Distributed localization systems and methods and self-localizing apparatus
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.
1. A mobile robot, comprising:
an antenna;
analog reception electronics operationally coupled to the antenna;
a clock;
digital reception electronics operationally coupled to the analog reception electronics and to the clock, wherein the digital reception electronics are operable to timestamp a signal received by the antenna with reference to the clock, wherein the signal is spread over a bandwidth that exceeds the lesser of 125 MHz and 5% of an arithmetic center frequency of the signal; and
an actuator operable to affect a movement of the mobile robot based on:
at least one timestamped signal; and
a reference signal.
2. The mobile robot of claim 1 , further comprising:
an onboard sensor operable to produce an onboard sensor signal based on a global property at an onboard location,
wherein the actuator is further operable to affect the movement based on a comparison of the onboard sensor signal with an offboard sensor signal received from an offboard sensor at a remote location and produced based on the global property at the remote location.
3. The mobile robot of claim 2 , wherein the mobile robot is operable to use a global property model to compare the onboard sensor signal with the offboard sensor signal, wherein the global property model relates the onboard sensor signal and the offboard sensor signal to location, orientation, or motion of the mobile robot.
4. The mobile robot of claim 1 , further comprising:
a sensor operable to produce a sensor signal representative of an orientation of the antenna, wherein the actuator is further operable to affect the movement based on the sensor signal.
5. The mobile robot of claim 1 , wherein the reference signal is representative of a desired position or orientation of the mobile robot, and wherein the movement reduces a disturbance to the mobile robot's actual position or orientation relative to the mobile robot's desired position or orientation caused by at least one of:
a change in the antenna's orientation;
a change in the antenna's position; and
a change in the antenna's movement in less than 1 second.
6. The mobile robot of claim 1 , further comprising:
a compensation unit operable to compute a compensation for effects on the signal.
7. The mobile robot of claim 6 , further comprising:
a sensor operable to provide data representative of an orientation of the mobile robot, wherein the compensation unit is operable to compute a compensation for an effect of the orientation of the mobile robot on the signal.
8. The mobile robot of claim 6 , wherein:
the received signal comprises payload data representative of an orientation of a transceiver that transmitted the signal; and
the compensation unit is operable to compute a compensation for an effect of the orientation of the transceiver on the signal.
9. The mobile robot of claim 6 , wherein:
the mobile robot is operable to determine a relative orientation of the antenna of the mobile robot and an antenna of a transceiver that transmitted the signal; and
the compensation unit is operable to compute a compensation for an effect of the relative orientation on the signal.
10. The mobile robot of claim 6 , wherein the compensation unit is operable to compute a compensation for an effect of a reception angle of the signal.
11. The mobile robot of claim 6 , wherein:
the analog reception electronics comprise an amplifier operable to amplify the signal prior to timestamping; and
the compensation unit is operable to compute a compensation for an effect of the amplifier on the signal.
12. The mobile robot of claim 1 , wherein the mobile robot is operable to receive two signals within a time window of 10 seconds, wherein the time difference between the timestamps of the two signals is within 3 nanoseconds of the time difference between their reception times at the antenna with reference to the clock.
13. The mobile robot of claim 1 , further comprising:
at least one of a gyroscope, an accelerometer, an odometer, or an encoder,
wherein the actuator is further operable to affect the movement based on the at least one of the gyroscope, the accelerometer, the odometer, or the encoder to reduce a disturbance to the mobile robot's location in less than 1 second.
14. The mobile robot of claim 1 , wherein the actuator is further operable to affect the movement based on a signal indicative of at least one of a position, an orientation, and a movement of a transmitter producing the signal.
15. The mobile robot of claim 14 , further comprising:
a localization unit operationally coupled to the digital reception electronics and operable to compute a location of the mobile robot based on a multiple of timestamped signals; and
a control unit operable to produce a control signal based on the location,
wherein the actuator is responsive to the control signal.
16. The mobile robot of claim 1 , wherein:
the digital reception electronics of the mobile robot are operable to timestamp at least three signals received by the antenna with reference to the clock, wherein each of the at least three signals is spread over a bandwidth that exceeds the lesser of 125 MHz and 5% of an arithmetic center frequency of the signal;
the mobile robot is a first mobile robot in a system of at least two mobile robots; and
a second mobile robot of the system of at least two mobile robots is configured to timestamp the same at least three signals and affect a movement of the second mobile robot based on the at least three timestamped signals.
17. A method of operating a mobile robot, comprising:
receiving, using an antenna, a signal, wherein the signal is spread over a bandwidth that exceeds the lesser of 125 MHz and 5% of an arithmetic center frequency of the signal;
timestamping, using digital reception electronics, the received signal in reference to a clock coupled to the digital reception electronics after the signal passes through analog reception electronics operationally coupled to the antenna; and
affecting, using an actuator, movement of the mobile robot based on:
at least one timestamped signal; and
a reference signal.
18. The method of claim 17 , wherein the reference signal is representative of a desired position or orientation of the mobile robot, and wherein the movement reduces a disturbance to the mobile robot's actual position or orientation relative to the mobile robot's desired position or orientation caused by at least one of:
a change in the antenna's orientation;
a change in the antenna's position; and
a change in the antenna's movement in less than 1 second.
19. The method of claim 17 , further comprising:
computing, using a compensation unit, a compensation for effects on the signal, wherein the effects on the signal comprise one or more of: an orientation of the mobile robot, an orientation of a transceiver that transmitted the signal, a relative orientation of the antenna of the mobile robot and an antenna of a transceiver that transmitted the signal, a reception angle of the signal, and an analog reception electronics amplifier setting.
20. The method of claim 17 , further comprising:
computing, using a localization unit operationally coupled to the digital reception electronics, a location of the mobile robot based on a multiple of timestamped signals; and
producing, using a control unit, a control signal based on the location, wherein the actuator is responsive to the control signal.