WO2019148475A1 - Methods and systems with dynamic gain determination - Google Patents

Methods and systems with dynamic gain determination Download PDF

Info

Publication number
WO2019148475A1
WO2019148475A1 PCT/CN2018/075180 CN2018075180W WO2019148475A1 WO 2019148475 A1 WO2019148475 A1 WO 2019148475A1 CN 2018075180 W CN2018075180 W CN 2018075180W WO 2019148475 A1 WO2019148475 A1 WO 2019148475A1
Authority
WO
WIPO (PCT)
Prior art keywords
measurement
intensity
characteristic
gain
light
Prior art date
Application number
PCT/CN2018/075180
Other languages
French (fr)
Inventor
Peiyan CAO
Yurun LIU
Original Assignee
Shenzhen Genorivision Technology Co. Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shenzhen Genorivision Technology Co. Ltd. filed Critical Shenzhen Genorivision Technology Co. Ltd.
Priority to PCT/CN2018/075180 priority Critical patent/WO2019148475A1/en
Priority to TW108104244A priority patent/TWI791758B/en
Publication of WO2019148475A1 publication Critical patent/WO2019148475A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
    • H01L27/144—Devices controlled by radiation
    • H01L27/1443—Devices controlled by radiation with at least one potential jump or surface barrier
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/08—Systems determining position data of a target for measuring distance only
    • G01S17/10—Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • G01S7/4868—Controlling received signal intensity or exposure of sensor
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
    • H01L27/144—Devices controlled by radiation
    • H01L27/146—Imager structures
    • H01L27/14601—Structural or functional details thereof
    • H01L27/14609—Pixel-elements with integrated switching, control, storage or amplification elements

