JP2008275331A - Laser radar device and its ranging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser radar device and its ranging method capable of performing stable measurement in a wide dynamic range without saturation of a signal level, from an object having a high reflectivity and positioned close, up to an object having a low reflectivity and positioned remotely. <P>SOLUTION: This device is equipped with a transmitter 12 for transmitting a transmission wave 1 comprising a pulsed wave or a modulated wave toward an object, a receiver 16 for receiving a reception wave 3 acquired from the transmission wave by being reflected by the object, a distance value computing unit 18 for computing a distance value to the object from a time difference or a phase difference between the transmission wave and the reception wave, a saturation detector 20 for detecting existence of saturation of the reception wave 3, and a distance value synthesizer 22 for synthesizing a proper distance from a plurality of distance values acquired by the distance value computing unit. Transmission intensity or a reception amplification factor is changed dynamically at a prescribed time interval, and a distance value wherein the reception wave is not saturated and the intensity of the reception wave is high is outputted as a measured distance by the distance value synthesizer 22. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laser radar apparatus and a distance measuring method for measuring with a wide dynamic range from an object located near a high reflectance to an object located far away from a low reflectance.

  The laser radar device transmits a laser beam of a pulse wave or a modulated wave toward an object, receives the laser beam reflected by the object, a time difference between the transmission pulse of the pulse wave and the received pulse, or a transmission wave of the modulated wave And a distance value to the object from the phase difference between the received wave and the received wave.

  In such a laser radar device, for example, Patent Document 1 is disclosed as means for adjusting the dynamic range.

The “ranging device” of Patent Document 1 has a dynamic range limit when detecting the amount of incident light, and detects the amount of light of a received light signal for measurement of a target such as a wide range distance and specular reflection. The purpose is to solve problems that cannot be done.
Therefore, in the present invention, as shown in FIG. 9, the light intensity of the received light signal is measured using an optical system 54 for extracting the received light and a plurality of detectors 56. The level of light incident on the plurality of detectors 6 is 1 / 10.1 / 100. ... and optically changed at several levels. Among the plurality of detectors 56, using the peak value of the detector operating within the dynamic range, a correction value is selected from a table of the relationship between the intensity and the correction distance prepared in advance, and the calculation unit 58 performs distance correction. Is.

Japanese Patent Application Laid-Open No. 11-23710, “Rangefinder”

  FIG. 1 is a diagram schematically showing a conventional problem. In this figure, (A) is the relationship between the receiving sensor and the object to be measured, (B) is the received wave intensity when the receiving sensor is adjusted to a short-distance and highly reflective object, and (C) is the long-range and low. Each of the received wave intensities when the receiving sensor is adjusted according to a reflective object is schematically shown.

  In the laser radar device, when the reflectivity of the measurement object is different, the level of the received signal appears. Even when the distances are different, a difference occurs in the signal level.

For example, when the reception sensor is adjusted according to a short distance and highly reflective object, the received wave intensity from the short distance and highly reflective object is appropriate as shown in the upper diagram of FIG. 1B. In addition, the received wave intensity from a low-reflecting object is too small to be detected as shown in the lower diagram of FIG. 1B.
In addition, when the reception sensor is adjusted according to a long distance and low reflection object, the received wave intensity from the long distance and low reflection object is appropriate as shown in the lower diagram of FIG. 1C. As shown in the upper diagram of FIG. 1C, the received wave intensity from a highly reflective object is distorted due to saturation of the signal intensity and does not show an accurate value.

  Therefore, there is a large difference in the received signal level between an object with high reflectivity and a nearby object and an object with low reflectivity and a distant object, and if the former signal level is adjusted appropriately, the latter level However, there is a problem that the distance cannot be measured correctly because the former is electrically saturated when adjusted according to the latter.

  The present invention has been developed to solve the above-described problems. That is, an object of the present invention is to provide a laser radar capable of stably measuring a wide dynamic range without saturation of a signal level from an object located near a high reflectance to an object located far away with a low reflectance. It is to provide an apparatus and a distance measuring method thereof.

