System and method for determining a position of a movable object, arrangement of general lighting LED and light sensor for a position determination of a movable object

• US 8,805,645 B2
• Filed: 07/19/2011
• Issued: 08/12/2014
• Est. Priority Date: 07/21/2010
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Giesekus, Joachim
• Primary Examiner(s): Barbee, Manuel L
• Application Number:
  US13/186,305
• Publication Number:
  US 20120022826A1
• Time in Patent Office: 1,120 Days
• Field of Search: 702/94, 702/95, 702150-152, 356/3.05, 356/3.1, 356/3.12, 356/4.01, 356/614, 356/615, 356/623
• US Class Current: 702/152
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves

Abstract

A system for determining a position of a moving object is described, having: an arrangement having at least three general lighting LEDs, wherein each of the general lighting LEDs is implemented to transmit one light signal each with a transmission time information and a transmitter information, wherein the wavelength ranges of the general lighting LEDs for the signal transmission overlap, wherein the transmitter information enables at least a determination of a position of the respective general lighting LEDs and the transmission time information is information on a point in time when the respective signal was transmitted; a light sensor mounted to the moving object and implemented to receive the light signals and allocate one signal receive time each; and an evaluation unit which is implemented to determine the position of the object based on the transmitter information, the transmission time information and the receive time information.

Claims

1. A system for determining a position of a moving object, comprising:

an arrangement comprising at least three general lighting LEDs, wherein a first general lighting LED of the at least three general lighting LEDs is implemented to transmit a first light signal comprising a first transmission time information and a first transmitter information in a first wavelength range, wherein the first transmitter information enables at least a determination of a position of the first general lighting LED and the first transmission time information is information on a point in time when the first signal was transmitted, wherein a second general lighting LED of the at least three general lighting LEDs is implemented to transmit a second light signal comprising a second transmission time information and a second transmitter information in a second wavelength range, wherein the second transmitter information enables at least a determination of a position of the second general lighting LED, and the second transmission time information is information on a point in time when the second signal was transmitted, wherein a third general lighting LED of the at least three general lighting LEDs is implemented to transmit a third light signal comprising a third transmission time information and a third transmitter information in a third wavelength range, wherein the third transmitter information enables at least a determination of a position of the third general lighting LED and the third transmission time information is information on a point in time when the third signal was transmitted, and wherein the first wavelength range, the second wavelength range and the third wavelength range at least partially overlap in an overlapping range;

a light sensor mounted to the moving object and implemented to receive the first to third light signals in the overlapping range and allocate a first signal receive time to the first light signal, allocate a second signal receive time to the second light signal and a third signal receive time to the third light signal, and

an evaluation unit which is implemented to determine the position of the object based on the first to third transmitter information, the first to third transmission time information and the first to third receive time information,

wherein the first general lighting LED is a first fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion indirectly generated via a fluorescence layer, and to transmit the first light signal simultaneously by modulating an excitation current of the first fluorescence LED, wherein a wavelength range of the light portion directly generated by the first fluorescence LED forms the first wavelength range,

wherein the second general lighting LED is a second fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion generated indirectly via a fluorescence layer, and to transmit the second signal simultaneously by modulating an excitation current of the second fluorescence LED, wherein a wavelength range of the light portion generated directly by the second fluorescence LED forms the second wavelength range, and

wherein the third general lighting LED is a third fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion generated indirectly via a fluorescence layer, and to transmit the third signal simultaneously by modulating an excitation current of the third fluorescence LED, wherein a wavelength range of the light portion generated directly by the third fluorescence LED forms the third wavelength range.

2. The system according to claim 1, wherein the light sensor is implemented to only evaluate light portions within the overlapping range to determine the first to third signal receive times.

3. The system according to claim 2, wherein the light sensor comprises a filter which is more transmissive in the overlapping range than in wavelength ranges generated by the first, second or third general lighting LED.

4. The system according to claim 2, wherein the overlapping range is in a wavelength range from 420 nm to 490 nm.

5. The system according to claim 1, comprising:

a transmitter mounted to the moving object; and

a receiver, wherein the transmitter is implemented to transmit a signal to the receiver for a data transmission via a contactless interface.

6. The system according to claim 5, wherein the transmitter is a further general lighting LED and the receiver is a further light sensor.

7. The system according to claim 1, wherein the arrangement of the at least three general lighting LEDs and the light sensor are implemented to transmit the first to third light signal in a time division multiplexing method, wherein the first general lighting LED is implemented to transmit the first light signal in a first time slot of the time division multiplexing method, the second general lighting LED is implemented to transmit the second light signal in a second time slot of the time division multiplexing method and the third general lighting LED is implemented to transmit the third light signal in a third time slot of the time division multiplexing method.

8. The system according to claim 1, wherein the evaluation unit is mounted to the moving object or arranged at another location.

9. The system according to claim 1, wherein the evaluation unit is implemented to determine the position by means of a TDOA method (Time Difference of Arrival).

10. The system according to claim 1, wherein the light sensor is synchronized with the at least three general lighting LEDs and comprises a common time reference and wherein the evaluation unit is implemented to determine the position of the object by means of a TOA method (Time of Arrival).