Definitions

  • the disclosure herein relates to light detection, especially light detection used for range finding and image formation, such as in a lidar.
  • a lidar uses light for detection, range finding and mapping.
  • a lidar may include several major components: a light source, optics, and a detector.
  • Lidar may have a wide range of applications.
  • autonomous vehicles e.g., driverless cars
  • a lidar may use a lidar for obstacle detection and collision avoidance to navigate safely through environments.
  • a lidar may be mounted on an autonomous vehicle and monitors the environment around the vehicle. The lidar may provide data for determining the existence, identities, locations and structures of obstacles in the environment.
  • a method comprising: obtaining, under a first gain, a first measurement of an intensity of light scattered by a portion of a target scene; obtaining, under the first gain, a first measurement of a characteristic of the portion, based on the light scattered by the portion; obtaining, under a second gain, a second measurement of the intensity; obtaining, under the second gain, a second measurement of the characteristic, based on the light scattered by the portion; selecting among the first measurement of the characteristic and the second measurement of the characteristic, based on the first measurement of the intensity and the second measurement of the intensity.
  • the characteristic is a function of a distance between the portion and a source of the light.
  • the characteristic is a function of a time for the light to travel from a source of the light to the portion.
  • selecting among the first measurement of the characteristic and the second measurement of the characteristic comprises comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of a detector.
  • selecting among the first measurement of the characteristic and the second measurement of the characteristic comprises comparing the first measurement of the intensity relative to a dynamic range of a detector with the second measurement of the intensity relative to the dynamic range of the detector.
  • selecting among the first measurement of the characteristic and the second measurement of the characteristic comprises determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of a detector.
  • the method further comprises generating an image of the target scene, the image comprising a measurement of the characteristic selected among the first measurement of the characteristic and the second measurement of the characteristic.
  • the first measurement of the intensity and the second measurement of the intensity are digital signals.
  • the light is a laser.
  • the light is infrared.
  • a method comprising: obtaining, under a first gain, a first measurement of an intensity of light scattered by a portion of a target scene; obtaining, under a second gain, a second measurement of the intensity; determining a third gain based on the first measurement of the intensity and the second measurement of the intensity; obtaining, under the third gain, a measurement of a characteristic of the portion, based on the light scattered by the portion.
  • the characteristic is a function of a distance between the portion and a source of the light.
  • the characteristic is a function of a time for the light to travel from a source of the light to the portion.
  • determining the third gain comprises comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of a detector.
  • determining the third gain comprises comparing the first measurement of the intensity relative to a dynamic range of a detector with the second measurement of the intensity relative to the dynamic range of the detector.
  • determining the third gain comprises determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of a detector.
  • the method further comprises generating an image of the target scene, the image comprising the measurement of the characteristic.
  • the first measurement of the intensity and the second measurement of the intensity are digital signals.
  • the light is a laser.
  • the light is infrared.
  • a system comprising: a light source configured to direct light toward a portion of a target scene; a detector configured: to obtain, under a first gain, a first measurement of an intensity of light scattered by the portion, to obtain, under the first gain, a first measurement of a characteristic of the portion, based on the light scattered by the portion, to obtain, under a second gain, a second measurement of the intensity, and to obtain, under the second gain, a second measurement of the characteristic, based on the light scattered by the portion; and a processor configured to select among the first measurement of the characteristic and the second measurement of the characteristic, based on the first measurement of the intensity and the second measurement of the intensity.
  • the characteristic is a function of a distance between the portion and the light source.
  • the characteristic is a function of a time for the light to travel from the light source to the portion.
  • the processor is configured to select among the first measurement of the characteristic and the second measurement of the characteristic by comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of the detector.
  • the processor is configured to select among the first measurement of the characteristic and the second measurement of the characteristic by comparing the first measurement of the intensity relative to a dynamic range of the detector with the second measurement of the intensity relative to the dynamic range of the detector.
  • the processor is configured to select among the first measurement of the characteristic and the second measurement of the characteristic by determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of the detector.
  • the processor is further configured to generate an image of the target scene, the image comprising a measurement of the characteristic selected among the first measurement of the characteristic and the second measurement of the characteristic.
  • the first measurement of the intensity and the second measurement of the intensity are digital signals.
  • the light is a laser.
  • the light is infrared.
  • a system comprising: a light source configured to direct light toward a portion of a target scene; a detector configured: to obtain, under a first gain, a first measurement of an intensity of light scattered by the portion, to obtain, under a second gain, asecond measurement of the intensity; and a processor configured to determine a third gain based on the first measurement of the intensity and the second measurement of the intensity; wherein the detector is further configured to obtain, under the third gain, a measurement of a characteristic of the portion, based on the light scattered by the portion.
  • the characteristic is a function of a distance between the portion and the light source.
  • the characteristic is a function of a time for the light to travel from the light source to the portion.
  • the processor is configured to determine the third gain by comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of the detector.
  • the processor is configured to determine the third gain by comparing the first measurement of the intensity relative to a dynamic range of the detector with the second measurement of the intensity relative to the dynamic range of the detector.
  • the processor is configured to determine the third gain by determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of the detector.
  • the processor is further configured to generate an image of the target scene, the image comprising the measurement of the characteristic.
  • the first measurement of the intensity and the second measurement of the intensity are digital signals.
  • the light is a laser.
  • the light is infrared.
  • Fig. 1 schematically shows a system, according to an embodiment.
  • Fig. 2A schematically shows a method according to an embodiment.
  • Fig. 2B, Fig. 2C, Fig. 2D and Fig. 2E each schematically show details of a step of the method of Fig. 2A.
  • Fig. 3A schematically shows a method according to an embodiment.
  • Fig. 3B, Fig. 3C, Fig. 3D and Fig. 3E each schematically show details of a step of the method of Fig. 3A.
  • Fig. 1 schematically shows a system 100, according to an embodiment.
  • the system 100 may comprise a light source 102, a detector 104, and a processor 109.
