CA2304083A1 - Method for measuring the distance to at least one target - Google Patents
Method for measuring the distance to at least one target Download PDFInfo
- Publication number
- CA2304083A1 CA2304083A1 CA002304083A CA2304083A CA2304083A1 CA 2304083 A1 CA2304083 A1 CA 2304083A1 CA 002304083 A CA002304083 A CA 002304083A CA 2304083 A CA2304083 A CA 2304083A CA 2304083 A1 CA2304083 A1 CA 2304083A1
- Authority
- CA
- Canada
- Prior art keywords
- function
- time
- input signal
- values
- determined
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
Classifications
-
- 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
- G01S7/497—Means for monitoring or calibrating
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Electromagnetism (AREA)
- Optical Radar Systems And Details Thereof (AREA)
- Radar Systems Or Details Thereof (AREA)
- Measurement Of Optical Distance (AREA)
Abstract
To measure the distance to targets, local maxima exceeding a threshold (.epsilon.) and being associated with a correlation function (f) are determined, the reference values of which are obtained from scaler products of a received signal (e), produced by reflections of an optical pulse by the targets, and a number of comparison functions, copies of a reference function (r) which are shifted as a function of time, and the transit times of the reflections are derived from the time-related shifts of the corresponding comparison functions. By interpolation with respect to the time-related shifts or optimization thereof, for example by adjusting them so that the orthogonal distance of the received signal (e) from the vector space which is spanned by the corresponding comparison functions is a minimum, the transit times can be determined even more accurately.
Claims (20)
1. A method for measuring the distance to at least one target, in which an optical pulse is sent by a transmitter toward said target, reflections of the at least one pulse are picked up by a receiver and converted into a received signal (e) and stored and in each case a transit time is determined from a reception time of the input signal and the distance is calculated therefrom, wherein, to determine the at least one reception time, the input signal (e) is compared with comparison functions which are copies, shifted by various time intervals, of a previously determined and stored reference function (r), and the reception times are at least approximately determined from the time intervals which correspond to the most similar comparison function.
2. The method as claimed in claim 1, wherein the at least approximate determination of the at least one reception time is based on a set of comparison functions which correspond to predetermined fixed time intervals.
3. The method as claimed in claim 2, wherein the predetermined fixed time intervals are integral multiples of a fixed basic interval.
4. The method as claimed in claim 2 or 3, wherein only those comparison functions where in each case the similarity function (f) representing a measure of similarity with the received signal (e) forms a local maximum which exceeds a specific threshold (.epsilon.) are used.
5. The method as claimed in claim 4, wherein the similarity function used is a correlation function (f).
6. The method as claimed in claim 5, wherein the function values of the correlation function are calculated in each case as the scaler product of the received signal (e) and one of the comparison functions.
7. The method as claimed in any of claims 2 to 6, wherein exact reception times are determined starting from the approximately determined reception times, by interpolation between the time intervals.
8. The method as claimed in any of claims 4 to 6 and claim 7, wherein the interpolation is effected by determining t:he local maximum of the correlation function (f) expanded between reference values to give a continuous function.
9. The method as claimed in claim 7 or 8, wherein the interpolation is carried out at least in part by minimizing the distance of the received signal (e) from a vector space which is spanned by the comparison functions corresponding to the reception times, starting from the vector space which is spanned by the comparison functions which correspond to the approximately determined reception times.
10. The method as claimed in any of claims 1 to 9, wherein the received signal (e) is scanned at times which in each case follow one another at intervals of a fixed scanning increment (.DELTA.).
11. The method as claimed in any of claims 1 to 10, wherein the reference function (r) is determined at a number of points which follow one another at intervals of reference increments (.delta.).
12. The method as claimed in claims 10 and 11, wherein the reference increment (.delta.) corresponds in each case to the scanning increment (.DELTA.) divided by an integer >1.
13. The method as claimed in any of claims 1 to 12, wherein, to determine the reference function (r), at least one optical pulse is sent toward a reference target (10), and the corresponding reference input signal is scanned for determining the reference values of the reference function (r).
14. The method as claimed in claim 13, wherein, to improve the resolution as a function of time, the reference input signal is shifted as a function of time by various delay values.
15. The method as claimed in claim 14, wherein the shifting of the reference input signal as a function of time is effected by delaying the emission of the optical pulse by the transmitter (6) or of the reference input signal.
16. The method as claimed in claim 14, wherein the shifting of the reference input signal as a function of time is effected by changing the distance to the reference target (10).
17. The method as claimed in any of claims 13 to 16, wherein, to improve the signal-to-noise ratio, the emission of the optical pulse and the scanning of the reference input signal are repeated and, for the formation of the reference values of the reference function (r), the scanning values corresponding to identical transit times are summed or averaged.
18. The method as claimed in any of claims 10 to 17, wherein, starting from reference values, the reference function (r) is expanded by interpolation to give a continuous function preferably continuously differentiable at least once.
19. The method as claimed in any of claims 14 to 17, wherein a formulation according to which the reference function (r) can be fixed by a finite number of parameters and the parameters are determined from a comparison of the reference input signal with copies of the reference function which are shifted as a function of time by the delay values is postulated for the reference function (r).
