CN108008399A - A kind of hand-held laser ranging system and its method - Google Patents

Abstract

The invention discloses a kind of hand-held laser ranging system and its method, belong to laser measuring technique field.The hand-held laser ranging system includes a display screen, one transmitter unit, one receiving unit, one processor unit, the display screen is used for the metrical information and/or status information for showing the hand-held laser ranging system, the transmitter unit is used to launch laser, the receiving unit is used to receive reflection laser, the processor unit is used to draw metrical information, it is characterized in that, the hand-held laser ranging system has an ambient light sensor, for environment-identification luminous intensity, the ambient light intensity that the processor unit is identified according to the ambient light sensor adjusts the laser power that the transmitter unit is launched.The hand-held laser ranging system and its method are the Strength Changes based on ambient light, change laser emitting power, so as to improve the outdoor measurement capability of hand-held laser ranging system.

Description

A handheld laser distance measuring device and method thereof

technical field

The invention relates to the technical field of measuring distance by using radio waves, in particular to a handheld laser distance measuring device using laser and a method thereof.

Background technique

Laser Distance Measuring Instrument (Laser Distance Measuring Instrument) is an instrument that uses a laser as a light source to measure the distance of the target. The rangefinder emits a beam of laser light to the target when it is working, and the laser signal reflected by the target is received by the photoelectric receiving device. From the time difference or phase difference from laser emission to reception, calculate the distance value from emission to target. Laser rangefinders are increasingly valued by civil, military and industrial industries in the fields of length, height, distance, speed, and shape. They have been widely used in many fields, such as major industrial and mining enterprises, power petrochemicals, water conservancy, Communication, environment, construction, geology, police, fire protection, blasting, navigation, railway, military, scientific research institutions, agriculture, forestry, real estate, leisure, outdoor sports, etc.

Laser ranging products can be roughly divided into four categories according to the working principle: phase laser range finder, pulse laser range finder, triangulation laser range finder and laser interferometer. Triangulation rangefinders and laser interferometers are generally used for macro-distance measurement and high-precision measurement, so common handheld rangefinders are based on phase type or pulse type, and phase type rangefinders have high precision (submillimeter level) , The measuring range is short (generally within 200 meters), the pulse measurement accuracy is slightly worse (centimeter level), and the measuring range is large (the maximum range can reach the kilometer level).

The phase laser range finder is generally based on the continuous wave measurement method. The laser emits a modulated sine wave signal. After the laser is irradiated to the target, part of the reflected signal is received by the photoelectric conversion device. After conditioning, the range finder processes The unit calculates the distance information based on information such as the frequency and phase difference of the laser signal. Because it uses continuous wave measurement and is limited by relevant laser safety standards, the laser power cannot exceed 1mW, so this type of distance meter is generally used indoors Measure and measure up close.

When the laser range finder, especially the phase range finder, measures outdoors, when the ambient light is strong, the reflected modulation signal will be submerged in the ambient light noise, so it cannot be measured normally.

In view of this, how to design a new hand-held laser distance measuring device to eliminate the above-mentioned defects and deficiencies in the prior art is a problem to be solved urgently by relevant technical personnel in the industry.

Contents of the invention

In order to overcome the technical problems of the hand-held laser range finder in the prior art, the present invention provides a hand-held laser range finder and its method, which can reasonably adjust the laser emission power and change the modulation signal emission intensity according to the change of the ambient light intensity. Reduce the interference of ambient light noise, improve the signal-to-noise ratio of reception, and then improve the outdoor measurement capability of the laser ranging device.

In order to achieve the purpose of the above invention, the present invention discloses a handheld laser distance measuring device, which includes a display screen, a transmitting unit, a receiving unit, and a processor unit, and the display screen is used to display The measurement information and/or status information of the handheld laser distance measuring device, the transmitting unit is used to emit laser light, the receiving unit is used to receive reflected laser light, and the processor unit is used to obtain measurement information, characterized in that , the handheld laser distance measuring device has an ambient light sensor for identifying the intensity of ambient light, and the processor unit adjusts the laser power emitted by the transmitting unit according to the intensity of ambient light identified by the ambient light sensor.

Furthermore, the ambient light sensor is built in the receiving unit.