According to the present invention, a transmitter for transmitting a transmission wave composed of a pulse wave or a modulated wave toward an object;
A receiver for receiving a received wave reflected by an object from the transmitted wave;
A distance value calculator for calculating the distance value from the time difference or phase difference between the transmitted wave and the received wave to the object;
A saturation detector for detecting the presence or absence of saturation of the received wave;
A distance value synthesizer that synthesizes an appropriate distance from a plurality of distance values obtained by the distance value calculator;
A laser radar characterized by dynamically changing transmission intensity or reception amplification factor at a predetermined time interval, and outputting a distance value in which the received wave is not saturated and the intensity of the received wave is high as a ranging distance An apparatus is provided.

Further, according to the present invention, the transmission intensity or the reception amplification factor is dynamically changed at a predetermined time interval, and a plurality of transmission waves are transmitted toward the object and reflected by the object. Receive
Detecting the presence or absence of saturation of the received wave,
Calculate a plurality of distance values from the time difference or phase difference between the plurality of transmission waves and the reception wave to the object,
A distance measurement method for a laser radar apparatus is provided, wherein a distance value in which the received wave is not saturated and the intensity of the received wave is high is output as a distance measurement distance among the plurality of distance values.

Further, according to the present invention, a first transmitter and a second transmitter that respectively transmit a transmission wave having a first wavelength and a second wavelength, which are a pulse wave or a modulation wave, toward an object;
A first receiver and a second receiver for separately receiving a first wave and a second wave received by the transmission wave reflected by an object;
A first distance value calculator and a second distance value calculator for calculating a distance value from the time difference or phase difference between the transmission wave and the reception wave of the first wavelength and the second wavelength, respectively,
A saturation detector for detecting the presence or absence of saturation of the received wave of the first wavelength or the second wavelength;
A distance value synthesizer that synthesizes an appropriate distance from a plurality of distance values obtained by the first distance value calculator and the second distance value calculator;
The transmission intensity of the first transmitter and the second transmitter, or the reception amplification factor of the first receiver and the second receiver are different,
Among the plurality of distance values, a laser radar device is provided, which outputs a distance value in which the received wave is not saturated and the intensity of the received wave is high as a distance measurement distance.

Further, according to the present invention, the transmission wave of the first wavelength and the second wavelength consisting of a pulse wave or a modulated wave is respectively transmitted toward the object,
The transmission wave receives the first and second wavelength reception waves reflected by the object separately and receives the transmission intensity of the first and second wavelengths, or the reception amplification of the first and second wavelengths. Different rates,
Calculating a distance value from the time difference or phase difference between the transmission wave and the reception wave of the first wavelength and the second wavelength to the object, respectively;
Detecting the presence or absence of saturation of the received wave of the first wavelength or the second wavelength;
A distance measurement method for a laser radar apparatus is provided, wherein a distance value in which the received wave is not saturated and the intensity of the received wave is high is output as a distance measurement distance among the plurality of distance values.

According to the present invention, a transmitter for transmitting a transmission wave composed of a pulse wave or a modulated wave toward an object;
A transmission variable focus device for changing a transmission spread angle of the transmission wave before transmission;
A receiver for receiving a received wave reflected by an object from the transmitted wave;
A variable focus for reception that changes the measurement focus of the received wave before reception;
A distance value calculator for calculating a distance value from the time difference or phase difference between the transmitted wave and the received wave to the object;
A saturation detector for detecting the presence or absence of saturation of the received wave;
A distance value synthesizer that synthesizes an appropriate distance from a plurality of distance values obtained by the distance value calculator;
A laser radar characterized by dynamically changing a transmission divergence angle or a measurement focus at a predetermined time interval, and outputting a distance value in which a received wave is not saturated and the intensity of the received wave is high as a distance measured. An apparatus is provided.

Further, according to the present invention, at a predetermined time interval, a transmission divergence angle or a measurement focus is dynamically changed, a plurality of transmission waves are transmitted toward an object, and a plurality of reception waves reflected by the object are transmitted. Receive
Detecting the presence or absence of saturation of the received wave,
Calculate a plurality of distance values from the time difference or phase difference between the plurality of transmission waves and the reception wave to the object,
A distance measurement method for a laser radar apparatus is provided, wherein a distance value in which the received wave is not saturated and the intensity of the received wave is high is output as a distance measurement distance among the plurality of distance values.

  According to the first apparatus and method of the present invention, the transmission intensity or the reception amplification factor is dynamically changed at predetermined time intervals, the received wave is not saturated, and the distance value with high received wave intensity is obtained. Since it is output as a distance measurement distance, it is possible to stably measure from an object located near the object with high reflectivity to an object located far away with a low reflectivity without saturation of the signal level.