  • the light source 102 may be configured to direct light toward a portion (e.g., a line or a spot) of a target scene 108.
  • the light may be a laser.
  • the light may be infrared.
  • the light source 102 may be further configured to scan the light across the target scene 108 in one or more directions.
  • the light directed toward the portion may be scattered (e.g., reflected) by the portion.
  • Some of the light scattered by the portion may be received by the detector 104.
  • the system 100 may have optics 106 configured to shape the light scattered by the portion before it is received by the detector 104.
  • the detector 104 may be configured to measure a characteristic of the portion of the target scene 108 based on the light scattered by the portion.
  • the characteristic may be a function of the distance between the portion and the light source 102 or a function of the time for the light to travel between the light source 102 and the portion.
  • the light source 102 may direct a pulse of light toward the portion and the detector 104 may measure the characteristic using the fraction of the light scattered by the portion that originated from the pulse.
  • the detector 104 may amplify the light scattered by the portion.
  • the amplification may be in a form of optical amplification, e.g., using a photomultiplier, where the light scattered by the portion is amplified into a stronger optical signal (e.g., more intense light) .
  • the amplification may be in a form of electric amplification, e.g., using a photodetector to convert the light scattered by the portion into an electric signal and using an electronic amplifier to amplify the electric signal.
  • the magnitude of the amplification may be expressed by a gain.
  • a gain measures the output of the amplification relative to the input.
  • the gain may be a ratio of the intensity of the stronger optical signal to the intensity of the light scattered by the portion and received by the detector 104.
  • the gain may be a ratio of the magnitude of the electric signal after the electronic amplifier and the magnitude of the electric signal before the electronic amplifier.
  • the magnitude of the light scattered by the portion may depend on many factors, such as the distance of the portion and the light source 102. In an example, the magnitude of the light scattered by the portion is inversely proportional the fourth power of the distance. Therefore, the magnitude of the light scattered by the portion may be anywhere in a very wide range spanning orders of magnitude.
  • the processor 109 may process data from the detector 104 and adjust the detector 104.
  • the processor 109 may adjust the gain of the detector 104 to accommodate the wide range of the magnitude of the light scattered by the portion.
  • the processor 109 may adjust the gain of the detector 104 so that the light scattered by the portion and received by the detector 104 is not too close to the boundaries of the dynamic range of the detector 104.
  • the processor 109 may select among data from the detector 104.
  • Fig. 2A schematically shows a method according to an embodiment.
  • the first measurement I1 of an intensity of the light scattered by the portion of the target scene is obtained under the first gain G1 (e.g., with the detector 104) .
  • the first measurement C1 of the characteristic of the portion is obtained, based on the light scattered by the portion, under the first gain G1 (e.g., with the detector 104) .
  • the second measurement I2 of the intensity is obtained under the second gain G2 (e.g., with the detector 104) .
  • the second measurement C2 of the characteristic is obtained, based on the light scattered by the portion, under the second gain G2 (e.g., with the detector 104) .
  • the measurements I1 and I2 of the intensity may be at the same time or slightly different time.
  • I1 and I2 may be digitized waveforms of the intensity as a function of time. Under different gains G1 and G2, I1 and I2 may be quite different despite that they are measurements of the same intensity. For example, if the gain is chosen so that the intensity is close to the lower boundary of the dynamic range, the measurement of the intensity (I1 in this example) may have large quantization errors; if the gain is chosen so that the intensity is not close to the lower boundary of the dynamic range, the measurement of the intensity (I2 in this example) may have small quantization errors.
  • the measurements C1 and C2 of the characteristic may be obtained by measuring the intensity as a function of time, for example, the time at which a peak of the intensity arrives at the detector 104.
  • One measurement of the characteristic is selected (e.g., using the processor 109) among the first measurement C1 of the characteristic and the second measurement C2 of the characteristic, based on the first measurement I1 of the intensity and the second measurement I2 of the intensity.
  • C2 is selected because I2 has smaller quantization errors than I1.
  • the selection among the first measurement C1 of the characteristic and the second measurement C2 of the characteristic may include comparing I1 or I2 with the dynamic range DYM of the detector 104.
  • I1 and I2 relative to the dynamic range DYM is represented by “I1
  • the selection among the first measurement C1 of the characteristic and the second measurement C2 of the characteristic may include comparing I1
  • the selection among the first measurement C1 of the characteristic and the second measurement C2 of the characteristic may include determining whether I1 or I2 falls out of the dynamic range. For example, if I1
  • an image 999 of the target scene 108 (e.g., distances of each point in the target scene to the light source) may be generated where the image includes the one measurement of the characteristic selected among C1 and C2.
  • Fig. 3A schematically shows a method according to an embodiment.
  • the first measurement I1 of an intensity of the light scattered by the portion of the target scene is obtained under the first gain G1 (e.g., with the detector 104) .
  • the second measurement I2 of the intensity is obtained under the second gain G2 (e.g., with the detector 104) .
  • a third gain G3 is determined (e.g., using the processor 109) based on the first measurement I1 of the intensity and the second measurement I2 of the intensity.
  • G3 may be selected among G1 and G2 based on I1 and I2;
  • G3 may be a weighted average of G1 and G2 where the weights are determined based on I1 and I2.
  • a measurement C of the characteristic of the portion is obtained, based on the light scattered by the portion, under the third gain G3 (e.g., with the detector 104) .
  • the measurements I1 and I2 of the intensity may be at the same time or slightly different time.
  • I1 and I2 may be digitized waveforms of the intensity as a function of time. Under different gains G1 and G2, I1 and I2 may be quite different despite that they are measurements of the same intensity.
  • the measurement of the intensity may have large quantization errors; if the gain is chosen so that the intensity is not close to the lower boundary of the dynamic range, the measurement of the intensity (I2 in this example) may have small quantization errors.
  • the measurement C of the characteristic may be obtained by measuring the intensity as a function of time, for example, the time at which a peak of the intensity arrives at the detector 104.
  • determining the third gain G3 may include comparing I1 or I2 with the dynamic range DYM of the detector 104.
  • I1 and I2 relative to the dynamic range DYM is represented by “I1
  • determining the third gain G3 may include comparing I1
  • determining the third gain G3 may include determining whether I1 or I2 falls out of the dynamic range. For example, if I1
  • an image 998 of the target scene 108 (e.g., distances of each point in the target scene to the light source) may be generated where the image includes the measurement C.
  • the measurements C in the points of the image 998 are not necessarily under the same gain. Namely, G3 may be different for different points.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Remote Sensing (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Optical Radar Systems And Details Thereof (AREA)
  • Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
  • Transplanting Machines (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