Furthermore, the ambient light sensor is arranged in a photoelectric module, and the photoelectric module is externally placed on the receiving unit.

Furthermore, the ambient light sensor is a photoelectric sensor, and the handheld laser distance measuring device has at least one photoelectric sensor.

Furthermore, the photosensor is a photodiode, a photoresistor or an avalanche photodiode.

Furthermore, the handheld laser distance measuring device has a reminder unit, the reminder unit is a buzzer or a display icon or a light-emitting diode, which is used to remind when the emitting unit emits high-power laser.

At the same time, in order to achieve the purpose of the above invention, the present invention also discloses a hand-held laser distance measuring method. The ambient light sensor acquires and identifies the ambient light intensity, and the transmitting unit adjusts the emitting laser power according to the ambient light intensity.

Further, the handheld laser ranging method also includes the following steps:

a The distance measuring device starts the measurement, the transmitting unit emits the laser signal, the receiving unit receives the reflected laser signal, and transmits the measurement signal and status signal to the processor unit after processing;

b The processor unit receives the state signal, and judges the current ambient light intensity by analyzing the change of the state signal;

c judging whether the current ambient light intensity exceeds a preset ambient light intensity threshold;

d If the current ambient light intensity does not exceed the preset ambient light intensity threshold, the transmitting unit uses the factory default laser transmitting power for laser emission;

e If the current ambient light intensity exceeds the preset ambient light intensity threshold and is automatically switched to the emission laser power enhancement mode, the laser emission power is automatically adjusted;

f If the current ambient light intensity exceeds the preset ambient light intensity threshold, and it is not automatically switched to the emission laser power enhanced mode, the display will display a message reminding the user to enter the enhanced mode, and the user can choose whether to enable the enhanced mode through the function button.

Further, the handheld laser ranging method also includes the following steps:

a. The distance measuring device starts the measurement, the transmitting unit emits the laser signal, the receiving unit receives the reflected laser signal, the ambient light sensor recognizes the ambient light intensity, and the receiving unit and the ambient light sensor respectively transmit the measurement signal and the status signal to the processor unit;

b The processor unit receives the state signal, and judges the current ambient light intensity by analyzing the change of the state signal;

c judging whether the current ambient light intensity exceeds a preset ambient light intensity threshold;

d If the current ambient light intensity does not exceed the preset ambient light intensity threshold, the transmitting unit uses the factory default laser transmitting power for laser emission;

e If the current ambient light intensity exceeds the preset ambient light intensity threshold and is automatically switched to the emission laser power enhancement mode, the laser emission power is automatically adjusted;

f If the current ambient light intensity exceeds the preset ambient light intensity threshold, and it is not automatically switched to the emission laser power enhancement mode, the display will display information reminding the user to enter the enhancement mode, and the user can choose whether to enable the enhancement mode through the function button.

Furthermore, after the distance measurement is completed in the enhanced mode, the laser signal will automatically return to the normal power mode.

Furthermore, after the ranging is completed in the enhanced mode, when the laser is turned on for the next laser ranging, the laser signal will automatically return to the normal power mode.

Furthermore, there is a linear relationship between the laser power and the ambient light intensity in the enhanced mode.

Compared with the prior art, the technical solution provided by the present invention has the following advantages: First, it can reasonably adjust the laser emission power according to the change of the ambient light intensity, change the emission intensity of the modulated signal, reduce the interference of ambient light noise, and improve the reception efficiency. Signal-to-noise ratio, thereby improving the outdoor measurement capability of the laser distance measuring device; second, it has a strong power reminder. When the laser is of high power or strong power, the user will be reminded through the display and/or buzzer to avoid the laser beam from irradiating the eyes or other items that can be damaged.

Description of drawings

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the accompanying drawings.

Fig. 1 is the structural representation of the hand-held laser ranging device provided by the present invention;

Fig. 2 is a partial circuit schematic diagram of the receiving unit in Fig. 1;

Fig. 3 is a structural schematic diagram of another handheld laser distance measuring device provided by the present invention;

Fig. 4 is a flow chart of the handheld laser ranging method provided by the present invention.

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. However, the present invention should be understood as not limited to such embodiments described below, and the technical idea of the present invention can be implemented in combination with other known technologies or other technologies having the same functions as those known technologies.

