Particle sensor including at least two laser doppler sensors

Patent metadata

Field	Value
Publication number	US-2020056972-A1
Application number	US-201716348332-A
Country	US
Kind code	A1
Filing date	Sep 12, 2017
Priority date	Nov 9, 2016
Publication date	Feb 20, 2020
Grant date	—

Abstract

A particle sensor that includes a first laser Doppler sensor and at least a second laser Doppler sensor, as well as a control unit that is configured to carry out self-interference measurements with the first laser Doppler sensor and simultaneously with at least the second laser Doppler sensor.

First claim

1 .- 10 . (canceled)

11 . A particle sensor, comprising:
a first laser Doppler sensor; and at least a second laser Doppler sensor; and a control unit configured to carry out a self-interference measurement with the first laser Doppler sensor and simultaneously with at least the second laser Doppler sensor.

12 . The particle sensor as recited in claim 11 , wherein:
the first laser Doppler sensor includes a first optical system with a first external focal point and a first detection volume, and the second laser Doppler sensor includes a second optical system with a second external focal point and a second detection volume.

13 . The particle sensor as recited in claim 12 , wherein the first detection volume and the second detection volume overlap.

14 . The particle sensor as recited in claim 11 , wherein:
the first laser Doppler sensor has a first polarization direction, and the second laser Doppler sensor has a second polarization direction that is different from the first polarization direction.

15 . The particle sensor as recited in claim 12 , wherein the first detection volume and the second detection volume do not overlap.

16 . The particle sensor as recited in claim 12 , wherein:
at least one of the first laser Doppler sensor and the second laser Doppler sensor includes a movable beam-deflecting element as a result of which at least one of the first detection volume and the second detection volume is placeable at at least one location.

17 . The particle sensor as recited in claim 16 , wherein the movable beam-deflecting element is a micromirror.

18 . The particle sensor as recited in claim 12 , wherein at least one of the first optical system includes a variably locatable first external focal point and the second optical system includes a variably locatable second external focal point, and wherein as a result of which at least one of the first detection volume and the second detection volume is determinable at various locations.

19 . The particle sensor as recited in claim 11 , wherein:
at least one of the first laser Doppler sensor and the first optical system is optimized with regard to a first detection efficiency for a first particle size range, and at least one of the second laser Doppler sensor and the second optical system is optimized with regard to a second detection efficiency for a second particle size range that is different from the first particle size range.

20 . The particle sensor as recited in claim 11 , wherein:
the control unit checks a plausibility of a sensor signal of the particle sensor and is configured for checking time-resolved signal amplitudes of the first laser Doppler sensor and at least the second laser Doppler sensor with regard to a likelihood that a single particle has generated a signal for the first laser Doppler sensor and the second laser Doppler sensor one of in succession and at the same time.

21 . The particle sensor as recited in claim 11 , the first laser Doppler sensor, the second laser Doppler sensor, and further laser Doppler sensors are arranged in one of a 2D array and a 3D array for monitoring one of a surface area and a spatial area.

Assignees

• Bosch Gmbh Robert

Inventors

• Jatekos Balazs
• Scholten Dick
• Ramsteiner Ingo
• Kakonyi Robert
• Pinter Stefan

Classifications

• G01S7/499

  using polarisation effects · CPC title

• G01S17/58

  Velocity or trajectory determination systems; Sense-of-movement determination systems · CPC title

• G01N15/1456

  without spatial resolution of the texture or inner structure of the particle, e.g. processing of pulse signals · CPC title

• G01N2015/1454

  using phase shift or interference, e.g. for improving contrast · CPC title

• G01N15/0211 Primary

  Investigating a scatter or diffraction pattern · CPC title