A method and system with dynamic gain determination is provided. The method comprises: obtaining, under a first gain (G1), a first measurement (I1) of an intensity of light scattered by a portion of a target scene (108); obtaining, under the first gain (G1), a first measurement (C1) of a characteristic of the portion, based on the light scattered by the portion; obtaining, under a second gain (G2), a second measurement (I2) of the intensity; obtaining, under the second gain (G2), a second measurement (C2) of the characteristic, based on the light scattered by the portion; selecting among the first measurement(C1) of the characteristic and the second measurement (C2) of the characteristic, based on the first measurement (I1) of the intensity and the second measurement (I2) of the intensity.

Description

METHODS AND SYSTEMS WITH DYNAMIC GAIN DETERMINATION Technical Field
The disclosure herein relates to light detection, especially light detection used for range finding and image formation, such as in a lidar.
Background
A lidar uses light for detection, range finding and mapping. A lidar may include several major components: a light source, optics, and a detector. Lidar may have a wide range of applications. For example, autonomous vehicles (e.g., driverless cars) may use a lidar for obstacle detection and collision avoidance to navigate safely through environments. A lidar may be mounted on an autonomous vehicle and monitors the environment around the vehicle. The lidar may provide data for determining the existence, identities, locations and structures of obstacles in the environment.
Summary
Disclosed herein is a method comprising: obtaining, under a first gain, a first measurement of an intensity of light scattered by a portion of a target scene; obtaining, under the first gain, a first measurement of a characteristic of the portion, based on the light scattered by the portion; obtaining, under a second gain, a second measurement of the intensity; obtaining, under the second gain, a second measurement of the characteristic, based on the light scattered by the portion; selecting among the first measurement of the characteristic and the second measurement of the characteristic, based on the first measurement of the intensity and the second measurement of the intensity.
According to an embodiment, the characteristic is a function of a distance between the portion and a source of the light.
According to an embodiment, the characteristic is a function of a time for the light to travel from a source of the light to the portion.
According to an embodiment, selecting among the first measurement of the characteristic and the second measurement of the characteristic comprises comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of a detector.
According to an embodiment, selecting among the first measurement of the characteristic and the second measurement of the characteristic comprises comparing the first measurement of the intensity relative to a dynamic range of a detector with the second measurement of the intensity relative to the dynamic range of the detector.
According to an embodiment, selecting among the first measurement of the characteristic and the second measurement of the characteristic comprises determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of a detector.
According to an embodiment, the method further comprises generating an image of the target scene, the image comprising a measurement of the characteristic selected among the first measurement of the characteristic and the second measurement of the characteristic.
According to an embodiment, the first measurement of the intensity and the second measurement of the intensity are digital signals.
According to an embodiment, the light is a laser.
According to an embodiment, the light is infrared.
Disclosed herein is a method comprising: obtaining, under a first gain, a first measurement of an intensity of light scattered by a portion of a target scene; obtaining, under a second gain, a second measurement of the intensity; determining a third gain based on the first measurement of the intensity and the second measurement of the intensity; obtaining, under the third gain, a measurement of a characteristic of the portion, based on the light scattered by the portion.
According to an embodiment, the characteristic is a function of a distance between the portion and a source of the light.
According to an embodiment, the characteristic is a function of a time for the light to travel from a source of the light to the portion.
According to an embodiment, determining the third gain comprises comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of a detector.
According to an embodiment, determining the third gain comprises comparing the first measurement of the intensity relative to a dynamic range of a detector with the second measurement of the intensity relative to the dynamic range of the detector.
According to an embodiment, determining the third gain comprises determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of a detector.
According to an embodiment, the method further comprises generating an image of the target scene, the image comprising the measurement of the characteristic.
According to an embodiment, the first measurement of the intensity and the second measurement of the intensity are digital signals.
According to an embodiment, the light is a laser.
According to an embodiment, the light is infrared.
Disclosed herein is a system comprising: a light source configured to direct light toward a portion of a target scene; a detector configured: to obtain, under a first gain, a first measurement of an intensity of light scattered by the portion, to obtain, under the first gain, a first measurement of a characteristic of the portion, based on the light scattered by the portion, to obtain, under a second gain, a second measurement of the intensity, and to obtain, under the second gain, a second measurement of the characteristic, based on the light scattered by the portion; and a processor configured to select among the first measurement of the characteristic and the second measurement of the characteristic, based on the first measurement of the intensity and the second measurement of the intensity.
According to an embodiment, the characteristic is a function of a distance between the portion and the light source.
According to an embodiment, the characteristic is a function of a time for the light to travel from the light source to the portion.
