DISTANCE MEASURING DEVICE

• US 20190086522A1
• Filed: 03/14/2018
• Published: 03/21/2019
• Est. Priority Date: 09/15/2017
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Electronic Devices & Storage Corporation (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Electronic Devices & Storage Corporation (Toshiba Corporation)
• Inventors: KUBOTA, Hiroshi, Matsumoto, Nobu, Oota, Yutaka, Sato, Saki
• Granted Patent: US 10,866,311 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 7/4863 Detector arrays, e.g. charge-transfer gates
• CPC Class Codes: G01S 7/4865 Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak peak detection in noise, signal conditioning G01S7/487
• CPC Class Codes: G01S 7/487 Extracting wanted echo signals , e.g. pulse detection

Abstract

A distance measuring device according to an embodiment includes a light source, an irradiation optical system, a light-receiving optical system, a sensor, an extractor, an adjuster, a signal generator, and a distance measurer. The light source intermittently emits laser light. The irradiation optical system reflects the laser light. The light-receiving optical system receives reflected light of the laser light via the mirror. The sensor includes a plurality of light receiving elements. The extractor extracts light receiving elements used for measurement of a distance to the measurement target object. The adjuster adjusts, according to an amplification factor corresponding to the light receiving elements extracted by the extractor, signal values of the electric signals of the light receiving elements. The signal generator generates time-series signals for measurement on the basis of the electric signals adjusted by the adjuster. The distance measurer measures the distance to the measurement target object.

Claims

1. A distance measuring device comprising:

a light source configured to intermittently emit laser light;

an irradiation optical system configured to reflect the laser light emitted by the light source on a mirror or a mechanical mechanism including lens, which cyclically changes an angle of an incident surface with respect to the laser light, and irradiate the laser light on a measurement target object;

a light-receiving optical system configured to receive reflected light of the laser light via the mirror or the mechanical mechanism including lens;

a sensor including a plurality of light receiving elements configured to convert the reflected light received via the light-receiving optical system into an electric signal;

an extractor configured to extract a light receiving element used for measurement of a distance to the measurement target object among the plurality of light receiving elements;

an adjuster configured to adjust, according to an amplification factor corresponding to the light receiving element extracted by the extractor, a signal value of the electric signal of the light receiving element;

a signal generator configured to generate time-series signals for measurement on the basis of the electric signal adjusted by the adjuster; and

a distance measurer configured to measure the distance to the measurement target object on the basis of a time difference between light emission timing of the laser light and timing of a peak position of the signal for measurement.

2. The distance measuring device according to claim 1, wherein the extractor extracts the light receiving element corresponding to a position on a light receiving surface of the sensor on which the reflected light reflected by the mirror is made incident.

3. The distance measuring device according to claim 1, wherein the extractor changes, according to the angle of the mirror and an elapsed time from the light emission timing of the laser light, the light receiving element used for the distance measurement and extracts the light receiving element.

4. The distance measuring device according to claim 1, wherein the extractor extracts the light receiving element on the basis of angular velocity of the mirror.

5. The distance measuring device according to claim 1, wherein, as an elapsed time from the light emission timing of the laser light increases, the extractor extracts a light receiving element in a position further away from an optical axis center of the light-receiving optical system.

6. The distance measuring device according to claim 1, wherein, as angular velocity of the mirror increases, the extractor sets, in a position further away from an optical axis center of the light-receiving optical system, a position of a light receiving element extracted when a predetermined time elapses from the light emission timing of the laser light.

7. The distance measuring device according to claim 1, wherein the adjustor sets an amplification factor of the light receiving element extracted by the extractor larger than an amplification factor of a light receiving element not extracted by the extractor among the light receiving elements included in the sensor.

8. The distance measuring device according to claim 1, wherein the adjuster sets an amplification factor of a light receiving element not extracted by the extractor to 0.

