Distributed localization systems and methods and self-localizing apparatus

• US 9,945,929 B2
• Filed: 06/03/2016
• Issued: 04/17/2018
• Est. Priority Date: 03/07/2015
• Status: Active Grant

• Current Assignee: Verity AG
• Original Assignee: Verity Studios AG
• Inventors: Hehn, Markus, Waibel, Markus, D'Andrea, Raffaello
• Primary Examiner(s): CAI, WAYNE HUU
• Application Number:
  US15/173,556
• Publication Number:
  US 20170003374A1
• Time in Patent Office: 683 Days
• CPC Class Codes: G01S 1/024 of beacon transmitters
• CPC Class Codes: G01S 1/20 using a comparison of transit time of synchronised signals transmitted from non-directional antennas or antenna systems spaced apart, i.e. path-difference systems
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G05D 1/101 specially adapted for aircraft
• CPC Class Codes: H04B 1/7163 using impulse radio
• CPC Class Codes: H04W 4/026 using orientation information, e.g. compass
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A self-localizing apparatus uses timestampable signals transmitted by transceivers that are a part of a distributed localization system to compute its position relative to the transceivers. Transceivers and self-localizing apparatuses are arranged for highly accurate timestamping using digital and analog reception and transmission electronics as well as one or more highly accurate clocks, compensation units, localization units, position calibration units, scheduling units, or synchronization units. Transceivers and self-localizing apparatuses are further arranged to allow full scalability in the number of self-localizing apparatuses and to allow robust self-localization with latencies and update rates useful for high performance applications such as autonomous mobile robot control.

Claims

1. A localization system, comprising:

three ultra wideband (UWB) transceivers, each operable to emit an UWB signal and each comprising;

a transceiver antenna;

a transceiver clock;

analog transmission electronics; and

digital transmission electronics operationally coupled to the transceiver clock and the analog transmission electronics and operable to emit the UWB signal at a scheduled transmission time with reference to the transceiver clock;

a first self-localizing apparatus operable to receive the UWB signals, comprising;

a first apparatus antenna operable to receive the UWB signals, wherein the first apparatus antenna is operable to receive;

a first UWB signal from a first of the three UWB transceivers;

a second UWB signal from a second of the three UWB transceivers;

a third UWB signal from a third of the three UWB transceivers;

a first apparatus clock;

first apparatus analog reception electronics;

first apparatus digital reception electronics operationally coupled to the first apparatus clock and the first apparatus analog reception electronics and operable to timestamp the received first, second, and third UWB signals with reference to the first apparatus clock; and

a first localization unit operationally coupled to the first apparatus digital reception electronics and operable to compute a relative location of the first self-localizing apparatus to the three UWB transceivers based on the timestamps of the received first, second, and third UWB signals; and

a second self-localizing apparatus operable to receive the UWB signals, comprising;

a second apparatus antenna operable to receive the UWB signals, wherein the second apparatus antenna is operable to receive;

the first UWB signal from the first of the three UWB transceivers;

the second UWB signal from the second of the three UWB transceivers;

the third UWB signal from the third of the three UWB transceivers;

a second apparatus clock;

second apparatus analog reception electronics;

second apparatus digital reception electronics operationally coupled to the second apparatus clock and the second apparatus analog reception electronics and operable to timestamp the received first, second, and third UWB signals with reference to the second apparatus clock; and

a second localization unit operationally coupled to the second apparatus digital reception electronics and operable to compute a relative location of the second self-localizing apparatus to the three UWB transceivers based on the timestamps of the received first, second, and third UWB signals.

2. The system of claim 1, further comprising:

a scheduling unit operationally coupled to the three UWB transceivers and operable to schedule the emission of the UWB signals from the three UWB transceivers.

3. The system of claim 2, further comprising:

a synchronization unit operable to compute a correction for at least one of a clock offset and a clock rate between a first and a second of the transceiver clocks, and wherein at least two of the transceiver clocks are each structured to have an Allan variance of at most (1×

10<sup>−

8</sup>)² for averaging intervals between 5 ms and 10 ms and wherein the relative location computed by the first localization unit is computed with an accuracy of 1 m or better.