11. A light sensor for a position determination of a moving object, when the light sensor is mounted to the moving object, wherein the light sensor is implemented to receive a first light signal of a first general lighting LED comprising a first transmitter identification and a first transmission time information in a first wavelength range, and to allocate a first receive time information to the first light signal, to receive a second light signal of a second general lighting LED comprising a second transmitter identification and a second transmission time information in a second wavelength range and to allocate a second receive time information to the second light signal, and to receive a third light signal from a third general lighting LED comprising a third transmitter identification and a third transmission time information in a third wavelength range and to allocate the third receive time information to the third light signal and to provide the first to third receive time information for position determination, wherein the first wavelength range, the second wavelength range and the third wavelength range at least partially overlap in an overlapping range, wherein the light sensor is implemented to evaluate only light portions in the overlapping range to determine the first to third signal receive time.

12. A system for determining a position of a moving object, comprising:

an arrangement of at least three general lighting LEDs, wherein a first general lighting LED of the at least three general lighting LEDs is implemented to transmit a first pulse-type light signal in a first wavelength range at a first transmission time, wherein a second general lighting LED of the at least three general lighting LEDs is implemented to transmit a second pulse-type light signal in a second wavelength range at a second transmission time comprising a first transmission time difference at the first transmission time, wherein a third general lighting LED of the at least three general lighting LEDs is implemented to transit a third pulse-type light signal in a third wavelength range at a third transmission time comprising a second transmission time difference at the first transmission time, wherein the first to third pulse-type light signals comprise an identical pulse-type form, and wherein the first wavelength range, the second wavelength range and the third wavelength range at least partially overlap in an overlapping range;

a light sensor mounted to the moving object and implemented to receive the first to third light signal in the overlapping range and generate a receive signal by means of overlaying the first to third light signal; and

an evaluation unit which is implemented to control the second general lighting LED and/or the third general lighting LED based on an evaluation of the form of the receive signal such that the second transmission time and/or the third transmission time are shifted with respect to the first transmission time such that the first to third light signal are simultaneously received by the light sensor and the evaluation unit is further implemented, based on a position of the first general lighting LED, a position of the second general lighting LED, a position of the third general lighting LED and the first and/or the second transmission time difference, to determine the position of the moving object.

13. The system according to claim 12, wherein the first general lighting LED is a first fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion with a light portion indirectly generated via a fluorescence layer and to transmit the first light signal simultaneously by modulating an excitation current of the first fluorescence LED, wherein a wavelength range of the light portion directly generated by the first fluorescence LED forms the first wavelength range,

wherein the second general lighting LED is a second fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion indirectly generated via a fluorescence layer, and to transmit the second signal simultaneously by modulating an excitation current of the second fluorescence LED, wherein a wavelength range of the light portion directly generated by the second fluorescence LED forms the second wavelength range, and

wherein the third general lighting LED is a third fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion indirectly generated via a fluorescence layer, and to transmit the third signal simultaneously by modulating an excitation current of the third fluorescence LED, wherein a wavelength range of the light portion directly generated by the third fluorescence LED forms the third wavelength range.

14. The system according to claim 12, wherein the light sensor is implemented to evaluate only light portions in the overlapping range to determine the first to third signal receive time.

15. The system according to claim 14, wherein the light sensor comprises a filter which is more transmissive in the overlapping range than in other wavelength ranges generated by the first, second and third general lighting LEDs.

16. The system according to claim 14, wherein the overlapping range is in a wavelength range from 420 nm to 490 nm.

17. A method for determining a position of a moving object, comprising:

transmitting a first light signal comprising a first transmission time information and a first transmitter information in a first wavelength range, by a first general lighting LED, wherein the first transmitter information enables at least a determination of a position of the first general lighting LED and the first transmission time information is information about a point in time when the first signal was transmitted;

transmitting a second light signal comprising a second transmission time information and a second transmitter information in a second wavelength range by a second general lighting LED, wherein the second transmitter information enables at least a determination of a position of the second general lighting LED and the second transmission time information is information about a point in time when the second signal was transmitted;

transmitting a third light signal comprising a third transmission time information and a third transmitter information in a third wavelength range by a third general lighting LED, wherein the third transmitter information enables at least a determination of a position of the third general lighting LED and the third transmission time information is information about a point in time when the third signal was transmitted, wherein the first wavelength range, the second wavelength range and the third wavelength range at least partially overlap in an overlapping range;

receiving the first to third light signals in the overlapping range by a light sensor mounted to the moving object;

allocating a first signal receive time to the first light signal;

allocating a second signal receive time to the second light signal;

allocating a third signal receive time to the third light signal; and

determining the position of the object based on the first to third transmitter information, the first to third transmission time information and the first to third receive time information,

wherein the first general lighting LED is a first fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion indirectly generated via a fluorescence layer, and to transmit the first light signal simultaneously by modulating an excitation current of the first fluorescence LED, wherein a wavelength range of the light portion directly generated by the first fluorescence LED forms the first wavelength range,

wherein the second general lighting LED is a second fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion generated indirectly via a fluorescence layer, and to transmit the second signal simultaneously by modulating an excitation current of the second fluorescence LED, wherein a wavelength range of the light portion generated directly by the second fluorescence LED forms the second wavelength range, and

wherein the third general lighting LED is a third fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion generated indirectly via a fluorescence layer, and to transmit the third signal simultaneously by modulating an excitation current of the third fluorescence LED, wherein a wavelength range of the light portion generated directly by the third fluorescence LED forms the third wavelength range.