  Further, according to the second apparatus and method of the present invention, the transmission intensity of the first transmitter and the second transmitter or the reception amplification factors of the first receiver and the second receiver are different from each other. Because the distance value of the received wave does not saturate and the received wave intensity is high is output as the distance measurement distance, the object is located far away from the object with high reflectivity. It is possible to stably measure even an object that does not saturate the signal level.

  Further, according to the third apparatus and method of the present invention, the transmission divergence angle or the measurement focus is dynamically changed at a predetermined time interval, and the received wave is not saturated among the plurality of distance values. Since the distance value with high wave intensity is output as the distance measurement, the signal level is stable without saturation from an object with high reflectivity and a nearby object to an object with low reflectivity and a distant object. It can be measured.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 2 is an overall configuration diagram of a laser radar device according to the present invention. In this figure, a laser radar device 10 of the present invention includes a transmitter 12, a scanner device 14, a receiver 16, a distance value calculator 18, and a controller 19.

  The transmitter 12 transmits a transmission wave 1 composed of a pulse wave or a modulated wave toward an object. The transmission wave 1 is preferably a pulsed laser beam, but may be a modulated laser beam. The transmitter 12 can freely control the oscillation timing and pulse period of the pulse wave or the modulation period and phase of the modulation wave by the control signal 5a from the controller 19.

The scanner device 14 transmits the transmission wave 1 toward the object.
In this example, the scanner device 14 is an optical scanner device that reflects the transmission wave 1 and can scan one-dimensionally or two-dimensionally toward a predetermined measurement region. As the optical scanner device, a fine MEMS mirror, a polygon scanner, a galvano scanner, or the like can be used.
The scanning speed of the optical scanner device can be changed in real time by the speed command 6 from the controller 19. Further, the angle information 7 of the optical scanner device is notified to the controller 19.
The scanner device 14 is not essential, and the transmission wave 1 may be transmitted directly from the transmitter 12 toward the object.

  The receiver 16 receives the reception wave 3 in which the transmission wave 1 is reflected by the object. The reception timing 8 of the reception wave 3 is notified to the distance value calculator 18.

  The distance value calculator 18 calculates a distance value 9 from the time difference or phase difference between the transmission wave 1 and the reception wave 3 to the object. The calculated distance value 9 is notified to the controller 19.

The controller 19 controls the transmitter 12, the receiver 16, and the distance value calculator 18, and outputs the control signals 5 a and 5 b and the speed command 6 based on the distance value 9 obtained by the distance value calculator 18. .
Further, the controller 19 generates angle distance information from the scan angle 7 of the optical scanner and the distance value 9 received from the distance value calculator 18, and is illustrated as measurement data 11 (two-dimensional data or three-dimensional data). Output to a non-output device (display device, storage device, control device, etc.).

  FIG. 3 is a diagram showing a first embodiment of a laser radar device according to the present invention. In this figure, the laser radar device of the present invention includes a transmitter 12, a receiver 16, a distance value calculator 18, a saturation detector 20, and a distance value synthesizer 22.

  In this example, the transmitter 12 can variably adjust the intensity of the transmission wave 1 in magnitude (or strength), and the receiver 16 can variably adjust the reception amplification factor of the reception wave 3 in magnitude. Note that only one of the variable functions of the transmission intensity or the reception amplification factor may be used.

The saturation detector 20 detects the presence or absence of saturation of the received wave 3 and inputs the result to the distance value synthesizer 22.
The distance value synthesizer 22 has a function of synthesizing an appropriate distance from a plurality of distance values obtained by the distance value calculator 18, and at a predetermined time interval, the transmission intensity of the transmitter 12 or the reception amplification of the receiver 16. The rate is dynamically changed, and the distance value where the received wave 3 is not saturated and the intensity of the received wave is high is output as a distance measurement distance.

  The saturation detector 20 and the distance value synthesizer 22 are preferably incorporated in the controller 19 described above. However, the present invention is not limited to this, and may be configured as a separate control device.

  FIG. 4 is an overall flowchart of the first ranging method of the laser radar apparatus according to the present invention using the above-described apparatus. In this figure, the distance measuring method of the present invention comprises steps S1 to S9.