4. The system of claim 1, further comprising:

a compensation unit; and

a memory unit,

wherein the first localization unit is further operable to compute the relative location based on;

a compensation computed by the compensation unit; and

data provided by the memory unit.

5. The system of claim 1, wherein the first self-localizing apparatus further comprises:

a sensor structured to detect an absence of motion,

wherein the first localization unit is further operable to compute the relative location based on the absence of motion.

6. The system of claim 1, wherein each of the three UWB transceivers further comprises:

a sensor structured to detect a disturbance to the transceiver'"'"'s position or orientation.

7. The system of claim 1, wherein the first self-localizing apparatus further comprises:

a compensation unit operationally coupled to the apparatus digital reception electronics and operable to compute one of;

a compensation for a time difference of arrival between a first UWB signal traveling from a first UWB transceiver to the first self-localizing apparatus and a second UWB signal traveling from a second, different UWB transceiver to the first self-localizing apparatus; and

a compensation for the time stamp of a first UWB signal traveling from the first UWB transceiver to the first self-localizing apparatus.

8. The system of claim 7, wherein the compensation unit is further operable to compute the compensation by implicitly or explicitly accounting for timing errors introduced by one or more of:

the first apparatus antenna;

the first apparatus analog reception electronics;

the first apparatus digital reception electronics;

motion of the first self-localizing apparatus;

the transceiver antenna of the first UWB transceiver;

the analog transmission electronics of the first UWB transceiver;

the digital transmission electronics of the first UWB transceiver;

the transceiver antenna of the second UWB transceiver;

the analog transmission electronics of the second UWB transceiver; and

the digital transmission electronics of the second UWB transceiver.

9. The system of claim 8, further comprising:

a mobile robot physically and operationally coupled to the first self-localizing apparatus,

wherein each of the three UWB transceivers further comprises;

transceiver analog reception electronics;

transceiver digital reception electronics operationally coupled to the transceiver analog reception electronics and the transceiver clock;

memory;

a transceiver global property sensor operable to provide transceiver data representative of a global property;

a sensor structured to detect at least one the transceiver'"'"'s orientation and a disturbance to the transceiver'"'"'s position or orientation;

a synchronization unit operationally coupled to the transceiver clock and operable to compute a clock correction for at least one of an offset of the transceiver clock and a rate of the transceiver clock; and

a scheduling unit operationally coupled to the memory, the digital transmission electronics, the transceiver digital reception electronics, and the synchronization unit, and operable to schedule the transmission time of the UWB signal,

wherein the first self-localizing apparatus further comprises;

an apparatus global property sensor operable to provide apparatus data representative of the global property;

an apparatus orientation sensor operable to provide data representative of orientation information of the first self-localizing apparatus;

a motion sensor operable to provide data representative of a motion of the first self-localizing apparatus, wherein the first localization unit is operable to compute the relative location further based on the data representative of the global property of at least one of the three UWB transceivers, the data representative of the three UWB transceivers'"'"' orientations, the apparatus data representative of the global property, and the data representative of the motion of the first self-localizing apparatus;

an onboard actuator operable to influence the first self-localizing apparatus'"'"' motion; and

a control unit operable to produce a control signal for the onboard actuator based on the relative location.

10. The system of claim 7, wherein the compensation unit is operable to compute the compensation based on signal gain of the first self-localization apparatus.

11. The system of claim 7, wherein the compensation unit is operable to compute the compensation based on an obstacle affecting UWB signals received from the first UWB transceiver.

12. The system of claim 7, wherein the compensation unit is operable to compute the compensation based on reception angle of the first UWB signal.

13. The system of claim 7, wherein the compensation unit is operable to compute the compensation based on received signal strength of the first UWB signal.