In the description of the following specific embodiments, in order to clearly demonstrate the structure and working mode of the present invention, many directional words will be used to describe, but "front", "rear", "left", "right", "outer Words such as ", "inwardly", "outwardly", "inwardly", "axially" and "radially" are to be understood as convenient terms and should not be understood as limiting terms.

The object of the present invention is to provide a hand-held laser ranging device and its method. Through the detection of ambient light, the reminder of ambient light intensity, the control of laser power, and the reminder of laser power, reasonable adjustment of laser emission can be realized according to the change of ambient light intensity. Power, change the emission intensity of the modulated signal, reduce the interference of ambient light noise, improve the signal-to-noise ratio of reception, and then improve the outdoor measurement capability of the laser ranging device.

Specific embodiments of the present invention will be described in detail below in conjunction with accompanying drawings 1-4.

Fig. 1 is a schematic structural diagram of a handheld laser range finder provided by the present invention. As shown in the figure, the handheld laser distance measuring device provided by the present invention includes a display screen 1, a power supply unit 2, a processor unit 3, a button 4, a transmitting unit 5, a receiving unit 6, and a buzzer 7, wherein the display screen 1 uses Used to display measurement results, measurement status, current function information of the rangefinder, status reminder information, etc., such as when a high-power laser is emitted, a warning message is displayed by displaying a specific icon; the buzzer 7 is mainly used for status reminders. When the emitting laser of the ranging device is a high-power laser, that is, the laser enhancement mode, the buzzer 7 buzzes to show a warning, avoiding the laser beam from irradiating the eyes or other objects that may be damaged; the power supply unit 2 is used for distance measuring The instrument provides suitable working power; the processor unit 3 mainly includes a micro control unit (MCU) and its auxiliary circuit, which is the main control part of the system, and it controls and adjusts the emission laser power emitted by the emission unit 5 according to the state signal transmitted by the receiving unit 6 The button 4 is used to provide the user with a way to input information to the processor unit 3; the transmitting unit 5 is used to complete the modulation and transmission of the signal; the receiving unit 6 has a built-in ambient light sensor, and the receiving unit 6 is used to receive reflected laser light and identify The ambient light intensity is processed and the measurement signal and status signal are transmitted to the processor unit 3 .

In addition, those of ordinary skill in the art should know that the reminder unit of the handheld laser distance measuring device used to remind when the emitting unit emits high-power laser can also be a light emitting diode in addition to a buzzer and a specific icon. When the user is in use, the laser is turned on through the button 4, and the emitting unit 5 emits the laser. After aiming the laser point at the target to be measured, the user triggers the measurement of the handheld laser distance measuring device again through the button 4, and the measurement result is displayed on the display screen 1. . After the measurement is completed, if the measurement is completed in the laser enhancement mode, the emission laser will immediately resume the emission laser to the normal power at the end of this measurement, or the emission laser will return to the normal power when the laser is turned on for the next measurement . When the user presses the button to turn on the laser and when the measurement is completed, the buzzer will beep.

In the hand-held laser distance measuring device provided by the present invention, its receiving unit 6 recognizes the ambient light intensity through the internal receiving sensor (the ambient light sensor and the receiving sensor are the same), thereby providing the laser power level for the distance measuring device to select and emit. For reference, and, there is a linear relationship between laser power and ambient light intensity in boost mode. The ambient light sensor is a photoelectric sensor, and the handheld laser distance measuring device may have one or more photoelectric sensors. The photoelectric sensor can be a photodiode, a photoresistor, an avalanche photodiode (APD) and the like. The APD itself is a photoelectric conversion device, which can not only convert the intensity change of the received laser signal into a current change, but also convert the ambient light into a noise current. An independent photodiode or photoresistor is used to determine the level of ambient light intensity. When the ambient light intensity changes, the operating current of the photodiode or photodiode will also change accordingly. The processor unit 3 can also calculate the The current ambient light intensity level.

