Detecting a location of an autonomous device

1. An autonomous device configured to move within a space, the autonomous device comprising:

a first system to detect a first location of the autonomous device within the space, the first location being based on a first fixed reference;

a second system to detect a second location of the autonomous device within the space, the second location being based on a second fixed reference;

a third system to detect a third location of the autonomous device within the space based on relative movements of the autonomous device; and

one or more processing devices to select one of the first location or the second location that is closer to the third location, and to control movement of the autonomous device using an estimated location that is based on the third location and the selected one of the first location or the second location and that is determined through one or more calculations that involve the third location and the selected one of the first location or the second location;

wherein the second system comprises:

a transmitter for transmitting signals; and

a receiver for receiving timestamp messages based on the signals;

wherein the one or more processing devices are configured to determine the second location based on a transmitted signal and a timestamp message corresponding to the transmitted signal, the timestamp message containing a time that the transmitted signal was received by a remote receiver, the second fixed reference comprising the remote receiver.

2. The autonomous device of claim 1 , wherein the one or more processing devices are configured to determine a reliability of at least one of the first location or the second location by setting mathematical limits of a particle filter, and to determine if visualization data upon which the first location is based exceeds the mathematical limits of the particle filter.

3. The autonomous device of claim 1 , wherein the first system comprises a vision system configured to detect landmarks within the space that are within a predefined distance of the autonomous device, the landmarks comprising the first fixed reference.

4. The autonomous device of claim 1 , wherein the first system comprises a laser-based vision system.

5. The autonomous device of claim 1 , wherein the one or more processing devices are configured to obtain the estimated location by averaging the second location and the third location.

6. The autonomous device of claim 1 , wherein the one or more processing devices are configured to obtain the estimated location by obtaining a weighted average of the second location and the third location.

7. The autonomous device of claim 1 , wherein the one or more processing devices are configured to obtain the estimated location based also on one or more prior estimated locations of the autonomous device.

8. The autonomous device of claim 1 , wherein the estimated location of the autonomous device is obtained by processing the second location and the third location using a finite impulse response filter.

9. The autonomous device of claim 1 , wherein the estimated location of the autonomous device is obtained by processing the second location and the third location using a Kalman filter or a particle filter.

10. The autonomous device of claim 1 , wherein the one or more processing devices are configured to determine the estimated location of the autonomous device based on both of the second location and the third location.

11. The autonomous device of claim 1 , wherein the one or more processing devices are configured to determine a reliability of at least one of the first location or the second location by comparing the first location and the second location to the third location.

12. The autonomous device of claim 11 , wherein the first system comprises a light detection and ranging (LIDAR) system.

13. The autonomous device of claim 1 , further comprising:

a body; and

wheels to move the body;

wherein the third system comprises an odometry system, the odometry system being configured to determine the third location based on movements of the wheels, the relative movements of the autonomous device being based on the movements of the wheels.

14. The autonomous device of claim 13 , wherein the odometry system comprises encoders connected to the wheels, the encoders providing information about rotation of the wheels.

15. The autonomous device of claim 13 , wherein the information about rotation of the wheels comprises degrees of rotation of the wheels.

16. The autonomous device of claim 1 , wherein the one or more processing devices are configured to perform operations comprising:

determining a level of reliability of the first location; and

comparing the determined level of reliability to a predefined level of reliability to identify that the first location has less than the predefined level of reliability;

wherein determining the level of reliability of the first location comprises using a filter to compare visual data based on the first fixed reference to known features in a database.

17. The autonomous device of claim 16 , wherein the one or more processing devices are configured to determine the level of reliability of the first location using a particle filter.

18. An autonomous device configured to move within a space, the autonomous device comprising:

a first system to detect a first location of the autonomous device within the space, the first location being based on a first fixed reference;

a second system to detect a second location of the autonomous device within the space, the second location being based on a second fixed reference;

a third system to detect a third location of the autonomous device within the space based on relative movements of the autonomous device; and

one or more processing devices to select one of the first location or the second location that is closer to the third location, and to control movement of the autonomous device using an estimated location that is based on the third location and the selected one of the first location or the second location and that is determined through one or more calculations that involve the third location and the selected one of the first location or the second location;

wherein the second system comprises:

a transmitter for transmitting signals; and

a receiver for receiving timestamp messages and signals;

wherein the one or more processing devices are configured to determine the second location based on a transmitted signal and a timestamp message corresponding to the transmitted signal, the timestamp message containing a time that the transmitted signal was received by a remote receiver, the second fixed reference comprising the remote receiver; and

wherein the one or more processing devices are configured to determine the second location based also on a received signal and a timestamp message corresponding to the received signal, the timestamp message containing a time that the received signal was transmitted by the remote receiver.

19. The autonomous device of claim 18 , wherein the first system comprises a vision system configured to detect landmarks within the space that are within a predefined distance of the autonomous device, the landmarks comprising the first fixed reference.

20. The autonomous device of claim 18 , further comprising:

a body; and

wheels to move the body;

wherein the third system comprises an odometry system, the odometry system being configured to determine the third location based on movements of the wheels, the relative movements of the autonomous device being based on the movements of the wheels.

21. The autonomous device of claim 18 , wherein the estimated location of the autonomous device is obtained by processing the second location and the third location using a finite impulse response filter.

22. An autonomous device configured to move within a space, the autonomous device comprising:

a first system to detect a first location of the autonomous device within the space, the first location being based on a first fixed reference;

a second system to detect a second location of the autonomous device within the space, the second location being based on a second fixed reference;

a third system to detect a third location of the autonomous device within the space based on relative movements of the autonomous device; and

one or more processing devices to determine an estimated location of the autonomous device within the space through one or more calculations that involve the second location and the third location, the estimated location being based on the second location and the third location, and to control movement of the autonomous device using the estimated location in a case that the estimated location is closer to the third location than the first location is to the third location;

wherein the second system comprises:

a transmitter for transmitting signals; and

a receiver for receiving timestamp messages based on the signals;

wherein the one or more processing devices are configured to determine the second location based on a transmitted signal and a timestamp message corresponding to the transmitted signal, the timestamp message containing a time that the transmitted signal was received by a remote receiver, the second fixed reference comprising the remote receiver.

23. The autonomous device of claim 22 , wherein the one or more processing devices are configured to determine the estimated location of the autonomous device based on both of the second location and the third location.

24. An autonomous device configured to move within a space, the autonomous device comprising:

a first system comprising a vision system that uses machine vision to detect a first location of the autonomous device within the space, the first location being based on a first fixed reference;

a second system comprising a triangulation system that uses triangulation to detect a second location of the autonomous device within the space, the second location being based on a second fixed reference, the triangulation system having an offset from the vision system; and

one or more processing devices to perform calibration of the second system to the first system by adding the offset to, or subtracting the offset from, the second location to produce a calibrated second location, to determine a reliability of the first location, and to control movement of the autonomous device using the calibrated second location in a case that the first location has less than a predefined level of reliability.

25. The autonomous device of claim 24 , further comprising:

a third system to detect a third location of the autonomous device within the space based on relative movements of the autonomous device.