Conveyor belt slippage

1. A method of controlling a printing system, the method comprising:

activating a driver to advance a conveyor belt in a plurality of sub-turns, and for each of the plurality of sub-turns:

determining a first parameter associated with movement of the conveyor belt based on data obtained from the driver;

determining a second parameter associated with movement of the conveyor belt based on data obtained from an optical sensor; and

calculating a per-sub-turn slippage parameter based on any difference between the first parameter and the second parameter,

the method further comprising:

calculating a slippage metric based on the per-sub-turn slippage parameters for the plurality of sub-turns; and

causing outputting of a conveyor belt tension adjustment indication.

2. The method of claim 1 , wherein for each of the plurality of sub-turns:

determining the first parameter comprises determining a first distance travelled by the conveyor belt during the respective sub-turn, based on data obtained from the driver; and

determining the second parameter comprises determining a second distance travelled by the conveyor belt during the respective sub-turn, based on data obtained from the optical sensor.

3. The method of claim 1 , wherein for each of the plurality of sub-turns:

determining the first parameter comprises determining a first linear velocity of the conveyor belt during the respective sub-turn, based on data obtained from the driver; and

determining the second parameter comprises determining a second linear velocity of the conveyor belt during the respective sub-turn based on data obtained from the optical sensor.

4. The method of claim 1 , wherein calculating the slippage metric comprises aggregating the per-sub-turn slippage parameters for the plurality of sub-turns.

5. The method of claim 1 , wherein calculating the slippage metric comprises:

for each of the plurality of sub-turns, comparing the per-sub-turn slippage parameter to a predetermined threshold; and

calculating a proportion of the plurality of sub-turns where the predetermined threshold is exceeded.

6. The method of claim 1 , comprising comparing the slippage metric to a predetermined threshold, and wherein outputting of the conveyor belt tension adjustment indication is caused if the predetermined threshold is exceeded.

7. A non-transitory computer-readable storage medium storing instructions that, if executed by a processor of a printing system, cause the processor to:

receive first data relating to a plurality of motions of a driver coupled to a conveyor belt;

receive second data relating to optical detection of movement of the conveyor belt;

for each of the plurality of driver motions, calculate a per-motion slippage parameter based on any discrepancy between the received first and second data;

calculate a slippage metric based on the per-motion slippage parameters; and

cause transmittal of a slippage alert signal based on a comparison of the calculated slippage metric to a predetermined threshold value.

8. The non-transitory computer-readable storage medium of claim 7 , wherein calculating the per-motion slippage parameter comprises, for each of the plurality of motions of the driver:

determining a first distance travelled by the conveyor belt based on the first data;

determining a second distance travelled by the conveyor belt based on the second data; and

calculating a difference between the first distance and the second distance.

9. The non-transitory computer-readable storage medium of claim 7 , wherein calculating the per-motion slippage parameter comprises, for each of the plurality of motions of the driver:

determining a first linear velocity of the conveyor belt based on the first data;

determining a second linear velocity of the conveyor belt based on the second data; and

calculating a difference between the first linear velocity and the second linear velocity.

10. The non-transitory computer-readable storage medium of claim 7 , wherein calculating the slippage metric comprises aggregating the per-motion slippage parameters for the plurality of motions of the driver.

11. The non-transitory computer-readable storage medium of claim 7 , wherein calculating the slippage metric comprises:

for each of the plurality of motions of the driver, comparing the per-motion slippage parameter to a predetermined threshold; and

calculating a proportion of the plurality of motions where the predetermined threshold is exceeded.

12. A printing system comprising:

a driver to advance a conveyor belt in a plurality of intervals, wherein each of the plurality of intervals comprises a sub-turn of the conveyor belt;

an optical sensor to optically detect movement of the conveyor belt; and

a diagnostic module to:

determine a first parameter associated with movement of the conveyor belt based on data from the driver;

determine a second parameter associated with movement of the conveyor belt based on data from the optical sensor;

for each of the plurality of intervals, calculate a per-interval slippage parameter based on a difference between the first parameter and the second parameter;

calculate a slippage metric based on the per-interval slippage parameters for the plurality of intervals; and

based on a comparison of the slippage metric to a predetermined threshold value, cause a conveyor belt tension adjustment indication.

13. The printing system of claim 12 , wherein the diagnostic module is to calculate the slippage metric by aggregating the per-interval slippage parameters for the plurality of motions of the driver.

14. The printing system of claim 12 , wherein the diagnostic module is to calculate the slippage metric by, for each of the plurality of intervals of the driver, comparing the per-interval slippage parameter to a predetermined threshold and calculating a proportion of the plurality of intervals where the predetermined threshold is exceeded.

15. The printing system of claim 12 , wherein the first parameter and the second parameter are each a distance travelled by the conveyor belt in the respective interval of the driver.