According to an embodiment, the processor is configured to select among the first measurement of the characteristic and the second measurement of the characteristic by comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of the detector.
According to an embodiment, the processor is configured to select among the first measurement of the characteristic and the second measurement of the characteristic by comparing the first measurement of the intensity relative to a dynamic range of the detector with the second measurement of the intensity relative to the dynamic range of the detector.
According to an embodiment, the processor is configured to select among the first measurement of the characteristic and the second measurement of the characteristic by determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of the detector.
According to an embodiment, the processor is further configured to generate an image of the target scene, the image comprising a measurement of the characteristic selected among the first measurement of the characteristic and the second measurement of the characteristic.
According to an embodiment, the first measurement of the intensity and the second measurement of the intensity are digital signals.
According to an embodiment, the light is a laser.
According to an embodiment, the light is infrared.
Disclosed herein is a system comprising: a light source configured to direct light toward a portion of a target scene; a detector configured: to obtain, under a first gain, a first measurement of an intensity of light scattered by the portion, to obtain, under a second gain, asecond measurement of the intensity; and a processor configured to determine a third gain based on the first measurement of the intensity and the second measurement of the intensity; wherein the detector is further configured to obtain, under the third gain, a measurement of a characteristic of the portion, based on the light scattered by the portion.
According to an embodiment, the characteristic is a function of a distance between the portion and the light source.
According to an embodiment, the characteristic is a function of a time for the light to travel from the light source to the portion.
According to an embodiment, the processor is configured to determine the third gain by comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of the detector.
According to an embodiment, the processor is configured to determine the third gain by comparing the first measurement of the intensity relative to a dynamic range of the detector with the second measurement of the intensity relative to the dynamic range of the detector.
According to an embodiment, the processor is configured to determine the third gain by determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of the detector.
According to an embodiment, the processor is further configured to generate an image of the target scene, the image comprising the measurement of the characteristic.
According to an embodiment, the first measurement of the intensity and the second measurement of the intensity are digital signals.
According to an embodiment, the light is a laser.
According to an embodiment, the light is infrared.
Brief Description of Figures
Fig. 1 schematically shows a system, according to an embodiment.
Fig. 2A schematically shows a method according to an embodiment.
Fig. 2B, Fig. 2C, Fig. 2D and Fig. 2E each schematically show details of a step of the method of Fig. 2A.
Fig. 3A schematically shows a method according to an embodiment.
Fig. 3B, Fig. 3C, Fig. 3D and Fig. 3E each schematically show details of a step of the method of Fig. 3A.
Detailed Description
Fig. 1 schematically shows a system 100, according to an embodiment. The system 100 may comprise a light source 102, a detector 104, and a processor 109.
The light source 102 may be configured to direct light toward a portion (e.g., a line or a spot) of a target scene 108. The light may be a laser. The light may be infrared. The light source 102 may be further configured to scan the light across the target scene 108 in one or more directions. The light directed toward the portion may be scattered (e.g., reflected) by the portion. Some of the light scattered by the portion may be received by the detector 104. The system 100 may have optics 106 configured to shape the light scattered by the portion before it is received by the detector 104.
The detector 104 may be configured to measure a characteristic of the portion of the target scene 108 based on the light scattered by the portion. For example, the characteristic may be a function of the distance between the portion and the light source 102 or a function of the time for the light to travel between the light source 102 and the portion. The light source 102 may direct a pulse of light toward the portion and the detector 104 may measure the characteristic using the fraction of the light scattered by the portion that originated from the pulse.
The detector 104 may amplify the light scattered by the portion. The amplification may be in a form of optical amplification, e.g., using a photomultiplier, where the light scattered by the portion is amplified into a stronger optical signal (e.g., more intense light) . The amplification may be in a form of electric amplification, e.g., using a photodetector to convert the light scattered by the portion into an electric signal and using an electronic amplifier to amplify the electric signal. The magnitude of the amplification may be expressed by a gain. A gain measures the output of the amplification relative to the input. For example, the gain may be a ratio of the intensity of the stronger optical signal to the intensity of the light scattered by the portion and received by the detector 104. For example, the gain may be a ratio of the magnitude of the electric signal after the electronic amplifier and the magnitude of the electric signal before the electronic amplifier. The magnitude of the light scattered by the portion may depend on many factors, such as the distance of the portion and the light source 102. In an example, the magnitude of the light scattered by the portion is inversely proportional the fourth power of the distance. Therefore, the magnitude of the light scattered by the portion may be anywhere in a very wide range spanning orders of magnitude.
The processor 109, which may be integrated with the detector 104, may process data from the detector 104 and adjust the detector 104. For example, the processor 109 may adjust the gain of the detector 104 to accommodate the wide range of the magnitude of the light scattered by the portion. For example, the processor 109 may adjust the gain of the detector 104 so that the light scattered by the portion and received by the detector 104 is not too close to the boundaries of the dynamic range of the detector 104. For example, the processor 109 may select among data from the detector 104.
