used for shaping and converging the second ultraviolet laser signal; The filter is used to filter the noise light in the non-ultraviolet band in the second ultraviolet laser signal after shaping and focusing.

8. The ultraviolet wide-area ranging system according to claim 6, characterized in that: The cross-group amplification unit includes a plurality of cross-group amplifiers, and the first electrical signal is amplified by the first cross-group amplifier and the plurality of cross-group amplifiers through multi-stage resistor-capacitor coupling to form the laser receiving signal.

9. The ultraviolet wide-area ranging system according to claim 1, characterized in that: The wavelength of the first ultraviolet laser signal is 266 nm, the repetition frequency is 1 kHz, the average power is 12 mw, and the pulse width is 1500 ps.

10. A method for measuring distance using the ultraviolet wide-area distance measurement system according to any one of claims 1 to 9, characterized in that: include: generating a driving signal; Converting the driving signal into a first ultraviolet laser signal and sending it to the object to be measured, wherein the first ultraviolet laser signal has a cone shape; When the first ultraviolet laser signal is excited, a laser excitation signal is generated, and the ultraviolet wide-area ranging system starts time measurement under the triggering of the laser excitation signal; Receiving a second ultraviolet laser signal after being reflected by the object to be measured; converting the second ultraviolet laser signal into a laser receiving signal, and under the triggering of the laser receiving signal, the ultraviolet wide-area ranging system stops time measurement; The detection distance is calculated based on the time data of the start time measurement and the stop time measurement.

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