FIG. 2 is a partial circuit schematic diagram of the receiving unit in FIG. 1 to illustrate how to use the state of the primary transconductance amplified signal of the APD to determine the level of ambient light intensity. As shown in the figure, two resistors, R1 and R2, provide the DC center potential for the AC signal output by the APD to ensure that the AC signal output after transconductance amplification is within the voltage range of 0-VCC; R3 and C2 form a low-pass filter, In this way, the AC signal output by the transconductance can be programmed with a stable DC signal Vs1, which is provided to the processor unit for collection; the transconductance amplified signal is processed by C1 and then used as the initial AC signal for secondary amplification processing, and finally becomes a demodulation signal S1 is provided to the processor unit for collection; Rf is the transconductance feedback resistance, which determines the amplification factor of the transconductance amplifier circuit; the current Iin is the average output current of the APD, and when it flows through the transconductance resistance Rf, a corresponding voltage drop will be generated.

According to the principle of the operational amplifier, it can be concluded that the relationship between the voltage of Vs1 and Iin is as follows:

When the ambient light becomes stronger, the average output current Iin of the APD becomes larger, and Vs1 becomes smaller. Through batch tests, the relationship between ambient light and Vs1 can be calculated, and the current ambient light intensity can be obtained through the change of Vs1 grade.

Fig. 3 is a schematic structural diagram of another handheld laser distance measuring device provided by the present invention. The difference between the handheld laser distance measuring device shown in Figure 3 and the handheld laser distance measuring device shown in Figure 1 is that the ambient light sensor is not built into the receiving unit, but as an independent photoelectric module 11, external on the receiving unit. Other parts are the same, so no more details.

Fig. 4 is a flow chart of the handheld laser ranging method provided by the present invention. As shown in Figure 4, the handheld laser ranging method provided by the present invention includes the following steps:

S01 Start measurement operation

S02 The photoelectric sensor of the receiving unit obtains the ambient light status, and transmits a status signal to the processor unit

The S03 processor unit receives the status signal to determine the intensity level of the ambient light and display it on the display

S04 Determine whether the ambient light intensity exceeds the preset threshold

S05 When the ambient light intensity does not exceed the preset threshold, the handheld laser distance measuring device uses the factory default laser emission power to emit laser light;

S06 When the ambient light intensity exceeds the preset threshold, further judge whether it is to automatically start the enhanced mode to enter the outdoor measurement mode, that is, to increase the emission laser power. Adjust the laser emission power; if the enhanced mode is not automatically activated, the user is reminded that the enhanced mode needs to be turned on for distance measurement, and the user manually selects whether to adopt the enhanced mode through the function button. When the manual setting is to adopt the enhanced mode, it will remind the current mode to be the enhanced mode, and further adjust the laser emission power; when the manual setting is not to adopt the enhanced mode, the handheld laser distance measuring device will use the factory default laser emission power to transmit the laser;

S07 Perform laser distance measurement

S08 After the distance measurement is completed or when the laser is turned on for the next distance measurement, switch to or stay in the normal power mode, that is, the emission laser power returns to the factory default laser emission power

Compared with the prior art, the handheld laser ranging device and its method provided by the present invention have the following advantages: First, it can reasonably adjust the laser emission power according to the change of the ambient light intensity, change the emission intensity of the modulated signal, and reduce the ambient light noise interference, improve the signal-to-noise ratio of reception, and then improve the outdoor measurement capability of the laser ranging device; second, it has a strong power reminder, and when the laser is at high power or high power, it will remind the user through the display screen and/or buzzer , Avoid laser beams shining on eyes or other objects that may be damaged.

Unless otherwise specified, the qualifiers similar to "first" and "second" appearing in this article do not refer to the limitation of time sequence, quantity, or importance, but are only for the purpose of combining one technology in this technical solution A characteristic is distinguished from another technical characteristic. Similarly, the qualifiers similar to "a" appearing in this article do not refer to a limitation on quantity, but describe technical features that have not appeared above. Likewise, modifiers like "about" and "approximately" that appear before numerals in this article generally include the original number, and their specific meanings should be understood in conjunction with the context. Similarly, unless it is a noun modified by a specific quantitative quantifier, it should be deemed to include both the singular form and the plural form in this article. In this technical solution, the singular number of the technical features can also be included. technical characteristics.

What is described in this specification is only preferred specific embodiments of the present invention, and the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the present invention. All technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments according to the concept of the present invention shall fall within the scope of the present invention.