Fig. 2A schematically shows a method according to an embodiment. The first measurement I1 of an intensity of the light scattered by the portion of the target scene is obtained under the first gain G1 (e.g., with the detector 104) . The first measurement C1 of the characteristic of the portion is obtained, based on the light scattered by the portion, under the first gain G1 (e.g., with the detector 104) . The second measurement I2 of the intensity is obtained under the second gain G2 (e.g., with the detector 104) . The second measurement C2 of the characteristic is obtained, based on the light scattered by the portion, under the second gain G2 (e.g., with the detector 104) . The measurements I1 and I2 of the intensity may be at the same time or slightly different time. I1 and I2 may be digitized waveforms of the intensity as a function of time. Under different gains G1 and G2, I1 and I2 may be quite different despite that they are measurements of the same intensity. For example, if the gain is chosen so that the intensity is close to the lower boundary of the dynamic range, the measurement of the intensity (I1 in this example) may have large quantization errors; if the gain is chosen so that the intensity is not close to the lower boundary of the dynamic range, the measurement of the intensity (I2 in this example) may have small quantization errors. The measurements C1 and C2 of the characteristic may be obtained by measuring the intensity as a function of time, for example, the time at which a peak of the intensity arrives at the detector 104. If the quantization errors are large, the error of the time at which a peak of the intensity arrives at the detector 104 and thus the error in the measurement of the characteristic are also large. One measurement of the characteristic is selected (e.g., using the processor 109) among the first measurement C1 of the characteristic and the second measurement C2 of the characteristic, based on the first measurement I1 of the intensity and the second measurement  I2 of the intensity. In this example, C2 is selected because I2 has smaller quantization errors than I1.
As schematically shown in Fig. 2B, the selection among the first measurement C1 of the characteristic and the second measurement C2 of the characteristic may include comparing I1 or I2 with the dynamic range DYM of the detector 104. I1 and I2 relative to the dynamic range DYM is represented by “I1|DYM” and “I2|DYM” respectively.
As schematically shown in Fig. 2C, the selection among the first measurement C1 of the characteristic and the second measurement C2 of the characteristic may include comparing I1|DYM with I2|DYM. For example, if I1|DYM is at 10%and I2|DYM is at 90%of the dynamic range, C2 should be selected instead of C1.
As schematically shown in Fig. 2D, the selection among the first measurement C1 of the characteristic and the second measurement C2 of the characteristic may include determining whether I1 or I2 falls out of the dynamic range. For example, if I1|DYM is at 10%and I2|DYM is at 100%of the dynamic range (i.e., I2 is saturated) , C1 should be selected instead of C2.
As schematically shown in Fig. 2E, an image 999 of the target scene 108 (e.g., distances of each point in the target scene to the light source) may be generated where the image includes the one measurement of the characteristic selected among C1 and C2.
Fig. 3A schematically shows a method according to an embodiment. The first measurement I1 of an intensity of the light scattered by the portion of the target scene is obtained under the first gain G1 (e.g., with the detector 104) . The second measurement I2 of the intensity is obtained under the second gain G2 (e.g., with the detector 104) . A third gain G3 is determined (e.g., using the processor 109) based on the first measurement I1 of the intensity  and the second measurement I2 of the intensity. For example, G3 may be selected among G1 and G2 based on I1 and I2; G3 may be a weighted average of G1 and G2 where the weights are determined based on I1 and I2. A measurement C of the characteristic of the portion is obtained, based on the light scattered by the portion, under the third gain G3 (e.g., with the detector 104) . The measurements I1 and I2 of the intensity may be at the same time or slightly different time. I1 and I2 may be digitized waveforms of the intensity as a function of time. Under different gains G1 and G2, I1 and I2 may be quite different despite that they are measurements of the same intensity. For example, if the gain is chosen so that the intensity is close to the lower boundary of the dynamic range, the measurement of the intensity (I1 in this example) may have large quantization errors; if the gain is chosen so that the intensity is not close to the lower boundary of the dynamic range, the measurement of the intensity (I2 in this example) may have small quantization errors. The measurement C of the characteristic may be obtained by measuring the intensity as a function of time, for example, the time at which a peak of the intensity arrives at the detector 104.
As schematically shown in Fig. 3B, determining the third gain G3 may include comparing I1 or I2 with the dynamic range DYM of the detector 104. I1 and I2 relative to the dynamic range DYM is represented by “I1|DYM” and “I2|DYM” respectively.
As schematically shown in Fig. 3C, determining the third gain G3 may include comparing I1|DYM with I2|DYM. For example, if I1|DYM is at 10%and I2|DYM is at 90%of the dynamic range, G2 should have a greater weight than G1 when G3 is a weighted average of G1 and G2.
As schematically shown in Fig. 3D, determining the third gain G3 may include determining whether I1 or I2 falls out of the dynamic range. For example, if I1|DYM is at 10% and I2|DYM is at 100%of the dynamic range (i.e., I2 is saturated) , G2 should have a smaller weight than G1 when G3 is a weighted average of G1 and G2.
As schematically shown in Fig. 3E, an image 998 of the target scene 108 (e.g., distances of each point in the target scene to the light source) may be generated where the image includes the measurement C. The measurements C in the points of the image 998 are not necessarily under the same gain. Namely, G3 may be different for different points.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims (40)