20. The method as claimed in claim 19, wherein, to determine the parameters, the distance of the reference received signal from a superposition of the copies of the reference function (r) which are shifted as a function of time by the delay values is minimized.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP99106840.4 | 1999-04-06 | ||
EP99106840A EP1043603A1 (en) | 1999-04-06 | 1999-04-06 | Method for detecting the distance of at least one target |
US09/542,879 US6516286B1 (en) | 1999-04-06 | 2000-04-04 | Method for measuring the distance to at least one target |
Publications (2)
Publication Number | Publication Date |
---|---|
CA2304083A1 true CA2304083A1 (en) | 2000-10-06 |
CA2304083C CA2304083C (en) | 2013-05-28 |
Family
ID=26152957
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA2304083A Expired - Lifetime CA2304083C (en) | 1999-04-06 | 2000-04-05 | Method for measuring the distance to at least one target |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP1043603A1 (en) |
JP (1) | JP4843128B2 (en) |
AT (1) | ATE232306T1 (en) |
CA (1) | CA2304083C (en) |
DE (1) | DE50001197D1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10782391B2 (en) | 2015-08-12 | 2020-09-22 | Trw Limited | Processing received radiation reflected from a target |
US11169255B2 (en) | 2016-12-08 | 2021-11-09 | Trw Limited | Processing a signal representative of at least one physical property of a physical system |
US11703591B2 (en) | 2017-12-21 | 2023-07-18 | Leica Geosystems Ag | Measuring device with measurement beam homogenization |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2014174069A (en) * | 2013-03-12 | 2014-09-22 | Mitsubishi Electric Corp | Laser range finding device |
EP2789972B1 (en) | 2013-04-12 | 2017-08-16 | Hexagon Technology Center GmbH | Measuring device with deformable optical element |
JPWO2015098469A1 (en) * | 2013-12-27 | 2017-03-23 | 株式会社リコー | Ranging device, electronic equipment, ranging method, ranging program |
EP3783305B1 (en) | 2019-08-21 | 2022-03-23 | Leica Geosystems AG | Drive system in a geodetic measurement instrument |
EP3812701B1 (en) | 2019-10-23 | 2022-08-24 | Hexagon Technology Center GmbH | Online leveling calibration of a geodetic instrument |
EP4354084A1 (en) | 2022-10-10 | 2024-04-17 | Hexagon Technology Center GmbH | In-the-field leveling calibration of a surveying instrument |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5480771A (en) * | 1977-12-10 | 1979-06-27 | Tech Res & Dev Inst Of Japan Def Agency | Range finder |
JPS5846397A (en) * | 1981-09-15 | 1983-03-17 | アンリツ株式会社 | Apparatus for measuring similarity of waveforms of two signals |
JPS6252478A (en) * | 1985-08-31 | 1987-03-07 | Nec Corp | Acoustic depth sounder |
JPS641993A (en) * | 1987-06-23 | 1989-01-06 | Nec Corp | Echo sounder |
JPS6443781A (en) * | 1987-08-11 | 1989-02-16 | Mitsubishi Electric Corp | Radar signal processor |
US4787252A (en) * | 1987-09-30 | 1988-11-29 | Panametrics, Inc. | Differential correlation analyzer |
JPH06100654B2 (en) * | 1990-03-28 | 1994-12-12 | 運輸省港湾技術研究所長 | Ultrasonic rangefinder |
JP3068674B2 (en) * | 1991-07-29 | 2000-07-24 | 株式会社トキメック | Ultrasonic transducer |
DE4128560A1 (en) * | 1991-08-28 | 1993-03-04 | Telefunken Systemtechnik | METHOD FOR DETERMINING THE SPEED OF A MOVING OBJECT BY MEANS OF AT LEAST ONE DOPPLER RADAR SENSOR, AND DEVICE FOR CARRYING OUT THE METHOD |
JPH05100022A (en) * | 1991-10-11 | 1993-04-23 | Mitsubishi Heavy Ind Ltd | Sonar signal processing device |
JPH05273272A (en) * | 1992-01-16 | 1993-10-22 | Hamamatsu Photonics Kk | Timing-difference measuring system |
DE19517001A1 (en) * | 1995-05-09 | 1996-11-14 | Sick Optik Elektronik Erwin | Method and device for determining the light propagation time over a measuring section arranged between a measuring device and a reflecting object |
DE19611233A1 (en) * | 1996-03-21 | 1997-09-25 | Siemens Ag | Procedure for measuring the transit time of an electrical, electromagnetic or acoustic signal |
JP3641870B2 (en) * | 1996-03-28 | 2005-04-27 | 日産自動車株式会社 | Random modulation radar equipment |
DE19701803A1 (en) * | 1997-01-20 | 1998-10-01 | Sick Ag | Light sensor with light transit time evaluation |
-
1999
- 1999-04-06 EP EP99106840A patent/EP1043603A1/en not_active Withdrawn
-
2000
- 2000-04-04 DE DE50001197T patent/DE50001197D1/en not_active Expired - Lifetime
- 2000-04-04 AT AT00107292T patent/ATE232306T1/en active
- 2000-04-05 CA CA2304083A patent/CA2304083C/en not_active Expired - Lifetime
- 2000-04-06 JP JP2000105448A patent/JP4843128B2/en not_active Expired - Lifetime
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10782391B2 (en) | 2015-08-12 | 2020-09-22 | Trw Limited | Processing received radiation reflected from a target |
US11169255B2 (en) | 2016-12-08 | 2021-11-09 | Trw Limited | Processing a signal representative of at least one physical property of a physical system |
US11703591B2 (en) | 2017-12-21 | 2023-07-18 | Leica Geosystems Ag | Measuring device with measurement beam homogenization |
Also Published As
Publication number | Publication date |
---|---|
ATE232306T1 (en) | 2003-02-15 |
EP1043603A1 (en) | 2000-10-11 |
JP2000304862A (en) | 2000-11-02 |
JP4843128B2 (en) | 2011-12-21 |
DE50001197D1 (en) | 2003-03-13 |
CA2304083C (en) | 2013-05-28 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
MKEX | Expiry |
Effective date: 20200405 |