Claims (12)

1. a handheld laser rangefinder, said handheld laser rangefinder includes a display screen, a transmitting unit, a receiver unit, a processor unit, and said display screen is used to display the range of said handheld laser rangefinder Measurement information and/or state information, the transmitting unit is used to emit laser light, the receiving unit is used to receive reflected laser light, and the processor unit is used to obtain measurement information, characterized in that the handheld laser distance measuring device An ambient light sensor is used to identify the intensity of ambient light, and the processor unit adjusts the laser power emitted by the emitting unit according to the intensity of ambient light identified by the ambient light sensor. 2. The handheld laser distance measuring device according to claim 1, wherein the ambient light sensor is built into the receiving unit. 3. The hand-held laser distance measuring device according to claim 1, wherein the ambient light sensor is arranged in a photoelectric module, and the photoelectric module is placed outside the receiving unit. 4. The handheld laser distance measuring device according to claim 1, wherein the ambient light sensor is a photoelectric sensor, and the handheld laser distance measuring device has at least one photoelectric sensor. 5. The hand-held laser distance measuring device according to claim 4, wherein the photoelectric sensor is a photodiode or a photoresistor or an avalanche photodiode. 6. The handheld laser rangefinder as claimed in claim 1, wherein the handheld laser rangefinder has a reminder unit, and the reminder unit is a buzzer or a display icon or a light emitting diode, used Remind when the transmitting unit emits high-power laser. 7. A handheld laser ranging method, characterized in that the ambient light sensor acquires and identifies the ambient light intensity, and the transmitting unit adjusts the emitting laser power according to the ambient light intensity. 8. The handheld laser ranging method as claimed in claim 7, wherein the handheld laser ranging method further comprises the steps of: a The distance measuring device starts the measurement, the transmitting unit emits the laser signal, the receiving unit receives the reflected laser signal, and transmits the measurement signal and status signal to the processor unit after processing; b The processor unit receives the state signal, and judges the current ambient light intensity by analyzing the change of the state signal; c judging whether the current ambient light intensity exceeds a preset ambient light intensity threshold; d If the current ambient light intensity does not exceed the preset ambient light intensity threshold, the transmitting unit uses the factory default laser transmitting power for laser emission; e If the current ambient light intensity exceeds the preset ambient light intensity threshold and is automatically switched to the emission laser power enhancement mode, the laser emission power is automatically adjusted; f If the current ambient light intensity exceeds the preset ambient light intensity threshold, and it is not automatically switched to the emission laser power enhancement mode, the display will display information reminding the user to enter the enhancement mode, and the user can choose whether to enable the enhancement mode through the function button. 9. The handheld laser ranging method as claimed in claim 7, wherein the handheld laser ranging method also comprises the following steps: a. The distance measuring device starts the measurement, the transmitting unit emits the laser signal, the receiving unit receives the reflected laser signal, the ambient light sensor recognizes the ambient light intensity, and the receiving unit and the ambient light sensor respectively transmit the measurement signal and the status signal to the processor unit; b The processor unit receives the state signal, and judges the current ambient light intensity by analyzing the change of the state signal; c judging whether the current ambient light intensity exceeds a preset ambient light intensity threshold; d If the current ambient light intensity does not exceed the preset ambient light intensity threshold, the transmitting unit uses the factory default laser transmitting power for laser emission; e If the current ambient light intensity exceeds the preset ambient light intensity threshold and is automatically switched to the emission laser power enhancement mode, the laser emission power is automatically adjusted; f If the current ambient light intensity exceeds the preset ambient light intensity threshold, and it is not automatically switched to the emission laser power enhancement mode, the display will display information reminding the user to enter the enhancement mode, and the user can choose whether to enable the enhancement mode through the function button. 10. The handheld laser ranging method according to claim 8 or 9, characterized in that, after the ranging is completed in the enhanced mode, the laser power automatically returns to the normal power mode. 11. The hand-held laser ranging method according to claim 8 or 9, wherein after the ranging is completed in the enhanced mode, when the laser is turned on for the next laser ranging, the laser signal automatically returns to the normal power mode. 12. The handheld laser ranging method according to claim 7, characterized in that there is a linear relationship between the laser power and the ambient light intensity in the enhanced mode.