  1. A method comprising:
    obtaining, under a first gain, a first measurement of an intensity of light scattered by a portion of a target scene;
    obtaining, under the first gain, a first measurement of a characteristic of the portion, based on the light scattered by the portion;
    obtaining, under a second gain, a second measurement of the intensity;
    obtaining, under the second gain, a second measurement of the characteristic, based on the light scattered by the portion;
    selecting among the first measurement of the characteristic and the second measurement of the characteristic, based on the first measurement of the intensity and the second measurement of the intensity.
  2. The method of claim 1, wherein the characteristic is a function of a distance between the portion and a source of the light.
  3. The method of claim 1, wherein the characteristic is a function of a time for the light to travel from a source of the light to the portion.
  4. The method of claim 1, wherein selecting among the first measurement of the characteristic and the second measurement of the characteristic comprises comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of a detector.
  5. The method of claim 1, wherein selecting among the first measurement of the characteristic and the second measurement of the characteristic comprises comparing the first  measurement of the intensity relative to a dynamic range of a detector with the second measurement of the intensity relative to the dynamic range of the detector.
  6. The method of claim 1, wherein selecting among the first measurement of the characteristic and the second measurement of the characteristic comprises determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of a detector.
  7. The method of claim 1, further comprising generating an image of the target scene, the image comprising a measurement of the characteristic selected among the first measurement of the characteristic and the second measurement of the characteristic.
  8. The method of claim 1, wherein the first measurement of the intensity and the second measurement of the intensity are digital signals.
  9. The method of claim 1, wherein the light is a laser.
  10. The method of claim 1, wherein the light is infrared.
  11. A method comprising:
    obtaining, under a first gain, a first measurement of an intensity of light scattered by a portion of a target scene;
    obtaining, under a second gain, a second measurement of the intensity;
    determining a third gain based on the first measurement of the intensity and the second measurement of the intensity;
    obtaining, under the third gain, a measurement of a characteristic of the portion, based on the light scattered by the portion.
  12. The method of claim 11, wherein the characteristic is a function of a distance between the portion and a source of the light.
  13. The method of claim 11, wherein the characteristic is a function of a time for the light to travel from a source of the light to the portion.
  14. The method of claim 11, wherein determining the third gain comprises comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of a detector.
  15. The method of claim 11, wherein determining the third gain comprises comparing the first measurement of the intensity relative to a dynamic range of a detector with the second measurement of the intensity relative to the dynamic range of the detector.
  16. The method of claim 11, wherein determining the third gain comprises determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of a detector.
  17. The method of claim 11, further comprising generating an image of the target scene, the image comprising the measurement of the characteristic.
  18. The method of claim 11, wherein the first measurement of the intensity and the second measurement of the intensity are digital signals.
  19. The method of claim 11, wherein the light is a laser.
  20. The method of claim 11, wherein the light is infrared.
  21. A system comprising:
    a light source configured to direct light toward a portion of a target scene;
    a detector configured:
    to obtain, under a first gain, a first measurement of an intensity of light scattered by the portion,
    to obtain, under the first gain, a first measurement of a characteristic of the portion, based on the light scattered by the portion,
    to obtain, under a second gain, a second measurement of the intensity, and
    to obtain, under the second gain, a second measurement of the characteristic, based on the light scattered by the portion; and
    a processor configured to select among the first measurement of the characteristic and the second measurement of the characteristic, based on the first measurement of the intensity and the second measurement of the intensity.
  22. The system of claim 21, wherein the characteristic is a function of a distance between the portion and the light source.
  23. The system of claim 21, wherein the characteristic is a function of a time for the light to travel from the light source to the portion.
  24. The system of claim 21, wherein the processor is configured to select among the first measurement of the characteristic and the second measurement of the characteristic by comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of the detector.
  25. The system of claim 21, wherein the processor is configured to select among the first measurement of the characteristic and the second measurement of the characteristic by comparing the first measurement of the intensity relative to a dynamic range of the detector with the second measurement of the intensity relative to the dynamic range of the detector.
  26. The system of claim 21, wherein the processor is configured to select among the first measurement of the characteristic and the second measurement of the characteristic by determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of the detector.
  27. The system of claim 21, wherein the processor is further configured to generate an image of the target scene, the image comprising a measurement of the characteristic selected among the first measurement of the characteristic and the second measurement of the characteristic.
  28. The system of claim 21, wherein the first measurement of the intensity and the second measurement of the intensity are digital signals.
  29. The system of claim 21, wherein the light is a laser.
  30. The system of claim 21, wherein the light is infrared.
  31. A system comprising:
    a light source configured to direct light toward a portion of a target scene;
    a detector configured:
    to obtain, under a first gain, a first measurement of an intensity of light scattered by the portion,
    to obtain, under a second gain, a second measurement of the intensity; and
    a processor configured to determine a third gain based on the first measurement of the intensity and the second measurement of the intensity;
    wherein the detector is further configured to obtain, under the third gain, a measurement of a characteristic of the portion, based on the light scattered by the portion.
  32. The system of claim 31, wherein the characteristic is a function of a distance between the portion and the light source.
  33. The system of claim 31, wherein the characteristic is a function of a time for the light to travel from the light source to the portion.
  34. The system of claim 31, wherein the processor is configured to determine the third gain by comparing the first measurement of the intensity or the second measurement of the intensity with a dynamic range of the detector.
  35. The system of claim 31, wherein the processor is configured to determine the third gain by comparing the first measurement of the intensity relative to a dynamic range of the detector with the second measurement of the intensity relative to the dynamic range of the detector.
  36. The system of claim 31, wherein the processor is configured to determine the third gain by determining whether the first measurement of the intensity or the second measurement of the intensity falls out of a dynamic range of the detector.
  37. The system of claim 31, wherein the processor is further configured to generate an image of the target scene, the image comprising the measurement of the characteristic.
  38. The system of claim 31, wherein the first measurement of the intensity and the second measurement of the intensity are digital signals.
  39. The system of claim 31, wherein the light is a laser.
  40. The system of claim 31, wherein the light is infrared.
PCT/CN2018/075180 2018-02-03 2018-02-03 Methods and systems with dynamic gain determination WO2019148475A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/CN2018/075180 WO2019148475A1 (en) 2018-02-03 2018-02-03 Methods and systems with dynamic gain determination
TW108104244A TWI791758B (en) 2018-02-03 2019-02-01 Methods and systems with dynamic gain determination

