Optical Distance Measurement Device with Calibration Device to take Cross-Talk into Account

• US 20150124241A1
• Filed: 03/19/2013
• Published: 05/07/2015
• Est. Priority Date: 05/18/2012
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Eisele, Andreas, Schmidtke, Bernd
• Granted Patent: US 9,791,559 B2
• Time in Patent Office: Days
• US Class Current: 356/5.01
• CPC Class Codes: G01C 25/00 Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass testing, calibrating or compensating compasses G01C17/38
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/36 with phase comparison between the received signal and the contemporaneously transmitted signal
• CPC Class Codes: G01S 7/4911 Transmitters
• CPC Class Codes: G01S 7/4913 Circuits for detection, sampling, integration or read-out
• CPC Class Codes: G01S 7/4918 Controlling received signal intensity, gain or exposure of sensor
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating

Abstract

A measurement device for measuring an optical distance of an object includes an emission device configured to emit a first signal towards the object. The measurement device further includes a modulator device configured to modulate the first signal and a reception device configured to detect a second signal. The measurement device also includes an analysis device configured to receive and analyze the second signal. The measurement device further includes a calibration device configured to calibrate the measurement device with the modulator device turned on and with the emission device operated below a pre-definable power threshold value.

Claims

1. A measurement device for measuring an optical distance of an object, the measurement device comprising:

an emission device configured to emit a first signal towards the object;

a modulator device configured to modulate the first signal;

a reception device configured to detect a second signal;

an analysis device configured to receive and analyze the second signal; and

a calibration device configured to calibrate the measurement device with the modulator device turned on and with the emission device operated below a pre-definable power threshold value.

2. The measurement device as claimed in claim 1, wherein the calibration device is configured to calibrate the measurement device with reference to a crosstalk between at least one of (i) the reception device and the modulator device and (ii) the analysis device and the modulator device.

3. The measurement device as claimed in claim 1, wherein the second signal includes a calibration second signal and a distance measuring second signal, and the calibration second signal during the calibration measurement has an optical background radiation returning from the object, and the distance measuring second signal during the distance measurement has the optical background radiation and a measurement radiation returning from the object.

4. The measurement device as claimed in claim 1, wherein the reception device and the analysis device are integrally embodied.

5. The measurement device as claimed in claim 1, wherein the reception device has an avalanche photodiode or a single photon avalanche diode.

6. The measurement device as claimed in claim 1, wherein the emission device is a laser and the laser is operated below a laser threshold during the calibration of the measurement device.

7. The measurement device as claimed in claim 1, wherein the second signal includes a calibration second signal and a distance measuring second signal, and the calibration device is configured to calibrate the measurement device such that the distance measuring second signal detected by the reception device during the distance measurement is divided by the calibration second signal detected during the calibration measurement.

8. A method for calibrating a measurement device, the method comprising:

emitting a first signal using an emission device towards an object using a power value below a pre-definable power threshold value;

modulating the first signal of the emission device using a modulator device;

detecting a second signal using a reception device;

receiving and analyzing the second signal using an analysis device; and

calibrating the measurement device using a calibration device based on the second signal,

wherein the measurement device includes the emission device, the modulator device, the reception device, the analysis device, and the calibration device.