18. A method for determining a position of a moving object, comprising:

transmitting a first pulse-type light signal in a first wavelength range by a first general lighting LED at a first transmission time;

transmitting a second pulse-type light signal in a second wavelength range by a second general lighting LED at a second transmission time comprising a first transmission time difference to the first transmission time;

transmitting a third pulse-type light signal in a third wavelength range by a third general lighting LED at a third transmission time comprising a second transmission time difference to the first transmission time, wherein the first to third pulse-type light signal comprise an identical pulse-like form and wherein the first wavelength range, the second wavelength range and the third wavelength range at least partially overlap in an overlapping range;

receiving the first to third light signals in the overlapping range by a light sensor mounted to the moving object;

generating a receive signal by means of overlaying the first to third light signals; and

controlling the second general lighting LED and/or the third general lighting LED based on an evaluation of a form of the receive signal such that the second transmission time and/or the third transmission time are shifted with respect to the first transmission time such that the first to third light signals are received simultaneously by the light sensor;

determining the position of the moving object based on a position of the first general lighting LED, a position of the second general lighting LED, a position of the third general lighting LED and the first and/or the second transmission time difference.

19. A non-transitory computer readable medium comprising a program code for executing a method for determining a position of a moving object;

comprising;

transmitting a first light signal comprising a first transmission time information and a first transmitter information in a first wavelength range, by a first general lighting LED, wherein the first transmitter information enables at least a determination of a position of the first general lighting LED and the first transmission time information is information about a point in time when the first signal was transmitted;

transmitting a second light signal comprising a second transmission time information and a second transmitter information in a second wavelength range by a second general lighting LED, wherein the second transmitter information enables at least a determination of a position of the second general lighting LED and the second transmission time information is information about a point in time when the second signal was transmitted;

transmitting a third light signal comprising a third transmission time information and a third transmitter information in a third wavelength range by a third general lighting LED, wherein the third transmitter information enables at least a determination of a position of the third general lighting LED and the third transmission time information is information about a point in time when the third signal was transmitted, wherein the first wavelength range, the second wavelength range and the third wavelength range at least partially overlap in an overlapping range;

receiving the first to third light signals in the overlapping range by a light sensor mounted to the moving object;

allocating a first signal receive time to the first light signal;

allocating a second signal receive time to the second light signal;

allocating a third signal receive time to the third light signal; and

determining the position of the object based on the first to third transmitter information, the first to third transmission time information and the first to third receive time information,

wherein the first general lighting LED is a first fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion indirectly generated via a fluorescence layer, and to transmit the first light signal simultaneously by modulating an excitation current of the first fluorescence LED, wherein a wavelength range of the light portion directly generated by the first fluorescence LED forms the first wavelength range,

wherein the second general lighting LED is a second fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion generated indirectly via a fluorescence layer, and to transmit the second signal simultaneously by modulating an excitation current of the second fluorescence LED, wherein a wavelength range of the light portion generated directly by the second fluorescence LED forms the second wavelength range, and

wherein the third general lighting LED is a third fluorescence LED which is implemented to generate white light for a general lighting by mixing a directly generated light portion and a light portion generated indirectly via a fluorescence layer, and to transmit the third signal simultaneously by modulating an excitation current of the third fluorescence LED, wherein a wavelength range of the light portion generated directly by the third fluorescence LED forms the third wavelength range,

when the computer program is executed on a computer.

20. A non-transitory computer readable medium comprising a program code for executing a method for determining a position of a moving object, comprising:

transmitting a first pulse-type light signal in a first wavelength range by a first general lighting LED at a first transmission time;

transmitting a second pulse-type light signal in a second wavelength range by a second general lighting LED at a second transmission time comprising a first transmission time difference to the first transmission time;

transmitting a third pulse-type light signal in a third wavelength range by a third general lighting LED at a third transmission time comprising a second transmission time difference to the first transmission time, wherein the first to third pulse-type light signal comprise an identical pulse-like form and wherein the first wavelength range, the second wavelength range and the third wavelength range at least partially overlap in an overlapping range;

receiving the first to third light signals in the overlapping range by a light sensor mounted to the moving object;

generating a receive signal by means of overlaying the first to third light signals; and

controlling the second general lighting LED and/or the third general lighting LED based on an evaluation of a form of the receive signal such that the second transmission time and/or the third transmission time are shifted with respect to the first transmission time such that the first to third light signals are received simultaneously by the light sensor;

determining the position of the moving object based on a position of the first general lighting LED, a position of the second general lighting LED, a position of the third general lighting LED and the first and/or the second transmission time difference,

when the computer program is executed on a computer.