14. The system of claim 1, further comprising:

a synchronization unit operationally coupled to a first clock of the three transceiver clocks and the first apparatus clock and operable to synchronize at least one of;

an offset of the first clock; and

a rate of the first clock,

based on a second, different clock of the three transceiver clocks and the first apparatus clock.

15. The system of claim 1, wherein the localization system is operable in an indoor environment and wherein the first localization unit is operable to compute the relative location of the first self-localizing apparatus in the indoor environment with a precision of at least 20 centimeters and wherein the three UWB transceivers are operationally spaced apart from each other 25 meters or less in the indoor environment.

16. The system of claim 1, wherein the relative locations of the three UWB transceivers are known in a three-dimensional coordinate space and wherein the computed relative location of the first self-localizing apparatus comprises a location in the three-dimensional coordinate space.

17. The system of claim 1, wherein the transceiver antenna of a first UWB transceiver of the three UWB transceivers is operable to receive UWB signals of a second UWB transceiver of the three UWB transceivers and wherein the first UWB transceiver comprises:

transceiver analog reception electronics; and

transceiver digital reception electronics operationally coupled to the transceiver clock of the first UWB transceiver and the transceiver analog reception electronics and operable to timestamp the received UWB signals of the second UWB transceiver with reference to the transceiver clock of the first UWB transceiver.

18. The system of claim 17, wherein the first UWB transceiver further comprises a synchronization unit operable to compute a correction to the transceiver clock of the first UWB transceiver based on the timestamps of the received UWB signals of the second UWB transceiver to obtain a common, synchronized reference time between the first UWB transceiver and the second UWB transceiver.

19. The system of claim 18, wherein the synchronization unit is further operable to compute the correction based on transmission times of the received UWB signals of the second UWB transceiver.

20. The system of claim 1, wherein the first self-localizing apparatus further comprises a synchronization unit operable to compute a clock correction for the first apparatus clock based on the timestamps of the received UWB signals from at least two of the three UWB transceivers.

21. A localization system, comprising:

three ultra wideband (UWB) transceivers, each operable to emit an UWB signal and each comprising;

a transceiver antenna;

a transceiver clock;

analog transmission electronics; and

digital transmission electronics operationally coupled to the transceiver clock and the analog transmission electronics and operable to emit the UWB signal at a scheduled transmission time with reference to the transceiver clock; and

a mobile robot comprising;

a self-localizing apparatus operable to receive the UWB signals, comprising;

an apparatus antenna operable to receive the UWB signals;

an apparatus clock;

apparatus analog reception electronics;

apparatus digital reception electronics operationally coupled to the apparatus clock and the apparatus analog reception electronics and operable to timestamp the received UWB signals with reference to the apparatus clock; and

a localization unit operationally coupled to the apparatus digital reception electronics and operable to compute a relative location of the self-localizing apparatus to the three UWB transceivers based on the timestamps of the received UWB signals;

an onboard actuator operable to control the movement of the mobile robot through space; and

a control unit operable to produce a control signal for the onboard actuator based on the relative location.

22. A localization system, comprising:

three ultra wideband (UWB) transceivers, each operable to emit an UWB signal and each comprising;

a transceiver antenna;

a transceiver clock;

analog transmission electronics; and

digital transmission electronics operationally coupled to the transceiver clock and the analog transmission electronics and operable to emit the UWB signal at a scheduled transmission time with reference to the transceiver clock; and

a self-localizing apparatus operable to receive the UWB signals, comprising;

an apparatus antenna operable to receive the UWB signals;

an apparatus clock;

apparatus analog reception electronics;

apparatus digital reception electronics operationally coupled to the apparatus clock and the apparatus analog reception electronics and operable to timestamp the received UWB signals with reference to the apparatus clock;

a localization unit operationally coupled to the apparatus digital reception electronics and operable to compute a relative location of the self-localizing apparatus to the three UWB transceivers based on the timestamps of the received UWB signals;

an onboard actuator operable to influence a motion of the self-localizing apparatus, wherein the self-localizing apparatus is operable to move the self-localizing apparatus in response to a disturbance to the relative location and wherein the movement reduces the disturbance in less than 1 second; and

a control unit operable to produce a control signal for the onboard actuator based on the relative location.