In this example, N is an integer of 2 or more, M is an integer of 1 or more, and M <N.
When the number of transmissions is N or less in step S1, a distinction is made between the case where the number of transmissions exceeds M (YES) and the case where it is less than M (NO) in step S2. If it exceeds M (YES), the transmission intensity is set high or the reception amplification factor is large in step S3, and if it is less than M (NO), the transmission intensity is set low or the reception amplification factor is low in step S4.
In step S5, the transmission wave 1 is transmitted toward the object with the set transmission intensity or reception amplification factor, and the reception wave 3 reflected by the object is received.
If the received wave 3 is not received in step S6 and if the received wave 3 is saturated in step S7, the process returns to step S1 because there is no received data or is not accurate.
If there is reception (YES) and it is not saturated, the received data is useful, so the distance value calculated in step S8 is held. In this step, the final distance value may be overwritten with new data, or the maximum value may be selected from a plurality of data.
After repeating the above steps N times, the distance value held in step S9 is determined as the final distance value, and the distance measurement is terminated.

  That is, in this embodiment, when the laser light is transmitted in a state where the transmission intensity or the reception amplification factor is low and the laser light reflected on the measurement object can be received by the receiver, from the transmission / reception time difference to the measurement object Calculate the distance. If the received light signal is not saturated, the calculated distance value is held. After the above is repeated a certain number of times, the processing is similarly repeated a certain number of times in a state where the transmission intensity or the reception gain is high. The last distance value is output as the final distance value.

As described above, the distance measuring method of the present invention dynamically changes the transmission intensity or the reception amplification factor at a predetermined time interval, and transmits a plurality of transmission waves toward the object. Receiving a plurality of reflected waves (S1 to S6);
Detecting the presence or absence of saturation of the received wave (S7);
A plurality of distance values from the time difference or phase difference between the plurality of transmission waves and the reception waves to the target are calculated, and among the plurality of distance values, a distance value in which the reception wave is not saturated and the intensity of the reception wave is high. The distance is output as a distance measurement (S8 to S9).

  According to the apparatus and method of the first embodiment of the present invention described above, the transmission intensity or the reception amplification factor is dynamically changed at predetermined time intervals, the reception wave 3 is not saturated, and the intensity of the reception wave is reduced. Since a high distance value is output as a distance measurement distance, it is possible to stably measure an object located close to a highly reflective object to an object located far away and having a low reflectance without saturation of the signal level.

  FIG. 5 is a diagram showing a second embodiment of the laser radar device according to the present invention. In this figure, the laser radar device of the present invention includes transmitters 12A and 12B, filters 15A and 15B, receivers 16A and 16B, distance value calculators 18A and 18B, a saturation detector 20, and a distance value synthesizer 22.

  The first transmitter 12A and the second transmitter 12B respectively transmit the transmission waves 1A and 1B having the first wavelength a and the second wavelength b, which are pulse waves or modulated waves, toward the object. The first wavelength a and the second wavelength b are different in wavelength, and the filter 15A is selected to pass the first wavelength a, and the filter 15B is selected to pass the second wavelength b.

The first receiver 16A and the second receiver 16B receive the received waves 3A and 3B of the first wavelength a and the second wavelength b, which are reflected by the objects 1A and 1B, separated by the filters 15A and 15B, respectively. To do.
Further, the transmission intensity of the first transmitter 12A and the second transmitter 12B described above or the reception amplification factors of the first receiver 16A and the second receiver 16B are different. For example, in this example, the transmission intensity of the first transmitter 12A or the reception amplification factor of the first receiver 16A is large, and the transmission intensity of the second transmitter 12B or the reception amplification factor of the second receiver 16B is small. Is set.

  The first distance value calculator 18A and the second distance value calculator 18B are distance values from the time difference or phase difference between the transmission waves 1A, 1B and the reception waves 3A, 3B of the first wavelength a and the second wavelength b to the object. Are respectively calculated.

The saturation detector 20 detects the presence or absence of saturation of the received waves 3A and 3B (the received wave 3A in this example) having the first wavelength a or the second wavelength b.
The distance value synthesizer 22 has a function of synthesizing an appropriate distance from the plurality of distance values obtained by the first distance value calculator 18A and the second distance value calculator 18B. A distance value in which 3A and 3B are not saturated and the intensity of the received wave is high is output as a distance measurement distance.

