Transmitter and receiver localization
Methods and apparatus for transmitter and receiver localization within an environment. A transmitter transmits a signal that includes information (e.g., wavelength, polarization, and/or modulation) that varies based on observation angle. Receiver(s) may estimate direction of the transmitter in the environment based on the received signal. Intensity of the signal may be used to determine distance of the transmitter to the receiver(s). The receiver(s) may then convey the respective estimated distance and direction to the transmitter, for example via a wireless connection. The transmitter may then generate a map of the respective distances and directions to receiver(s) in the environment, and may convey absolute location and orientation of the transmitter in the environment to the receiver(s), for example via a wireless connection.
1. A device, comprising:
a receiver configured to:
receive a signal from a transmitter in an environment, wherein the signal encodes digital information specific to the transmitter and includes a plurality of signal components, including:
(a) a plurality of directional signal components transmitted with different wave characteristics for different transmission directions, and
(b) a uniform signal component transmitted with a uniform wave characteristic in all transmission directions, the uniform wave characteristic being different from the different wave characteristics of the directional signal components; and
one or more processors configured to:
estimate a distance and a direction of the transmitter with respect to the receiver in the environment, wherein:
(a) the received signal is filtered to detect one or more of the directional signal components transmitted with the different wave characteristics in the received signal, that are dependent on the direction of the transmitter, and
(b) the detected one or more directional signal components are normalized based on the uniform signal component to estimate the direction; and
cause the estimated distance and direction of the transmitter with respect to the receiver to be conveyed to the transmitter.
2. The device as recited in claim 1 , wherein the device is further configured to receive information indicating absolute location and orientation of the transmitter in the environment from the transmitter.
3. The device as recited in claim 1 , wherein the distance and the direction of the transmitter are estimated in world coordinates of the transmitter.
4. The device as recited in claim 1 , wherein the device and the transmitter both include wireless technology, and wherein the one or more processors convey the estimated distance and direction to the transmitter via a wireless connection.
5. The device as recited in claim 1 , wherein the signal is a light signal, and wherein the one or more processors estimate the direction of the transmitter based on a wavelength of the one or more directional signal components detected at the receiver.
6. The device as recited in claim 1 , wherein the signal is an infrared, near-infrared, or visible light signal, and wherein the one or more processors estimate the direction of the transmitter based on a polarization of the one or more directional signal components detected at the receiver.
7. The device as recited in claim 1 , wherein the signal is an infrared, near-infrared, or visible light signal, and wherein the one or more processors estimate the direction of the transmitter based on modulation of the one or more directional signal components received at the receiver.
8. The device as recited in claim 1 , wherein the signal is an infrared, near-infrared, or visible light signal, and wherein the one or more processors estimate the distance of the transmitter based on intensity of the signal received at the receiver.
9. The device as recited in claim 1 , wherein the receiver includes a camera, and wherein the one or more processors estimate the distance to the transmitter based on a comparison of an image of the transmitter captured by the camera and a known size of the transmitter.
10. A device, comprising:
one or more processors; and
a transmitter configured to broadcast a light signal in an environment, wherein the light signal encodes digital information specific to the transmitter under control of the one or more processors, wherein the light signal conveys information and is transmitted with a plurality of signal components, including:
(a) a plurality of directional signal components transmitted with different wave characteristics for different transmission directions, and
(b) a uniform signal component transmitted with a uniform wave characteristic in all transmission directions, the uniform wave characteristic being different from the different wave characteristics of the directional signal components,
wherein the light signal is filtered to detect the one or more directional signal components with the different wave characteristics, and the one or more directional signal components are used normalized based on the uniform signal component at one or more receivers in the environment to determine respective distance and direction of the transmitter from the one or more receivers in world coordinates of the transmitter; and
wherein the device is configured to receive indications of respective determined distance and direction of the transmitter from the one or more receivers in the environment.
11. The device as recited in claim 10 , wherein the device and the one or more receivers include wireless technology, and wherein the device receives the indications of respective distance and direction from the one or more receivers via a wireless connection.
12. The device as recited in claim 10 , wherein the one or more processors are configured to generate a map of relative distances and directions of the one or more receivers with respect to the transmitter based on the received indications of respective distance and direction.
13. The device as recited in claim 10 , wherein the device stores an absolute location and orientation of the device in the environment, and wherein the device is further configured to convey the absolute location and orientation of the device to the one or more receivers.
14. The device as recited in claim 10 , wherein, to convey the information, the transmitter emits light at wavelengths that vary with a 1:1 correspondence to observation angle.
15. The device as recited in claim 10 , wherein, to convey the information, the transmitter emits light at polarizations that vary with a 1:1 correspondence to observation angle.
16. The device as recited in claim 10 , wherein, to convey the information, the transmitter emits light with modulation that varies with a 1:1 correspondence to observation angle.
17. The device as recited in claim 16 , wherein the modulation conveys data that indicates respective observation angles.
18. The device as recited in claim 10 , wherein, to convey the information, the transmitter emits light at frequencies that vary with a 1:1 correspondence to observation angle.
19. The device as recited in claim 10 , wherein the digital information encoded in the light signal varies according to the direction of the one or more receivers with respect to the transmitter.
20. A method, comprising:
receiving, at a receiver of a receiving device, a light signal from a transmitter in an environment, wherein the light signal encodes digital information specific to the transmitter and includes a plurality of signal components, including:
(a) a plurality of directional signal components transmitted with different wave characteristics for different transmission directions, and
(b) a uniform signal component transmitted with a uniform wave characteristic in all transmission directions, the uniform wave characteristic being different from the different wave characteristics of the directional signal components;
estimating, by one or more processors of the receiving device, a distance and a direction of the transmitter with respect to the receiver in the environment, wherein:
(a) the received light signal is filtered to detect one or more of the directional signal components with the different wave characteristics in the received signal, and
(b) the detected one or more directional signal components are normalized based on the uniform signal component to estimate the direction; and
conveying the estimated distance and direction of the transmitter with respect to the receiver to the transmitter.