23. A localization system, comprising:

three ultra wideband (UWB) transceivers, each operable to emit an UWB signal and each comprising;

a transceiver antenna;

a transceiver clock;

analog transmission electronics; and

digital transmission electronics operationally coupled to the transceiver clock and the analog transmission electronics and operable to emit the UWB signal at a scheduled transmission time with reference to the transceiver clock; and

a self-localizing apparatus operable to receive the UWB signals, comprising;

an apparatus antenna operable to receive the UWB signals;

an apparatus clock;

apparatus analog reception electronics;

apparatus digital reception electronics operationally coupled to the apparatus clock and the apparatus analog reception electronics and operable to timestamp the received UWB signals with reference to the apparatus clock; and

a localization unit operationally coupled to the apparatus digital reception electronics and operable to compute a relative location of the self-localizing apparatus to the three UWB transceivers based on the timestamps of the received UWB signals, wherein the self-localizing apparatus is operable to receive two of the UWB signals within a time window of 10 seconds and wherein the time difference between the time stamps of the two UWB signals is within 3 nanoseconds of the time difference between their reception times at the apparatus antenna with reference to the apparatus clock.

24. A localization system, comprising:

three ultra wideband (UWB) transceivers, each operable to emit an UWB signal and each comprising;

a transceiver antenna;

a transceiver clock;

analog transmission electronics; and

digital transmission electronics operationally coupled to the transceiver clock and the analog transmission electronics and operable to emit the UWB signal at a scheduled transmission time with reference to the transceiver clock; and

a self-localizing apparatus operable to receive the UWB signals, comprising;

an apparatus antenna operable to receive the UWB signals;

an apparatus clock;

apparatus analog reception electronics;

apparatus digital reception electronics operationally coupled to the apparatus clock and the apparatus analog reception electronics and operable to timestamp the received UWB signals with reference to the apparatus clock; and

a localization unit operationally coupled to the apparatus digital reception electronics and operable to compute a relative location of the self-localizing apparatus to the three UWB transceivers based on the timestamps of the received UWB signals, wherein a first clock and a second, different clock of the three transceiver clocks and the apparatus clock are each structured to have an Allan variance of at most (1×

10<sup>−

8</sup>)² for averaging intervals between 5 ms and 10 ms.

25. A localization system, comprising:

a first ultra wideband (UWB) transceiver, a second UWB transceiver, and a third UWB transceiver, each operable to emit an UWB signal, wherein;

the first UWB transceiver comprises;

a first transceiver antenna operable to receive the UWB signal emitted by the second UWB transceiver and the UWB signal emitted by the third UWB transceiver;

a first transceiver clock;

first transceiver analog reception electronics;

first transceiver digital reception electronics operationally coupled to the first transceiver clock and the first transceiver analog reception electronics and operable to timestamp the UWB signals received from the second UWB transceiver and the third UWB transceiver with reference to the first transceiver clock;

a first synchronization unit operable to compute a clock correction based on the timestamps of the UWB signals received from the second UWB transceiver and the third UWB transceiver;

first analog transmission electronics; and

first digital transmission electronics operationally coupled to the first transceiver clock and the first analog transmission electronics and operable to emit the UWB signal at a scheduled transmission time with reference to the first transceiver clock;

the second UWB transceiver comprises;

a second transceiver antenna operable to receive the UWB signal emitted by the first UWB transceiver and the UWB signal emitted by the third UWB transceiver;

a second transceiver clock;

second transceiver analog reception electronics;

second transceiver digital reception electronics operationally coupled to the second transceiver clock and the second transceiver analog reception electronics and operable to timestamp the UWB signals received from the first UWB transceiver and the third UWB transceiver with reference to the second transceiver clock;