  FIG. 6 is an overall flowchart of the second distance measuring method of the laser radar apparatus according to the present invention using the above-described apparatus. In this figure, the distance measuring method of the present invention comprises steps S11 to S18.

In step S11, wavelength a and wavelength b are transmitted.
If there is reception of wavelength a in step S12 (YES) and no reception of wavelength b in step S13 (NO), the distance value calculated from the transmission / reception interval of wavelength a in step S16 is adopted.
Even if the wavelength b is received (YES) in step S13, if the wavelength a is not saturated (NO) in step S15, the wavelength a is prioritized, and the distance value calculated from the transmission / reception interval of the wavelength a is adopted in step S16. .
If the wavelength a is saturated in step S15 (YES), the distance value calculated from the transmission / reception interval of wavelength b in step S17 is adopted.
If there is no reception of wavelength a in step S12 (NO) and reception of wavelength b in step S14 (YES), the distance value calculated from the transmission / reception interval of wavelength b in step S17 is adopted.
If no wavelength b is received (NO) in step S14, it is determined in step S18 that there is no distance value.
After step S16, step S17, and step S18 described above, the distance measurement is terminated.

In other words, this embodiment includes a combination of transmitters having different wavelengths a and b and filters and receivers that allow only wavelengths a and b to pass therethrough. A distance value calculator is provided for each of the wavelengths a and b, a saturation detector is provided for the wavelength a, and a distance value synthesizer is provided in common for the wavelengths a and b.
The wavelength a is set to a large transmission intensity or reception amplification factor, and the wavelength b is set to a small value, and each transmits laser light. When the laser beam reflected by the measurement object is received only at the wavelength a, the distance to the measurement object calculated from the transmission / reception time difference of the wavelength a is adopted.
When there is reception at both wavelengths a and b and the received signal at wavelength a is not saturated, a distance value using wavelength a having high received intensity and excellent S / N is adopted.
When both the wavelengths a and b are received and the wavelength a is saturated, a measurement error occurs due to the saturation at the wavelength a. Therefore, the distance value by the wavelength b is adopted.
Although it should not occur originally, in the unlikely event that reception occurs only at the wavelength b, the distance value by the wavelength b is adopted.

As described above, the distance measuring method of the present invention transmits the transmission waves 1A and 1B of the first wavelength a and the second wavelength b, which are pulse waves or modulated waves, toward the object, respectively (step S11).
The transmission waves 1A and 1B are received separately from the reception waves 3A and 3B of the first wavelength a and the second wavelength b reflected by the object, and the transmission intensity of the first wavelength a and the second wavelength b, or the first Differentiating the reception amplification factors of the wavelength a and the second wavelength b,
Calculating the distance value from the time difference or phase difference between the transmission waves 1A, 1B and the reception waves 3A, 3B of the first wavelength a and the second wavelength b to the object, respectively;
The presence or absence of saturation of the received wave 3A of the first wavelength a (or the second wavelength) is detected (step S15),
Among the plurality of distance values, a distance value in which the received wave is not saturated and the intensity of the received wave is high is output as a distance measurement distance (S12 to S17).

  According to the apparatus and method of the second embodiment of the present invention described above, the transmission intensities of the first transmitter 12A and the second transmitter 12B or the reception amplification factors of the first receiver 16A and the second receiver 16B are different. Among the multiple distance values, the distance value where the received wave is not saturated and the intensity of the received wave is high is output as the distance measurement distance. Even low and distant objects can be measured stably without signal level saturation.

  FIG. 7 is a diagram of a third embodiment of a laser radar device according to the present invention. In this figure, the laser radar apparatus of the present invention includes a transmitter 12, a transmission variable focus device 13, a receiver 16, a reception variable focus device 17, a distance value calculator 18, a saturation detector 20, and a distance value synthesizer 22. Is provided.

The transmission variable focus unit 13 changes the transmission divergence angle of the transmission wave 1 before transmission, narrows the transmission divergence angle (sets the focal distance to a long distance), and increases the transmission wave density irradiated to the object. Alternatively, the transmission wave density applied to the object can be made sparse by widening the transmission divergence angle (setting the focal length to a short distance).
Further, the receiving variable focus unit 17 changes the measurement focus of the reception wave 3 before reception, and when focusing on a long distance (the focal distance is set to a long distance), the reception wave from a short distance is weakened. When focusing on a short distance (focal length is set to a short distance), received waves from a long distance are weakened.
Other configurations are the same as those of the first embodiment described above.