9. The distance measuring device according to claim 1, wherein

the mirror is a one-axis rotary mirror,

the sensor includes three or more light receiving elements disposed along a moving direction of the reflected light on a light receiving surface of the sensor that moves according to rotation of the rotary mirror,

the adjustor includes a plurality of adjustors corresponding to the respective three or more light receiving elements and configured to adjust magnitudes of output signals of the corresponding light receiving elements, and

the distance measuring device further comprises at least one AD converter connected to a pair or more of the adjustors corresponding to alternately disposed respective light receiving elements among the three or more light receiving elements.

10. The distance measuring device according to claim 1, wherein the mirror alternately repeats rotation in one direction and rotation in another direction, which is an opposite direction of the one direction, and shifts light emission timing of the light source at a time when the mirror is rotating in the one direction and light emission timing of the light source at a time when the mirror is rotating in the other direction.

20. The distance measuring device according to claim 1, further comprising a rotation table configured to rotate the light source, the irradiation optical system, the light-receiving optical system, and the sensor.

11. A distance measuring device comprising:

a light source configured to intermittently emit laser light;

an irradiation optical system configured to reflect the laser light emitted by the light source on a mirror or a mechanical mechanism including lens, which cyclically changes an angle of an incident surface with respect to the laser light, and irradiate the laser light on a measurement target object;

a light-receiving optical system configured to receive reflected light of the laser light via the mirror or the mechanical mechanism including lens;

a sensor including a plurality of light receiving elements configured to convert the reflected light received via the light-receiving optical system into an electric signal;

an AD converter configured to generate a signal for measurement on the basis of electric signals output from the plurality of light receiving elements;

an extractor configured to extract a light receiving element used for measurement of a distance to the measurement target object;

an adjuster configured to adjust, according to an amplification factor corresponding to the light receiving element extracted by the extractor, a signal value of the signal for measurement; and

a distance measurer configured to measure the distance to the measurement target object on the basis of a time difference between light emission timing of the laser light and timing of a peak position of the signal for measurement adjusted by the adjuster.

12. The distance measuring device according to claim 11, wherein the extractor extracts the light receiving element corresponding to a position on a light receiving surface of the sensor on which the reflected light reflected by the mirror is made incident.

13. The distance measuring device according to claim 11, wherein the extractor changes, according to the angle of the mirror and an elapsed time from the light emission timing of the laser light, the light receiving element used for the distance measurement and extracts the light receiving element.

14. The distance measuring device according to claim 11, wherein the extractor extracts the light receiving element on the basis of angular velocity of the mirror.

15. The distance measuring device according to claim 11, wherein, as an elapsed time from the light emission timing of the laser light increases, the extractor extracts a light receiving element in a position further away from an optical axis center of the light-receiving optical system.

16. The distance measuring device according to claim 11, wherein, as angular velocity of the mirror increases, the extractor sets, in a position further away from an optical axis center of the light-receiving optical system, a position of a light receiving element extracted when a predetermined time elapses from the light emission timing of the laser light.

17. The distance measuring device according to claim 11, wherein the adjustor sets an amplification factor of the light receiving element extracted by the extractor larger than an amplification factor of a light receiving element not extracted by the extractor among the light receiving elements included in the sensor.

18. The distance measuring device according to claim 11, wherein

the mirror is a one-axis rotary mirror,

the sensor includes three or more light receiving elements disposed along a moving direction of the reflected light on a light receiving surface of the sensor that moves according to rotation of the rotary mirror,

the adjustor includes a plurality of adjustors corresponding to the respective three or more light receiving elements and configured to adjust magnitudes of output signals of the corresponding light receiving elements, and

the distance measuring device further comprises at least one AD converter connected to a pair or more of the adjustors corresponding to alternately disposed respective light receiving elements among the three or more light receiving elements.

19. A distance measuring device comprising:

a light source configured to intermittently emit laser light;

a mirror configured to perform, with respect to a rotation axis, rotation in one direction and rotation in another direction, which is an opposite direction of the one direction;

an irradiation optical system configured to irradiate the laser beam emitted by the light source on a measurement target object via the mirror; and

a controller configured to perform control for shifting light emission timing of the light source at a time when the mirror is rotating in the one direction and light emission timing of the light source at a time when the mirror is rotating in the other direction.