Systems and methods for synchronizing sensor capture
In one embodiment, a method includes, by a computing device of a first sensor receiving synchronization information from a controller. The synchronization information being generated based on a clock of the controller. The method also includes determining, based on the synchronization information, a first offset between a first clock of the first sensor and the clock of the controller; storing the first offset; and synchronizing, based on the stored first offset and the first clock of the first sensor, a first data capture by the first sensor with a second data capture by a second sensor. The first data capture and the second data capture being requested by the controller.
1. A method comprising, by
one or more processors of a first sensor associated with a vehicle:
receiving synchronization information from a timing controller, the synchronization information being generated based on a clock of the timing controller;
determining, based on the synchronization information, a first offset between a first clock of the first sensor and the clock of the timing controller;
calculating, based on the first offset, one or more entries for inclusion in a synchronization table, wherein the synchronization table is configured to convert timing information generated relative to the clock of the timing controller to first timing information associated with the first clock of the first sensor; and
updating the synchronization table based on the one or more entries.
2. The method of claim 1 , wherein receiving synchronization information from the timing controller comprises receiving a periodic pulse train on one or more channels utilized to transmit synchronization information from the timing controller to the first sensor.
3. The method of claim 2 , wherein the periodic pulse train comprises a periodic series including a predetermined N number of pulses.
4. The method of claim 3 , further comprising calculating the one or more entries for inclusion in the synchronization table by determining a duration and an interval between each of the predetermined N number of pulses.
5. The method of claim 1 , further comprising calculating the one or more entries based on:
(1) a quotient of a local timing value and a predetermined fixed incrementation of a counter of the clock of the timing controller; and
(2) a quotient of an expected pulse length and a timed pulse length received at the first sensor.
6. The method of claim 1 , wherein the first offset comprises a frequency offset and a phase offset between the first clock of the first sensor and the clock of the timing controller.
7. The method of claim 1 , wherein receiving synchronization information from the timing controller comprises receiving a coded-pulse train on one or more channels utilized to asynchronously transmit synchronization information from the timing controller to the first sensor.
8. The method of claim 1 , further comprising performing, based on the first offset and the first timing information, a first data capture by the first sensor synchronized with a second data capture by a second sensor.
9. The method of claim 1 , wherein the first sensor is disposed on the vehicle.
10. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of a first sensor associated with a vehicle, cause the one or more processors to:
receive synchronization information from a timing controller, the synchronization information being generated based on a clock of the timing controller;
determine, based on the synchronization information, a first offset between a first clock of the first sensor and the clock of the timing controller;
calculate, based on the first offset, one or more entries for inclusion in a synchronization table, wherein the synchronization table is configured to convert timing information generated relative to the clock of the timing controller to first timing information associated with the first clock of the first sensor; and
update the synchronization table based on the one or more entries.
11. The non-transitory computer-readable medium of claim 10 , wherein the instructions to receive synchronization information from the timing controller further comprises instructions to receive a periodic pulse train on one or more channels utilized to transmit synchronization information from the timing controller to the first sensor.
12. The non-transitory computer-readable medium of claim 11 , wherein the periodic pulse train comprises a periodic series including a predetermined N number of pulses.
13. The non-transitory computer-readable medium of claim 12 , further comprising instructions to calculate the one or more entries for inclusion in the synchronization table by determining a duration and an interval between each of the predetermined N number of pulses.
14. The non-transitory computer-readable medium of claim 10 , wherein the instructions to calculate the one or more entries further comprises instructions to calculate the one or more entries based on:
(1) a quotient of a local timing value and a predetermined fixed incrementation of a counter of the clock of the timing controller; and
(2) a quotient of an expected pulse length and a timed pulse length received at the first sensor.
15. The non-transitory computer-readable medium of claim 10 , wherein the first offset comprises a frequency offset and a phase offset between the first clock of the first sensor and the clock of the timing controller.
16. The non-transitory computer-readable medium of claim 10 , wherein the instructions to receive synchronization information from the timing controller further comprises instructions to receive a coded-pulse train on one or more channels utilized to asynchronously transmit synchronization information from the timing controller to the first sensor.
17. A system associated with a vehicle, comprising:
a first sensor;
a timing controller;
one or more non-transitory computer-readable storage media including instructions; and
one or more processors coupled to the one or more non-transitory computer-readable storage media, the one or more processors configured to execute the instructions to:
receive synchronization information from a timing controller, the synchronization information being generated based on a clock of the timing controller;
determine, based on the synchronization information, a first offset between a first clock of the first sensor and the clock of the timing controller;
calculate, based on the first offset, one or more entries for inclusion in a synchronization table, wherein the synchronization table is configured to convert timing information generated relative to the clock of the timing controller to first timing information associated with the first clock of the first sensor; and
update the synchronization table based on the one or more entries.
18. The system of claim 17 , wherein the instructions to receive synchronization information from the timing controller further comprises instructions to receive a periodic pulse train on one or more channels utilized to transmit synchronization information from the timing controller to the first sensor.
19. The system of claim 18 , wherein the periodic pulse train comprises a periodic series including a predetermined N number of pulses.
20. The system of claim 19 , further comprising instructions to calculate the one or more entries for inclusion in the synchronization table by determining a duration and an interval between each of the predetermined N number of pulses.