  FIG. 7 is an overall flow diagram of the third distance measuring method of the laser radar apparatus according to the present invention using the above-described apparatus. In this figure, the distance measuring method of the present invention comprises steps S21 to S29.

In this example, N is an integer of 2 or more, M is an integer of 1 or more, and M <N.
When the number of transmissions is N or less in step S21, a distinction is made between the case where the number of transmissions exceeds M (YES) and the case where it is less than M (NO) in step S22. If it exceeds M (YES), the focal length is set to a long distance in step S23 and the transmission intensity is set to be large or the reception amplification factor is large. If it is less than M (NO), the focal length is set to a short distance in step S24. In addition, the transmission intensity is set low or the reception gain is set low.
In step S25, the transmission wave 1 is transmitted toward the object with the set focal length, transmission intensity, and reception amplification factor, and the reception wave 3 reflected by the object is received.
If the received wave 3 is not received in step S26 and if the received wave 3 is saturated in step S27, the process returns to step S21 because there is no received data or is not accurate.
If there is reception (YES) and it is not saturated, the received data is useful, so the distance value calculated in step S28 is held. In this step, the final distance value may be overwritten with new data, or the maximum value may be selected from a plurality of data.
After repeating the above steps N times, the distance value held in step S29 is determined as the final distance value, and the distance measurement is terminated.

  That is, in this embodiment, the focal length of transmission / reception is dynamically changed at regular intervals, and when focusing on a short distance, the transmission intensity or reception amplification factor is set low, and when focusing on a long distance, transmission is performed. Set strength or reception gain high. When the transmission intensity or reception amplification factor is increased and the object is focused far away, the energy density of the transmitted signal is low because the focus is out of focus even if an object with high reflectivity exists at a short distance. The signal level is kept low. This prevents saturation at short distances and expands the measurement distance range.

As described above, the distance measuring method of the present invention dynamically changes the transmission divergence angle or the measurement focus at a predetermined time interval, and transmits a plurality of transmission waves toward the object. A plurality of reflected reception waves are received (S21 to S26),
Detecting the presence or absence of saturation of the received wave (S27);
A plurality of distance values from the time difference or phase difference between the plurality of transmission waves and the reception waves to the target are calculated, and among the plurality of distance values, a distance value in which the reception wave is not saturated and the intensity of the reception wave is high. The distance is output as a distance measurement (S28 to S29).

  Therefore, according to the apparatus and method of the third embodiment of the present invention, the transmission divergence angle or the measurement focus is dynamically changed at a predetermined time interval, and the received wave is not saturated among a plurality of distance values. In addition, since the distance value with high received wave intensity is output as a distance measurement distance, it is stable without saturation of the signal level, from objects with high reflectivity to nearby objects to objects with low reflectivity and located far away. Can be measured.

  In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention. For example, the laser radar device to which the present invention is applied is not limited to laser light, and single wavelength light such as an LED, millimeter wave, microwave, ultrasonic wave, or the like may be used.

It is a figure which shows the conventional problem typically. 1 is an overall configuration diagram of a laser radar device according to the present invention. 1 is a first embodiment of a laser radar device according to the present invention. It is a whole flowchart of the 1st ranging method of the laser radar apparatus by this invention. It is 2nd Embodiment figure of the laser radar apparatus by this invention. It is a whole flowchart of the 2nd ranging method of the laser radar apparatus by this invention. It is a 3rd embodiment figure of a laser radar device by the present invention. It is a whole flowchart of the 3rd ranging method of the laser radar apparatus by this invention. 10 is a schematic diagram of a “ranging device” in Patent Document 1. FIG.