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2018/075180 WO2019148475A1 (en) 2018-02-03 2018-02-03 Methods and systems with dynamic gain determination

Publications (1)

Publication Number Publication Date
WO2019148475A1 true WO2019148475A1 (en) 2019-08-08

Family

ID=67478578

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2018/075180 WO2019148475A1 (en) 2018-02-03 2018-02-03 Methods and systems with dynamic gain determination

Country Status (2)

Country Link
TW (1) TWI791758B (en)
WO (1) WO2019148475A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102316282A (en) * 2011-09-20 2012-01-11 中国科学院理化技术研究所 Image noise reducing device based on optics dolby
CN102735349A (en) * 2011-04-08 2012-10-17 中国科学院光电研究院 Apparatus for measuring multiple parameters of laser
CN103760567A (en) * 2014-01-27 2014-04-30 中国科学院半导体研究所 Passive imaging system with distance measuring function and distance measuring method thereof
WO2017219223A1 (en) * 2016-06-21 2017-12-28 Shenzhen Genorivision Technology Co. Ltd. An image sensor with large dynamic range

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006029025A1 (en) * 2006-06-14 2007-12-27 Iris-Gmbh Infrared & Intelligent Sensors Reflective object distance determining device, has two integrators connected with photoelectric unit and control input, where photoelectric unit is rectangle or square shape and exhibits specific side length
US10184835B2 (en) * 2015-09-23 2019-01-22 Agilent Technologies, Inc. High dynamic range infrared imaging spectroscopy
TWI571649B (en) * 2015-12-03 2017-02-21 財團法人金屬工業研究發展中心 A scanning device and method for establishing an outline image of an object
CN106324609B (en) * 2016-08-30 2019-09-03 北京小米移动软件有限公司 Laser ranging sensor LDS, robot and distance measuring method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102735349A (en) * 2011-04-08 2012-10-17 中国科学院光电研究院 Apparatus for measuring multiple parameters of laser
CN102316282A (en) * 2011-09-20 2012-01-11 中国科学院理化技术研究所 Image noise reducing device based on optics dolby
CN103760567A (en) * 2014-01-27 2014-04-30 中国科学院半导体研究所 Passive imaging system with distance measuring function and distance measuring method thereof
WO2017219223A1 (en) * 2016-06-21 2017-12-28 Shenzhen Genorivision Technology Co. Ltd. An image sensor with large dynamic range

Also Published As

Publication number Publication date
TW201935036A (en) 2019-09-01
TWI791758B (en) 2023-02-11

Similar Documents

Publication Publication Date Title
KR101937777B1 (en) Lidar device and method for measuring distance using the same
CN108781116B (en) Power adjustment method and laser measurement device
WO2020258933A1 (en) Lidarreceiving apparatus, lidar system and laser ranging method
CN109870678B (en) Laser radar transmitting power and echo gain automatic adjusting method and adjusting device
KR102013785B1 (en) Lidar system
US11598847B2 (en) LiDAR apparatus and method of operating the same
KR102506438B1 (en) Distance measuring device and method for measuring distance by using thereof
JP7131180B2 (en) Ranging device, ranging method, program, moving body
US11333765B2 (en) Distance measuring device and method
WO2020191727A1 (en) Radar power control method and device
JP2016014535A (en) Distance measuring system
US11448738B2 (en) Light detection and ranging signal correction methods and systems
US11624811B2 (en) Apparatus and method for increasing LIDAR sensing distance
WO2019148475A1 (en) Methods and systems with dynamic gain determination
US11061138B2 (en) Distance measuring device and method of measuring distance by using the same
KR101866764B1 (en) Range Image Sensor comprised of Combined Pixel
JPWO2020263735A5 (en)
US20220155442A1 (en) Light detection device, lidar device including the same, and method of measuring distance
KR102390231B1 (en) Scanning lidar and method for controlling fov of the scanning lidar
JP2015200566A (en) Distance metrology device, distance metrology method and distance metrology program
EP3640669B1 (en) Solid-state optical receiver driver system and method for testing a solid-state optical receiver driver system
CN113841064A (en) Method for operating a photodiode
EP4206727A1 (en) Lidar device and operating method thereof
EP3985413A1 (en) Distance measuring device and method for measuring distance by using the same
US20220003851A1 (en) Dynamic receiver gain control for lidar system

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18903909

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 11/01/2021)

122 Ep: pct application non-entry in european phase

Ref document number: 18903909

Country of ref document: EP

Kind code of ref document: A1