a second synchronization unit operable to compute a clock correction based on the timestamps of the UWB signals received from the first UWB transceiver and the third UWB transceiver;

second analog transmission electronics; and

second digital transmission electronics operationally coupled to the second transceiver clock and the second analog transmission electronics and operable to emit the UWB signal at a scheduled transmission time with reference to the second transceiver clock;

the third UWB transceiver comprises;

a third transceiver antenna operable to receive the UWB signal emitted by the first UWB transceiver and the UWB signal emitted by the second UWB transceiver;

a third transceiver clock;

third transceiver analog reception electronics;

third transceiver digital reception electronics operationally coupled to the third transceiver clock and the third transceiver analog reception electronics and operable to timestamp the UWB signals received from the first UWB transceiver and the second UWB transceiver with reference to the third transceiver clock;

a third synchronization unit operable to compute a clock correction based on the timestamps of the UWB signals received from the first UWB transceiver and the second UWB transceiver;

third analog transmission electronics; and

third digital transmission electronics operationally coupled to the third transceiver clock and the third analog transmission electronics and operable to emit the UWB signal at a scheduled transmission time with reference to the third transceiver clock; and

the first synchronization unit, the second synchronization unit, and the third synchronization unit compute their respective clock corrections in order for the first UWB transceiver, the second UWB transceiver, and the third UWB transceiver to obtain a common, synchronized reference time; and

a self-localizing apparatus operable to receive UWB signals from the first ultra wideband (UWB) transceiver, the second UWB transceiver, and the third UWB transceiver, comprising;

an apparatus antenna operable to receive the UWB signals;

an apparatus clock;

apparatus analog reception electronics;

apparatus digital reception electronics operationally coupled to the apparatus clock and the apparatus analog reception electronics and operable to timestamp the received UWB signals with reference to the apparatus clock; and

a localization unit operationally coupled to the apparatus digital reception electronics and operable to compute a relative location of the self-localizing apparatus to the three UWB transceivers based on the timestamps of the received UWB signals.

26. A method for determining relative locations of self-localizing apparatus, comprising:

emitting a first ultra wideband (UWB) signal, using a first UWB transceiver comprising a first transceiver antenna, a first transceiver clock, first analog transmission electronics, and first digital transmission electronics, at a first scheduled transmission time with reference to the first transceiver clock;

emitting a second UWB signal, using a second UWB transceiver comprising a second transceiver antenna, a second transceiver clock, second analog transmission electronics, and second digital transmission electronics, at a second scheduled transmission time with reference to the second transceiver clock;

emitting a third UWB signal, using a third UWB transceiver comprising a third transceiver antenna, a third transceiver clock, third analog transmission electronics, and third digital transmission electronics, at a third scheduled transmission time with reference to the third transceiver clock;

receiving, using a first self-localizing apparatus, the first, second, and third UWB signals, wherein the first self-localizing apparatus comprises a first apparatus antenna, a first apparatus clock, first apparatus analog reception electronics, and first apparatus digital reception electronics operationally coupled to the first apparatus clock and the first apparatus analog reception electronics;

timestamping, using the first apparatus digital reception electronics of the first self-localizing apparatus, the received first, second, and third UWB signals with reference to the first apparatus clock;

computing, using a first localization unit operationally coupled to the first apparatus digital reception electronics, the relative location of the first self-localizing apparatus based on the timestamps of the received first, second, and third UWB signals;

receiving, using a second self-localizing apparatus, the first, second, and third UWB signals, wherein the second self-localizing apparatus comprises a second apparatus antenna, a second apparatus clock, second apparatus analog reception electronics, and second apparatus digital reception electronics operationally coupled to the second apparatus clock and the second apparatus analog reception electronics;

timestamping, using the second apparatus digital reception electronics of the second self-localizing apparatus, the received first, second, and third UWB signals with reference to the second apparatus clock; and

computing, using a second localization unit operationally coupled to the second apparatus digital reception electronics, the relative location of the second self-localizing apparatus based on the timestamps of the received first, second, and third UWB signals.