Explanation of symbols

1, 1A, 1B transmission wave, 3, 3A, 3B reception wave,
5a, 5b control signal, 6 speed command, 7 angle information,
8 Light reception timing, 9 Distance data,
10 Laser radar device, 11 Measurement data,
12, 12A, 12B transmitter,
13 Variable focus device for transmission, 14 Scanner device,
15A, 15B filter, 16, 16A, 16B receiver,
17 Variable focus device for reception,
18, 18A, 18B Distance value calculator, 19 controller,
20 Saturation detector, 22 Distance value synthesizer

Claims (6)

A transmitter for transmitting a transmission wave composed of a pulse wave or a modulation wave toward an object;
A receiver for receiving a received wave reflected by an object from the transmitted wave;
A distance value calculator for calculating the distance value from the time difference or phase difference between the transmitted wave and the received wave to the object;
A saturation detector for detecting the presence or absence of saturation of the received wave;
A distance value synthesizer that synthesizes an appropriate distance from a plurality of distance values obtained by the distance value calculator;
A laser radar characterized by dynamically changing transmission intensity or reception amplification factor at a predetermined time interval, and outputting a distance value in which the received wave is not saturated and the intensity of the received wave is high as a ranging distance apparatus. In a predetermined time interval, the transmission intensity or the reception amplification factor is dynamically changed, and a plurality of transmission waves are transmitted toward the object, and a plurality of reception waves reflected by the object are received,
Detecting the presence or absence of saturation of the received wave,
Calculate a plurality of distance values from the time difference or phase difference between the plurality of transmission waves and the reception wave to the object,
A distance measurement method for a laser radar device, wherein a distance value in which a received wave is not saturated and the intensity of the received wave is high is output as a distance measurement distance among the plurality of distance values. A first transmitter and a second transmitter for transmitting transmission waves of a first wavelength and a second wavelength, each of which is a pulse wave or a modulated wave, toward an object;
A first receiver and a second receiver for separately receiving a first wave and a second wave received by the transmission wave reflected by an object;
A first distance value calculator and a second distance value calculator for calculating a distance value from the time difference or phase difference between the transmission wave and the reception wave of the first wavelength and the second wavelength, respectively,
A saturation detector for detecting the presence or absence of saturation of the received wave of the first wavelength or the second wavelength;
A distance value synthesizer that synthesizes an appropriate distance from a plurality of distance values obtained by the first distance value calculator and the second distance value calculator;
The transmission intensity of the first transmitter and the second transmitter, or the reception amplification factor of the first receiver and the second receiver are different,
A laser radar device characterized in that, among the plurality of distance values, a distance value in which the received wave is not saturated and the intensity of the received wave is high is output as a distance measurement distance. Transmitting first and second wavelength transmission waves, each composed of a pulse wave or a modulated wave, toward an object,
The transmission wave receives the first and second wavelength reception waves reflected by the object separately and receives the transmission intensity of the first and second wavelengths, or the reception amplification of the first and second wavelengths. Different rates,
Calculating a distance value from the time difference or phase difference between the transmission wave and the reception wave of the first wavelength and the second wavelength to the object, respectively;
Detecting the presence or absence of saturation of the received wave of the first wavelength or the second wavelength;
A distance measurement method for a laser radar device, wherein a distance value in which a received wave is not saturated and the intensity of the received wave is high is output as a distance measurement distance among the plurality of distance values. A transmitter for transmitting a transmission wave composed of a pulse wave or a modulation wave toward an object;
A transmission variable focus device for changing a transmission spread angle of the transmission wave before transmission;
A receiver for receiving a received wave reflected by an object from the transmitted wave;
A variable focus for reception that changes the measurement focus of the received wave before reception;
A distance value calculator for calculating a distance value from the time difference or phase difference between the transmitted wave and the received wave to the object;
A saturation detector for detecting the presence or absence of saturation of the received wave;
A distance value synthesizer that synthesizes an appropriate distance from a plurality of distance values obtained by the distance value calculator;
A laser radar characterized by dynamically changing a transmission divergence angle or a measurement focus at a predetermined time interval, and outputting a distance value in which a received wave is not saturated and the intensity of the received wave is high as a distance measured. apparatus. At a predetermined time interval, dynamically changing the transmission divergence angle or measurement focus, transmitting a plurality of transmission waves toward the object, and receiving a plurality of reception waves reflected by the object,
Detecting the presence or absence of saturation of the received wave,
Calculate a plurality of distance values from the time difference or phase difference between the plurality of transmission waves and the reception wave to the object,
A distance measurement method for a laser radar device, wherein a distance value in which a received wave is not saturated and the intensity of the received wave is high is output as a distance measurement distance among the plurality of distance values.

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