Data logging system and method
A data logging system for logging input data received from a data source is described. The data logging system has a data storage memory. A data input is arranged to repeatedly receive input data having a temporal input data resolution. A write controller is arranged to write newly received input data as received via the data input into the data storage memory. The writing comprises writing the newly received input data at the temporal input data resolution. The writing comprises keeping recent data at the temporal input data resolution in the data storage memory, and overwriting part of old data with newly received input data while keeping another part of the old data in the data storage memory at lower data resolution.
1. A data logging system for logging input data received from a data source, the data logging system comprising:
a data storage memory arranged to store a plurality of data at a plurality of data storage locations; and
a data storage controller comprising:
a data input arranged to repeatedly receive input data having a temporal input data resolution from the data source, and
a write controller arranged to write newly received input data as received via the data input into the data storage memory, the write controller being arranged to, in writing the newly received input data as received via the data input into the data storage memory:
write the newly received input data at the temporal input data resolution,
if the data storage memory comprises recent data: keep the recent data at the temporal input data resolution in the data storage memory, and
if the data storage memory comprises old data: overwrite part of the old data with at least part of the newly received input data while keeping another part of the old data in the data storage memory at a first temporal aged data resolution,
the recent data corresponding to input data previously written into the data storage memory and satisfying a pre-determined recent age criterion,
the old data corresponding to input data previously written into the data storage memory and satisfying a first pre-determined age criterion,
the first temporal aged data resolution being lower than the temporal input data resolution, and
the first pre-determined age criterion being associated with input data having a higher age than input data satisfying the pre-determined recent age criterion.
2. A data logging system according to claim 1 , the write controller comprising:
a location allocator arranged to:
determine which data storage locations comprise the old data, and
determine which of the data storage locations comprising the old data are available to be overwritten with newly received input data.
3. A data logging system according to claim 1 , the write controller being arranged to write into the data storage memory using a file system for writing the newly received input data to the data storage memory.
4. A data logging system according to claim 1 , the first temporal aged data resolution being at least a factor of 2 lower than the temporal input data resolution.
5. A data logging system according to claim 1 , the write controller being arranged to use at most half of the data storage locations of the plurality of data storage locations for storage of the recent data at the temporal input data resolution.
6. A data logging system according to claim 1 , the write controller being further arranged to, in writing the newly received input data as received via the data input into the data storage memory:
if the data storage memory comprises older data:
overwrite part of the older data with newly received input data while keeping another part of the older data in the data storage memory at a second temporal aged data resolution,
the older data corresponding to input data previously written into the data storage memory and satisfying a second pre-determined age criterion,
the second temporal aged data resolution being lower than the first temporal aged data resolution, and
the second pre-determined age criterion being associated with input data having a higher age than input data satisfying the first pre-determined age criterion.
7. A data logging system according to claim 1 , the write controller being further arranged to, in writing newly received input data as received via the data input into the data storage memory:
if the data storage memory comprises oldest data:
overwrite the oldest data with newly received input data,
the oldest data corresponding to input data previously written into the data storage memory and satisfying a third pre-determined age criterion, and
the third pre-determined age criterion being associated with input data having a higher age than input data satisfying the first pre-determined age criterion, and, as far as dependent on claim 6 , the second pre-determined age criterion.
8. A data logging system according to claim 1 , the data logging system comprising or being arranged to cooperate with:
an event analyser arranged to:
analyse the input data to check whether the input data corresponds to an occurrence of one or more events from a group consisting of one or more pre-determined events; and
provide an event signal to the data logging system in case the input data corresponds to such occurrence; and
the data logging system being arranged to react on the event signal.
9. A data logging system according to claim 8 , the data logging system being arranged to, in reacting on the event signal, prevent at least input data present in the data storage memory at the temporal input data resolution satisfying a further pre-determined age criterion, from being overwritten until a release condition is satisfied, the further pre-determined age criterion being associated at least with a lower age than that associated with the first pre-determined age criterion.
10. A data logging system according to claim 1 the storage controller further comprising:
a read controller arranged to retrieve the recent data from the data storage memory at the temporal input data resolution, and
a data output arranged to obtain the recent data as retrieved by the read controller from the read controller and to provide the recent data to an output terminal connectable to a data consumer.
11. A data logging system according to claim 10 ,
the read controller further arranged to retrieve the old data from the data storage memory at the first temporal aged data resolution, and
the data output further arranged to obtain the old data as retrieved by the read controller from the read controller and to provide the old data at the first temporal aged data resolution to the output terminal.
12. A data logging system according to claim 10 ,
the read controller further arranged to retrieve the old data from the data storage memory at the first temporal aged data resolution,
the read controller further comprising an up-convertor arranged to up-convert the old data as retrieved from the first temporal aged data resolution to the temporal input data resolution to obtain a reconstructed input data at a temporal resolution corresponding to the temporal input data resolution, and
the data output further arranged to provide the reconstructed input data at the temporal resolution to the output terminal.
13. An image logging system, the image logging system comprising a data logging system according to claim 1 and a camera, the input data comprising at least images captured by the camera.
14. A black box system, the black box system comprising a data logging system according to claim 1 and one or more data sources of a group consisting of a on-board camera, a voice recorder, a vehicle's performance monitor, an environmental information monitor and a geographic position detector, the input data comprising data from the one or more data sources.
15. A camera surveillance system comprising an image logging system according to claim 13 .
16. A surveillance area comprising a camera surveillance system according to claim 15 .
17. A vehicle comprising an image logging system according to claim 13 .
18. A method of logging input data received from a data source to a data storage memory arranged to store a plurality of data at a plurality of data storage locations, the method comprising:
repeatedly receiving input data having a temporal input data resolution from the data source and
writing newly received input data into the data storage memory, the writing comprising:
writing the newly received input data at the temporal input data resolution,
if the data storage memory comprises recent data: keeping the recent data at the temporal input data resolution in the data storage memory, and
if the data storage memory comprises old data: overwriting part of the old data with at least part of the newly received input data while keeping another part of the old data in the data storage memory at a first temporal aged data resolution,
the recent data corresponding to input data previously written into the data storage memory and satisfying a pre-determined recent age criterion,
the old data corresponding to input data previously written into the data storage memory and satisfying a first pre-determined age criterion
the first temporal aged data resolution being lower than the temporal input data resolution, and
the first pre-determined age criterion being associated with input data having a higher age than input data satisfying the pre-determined recent age criterion.
19. A computer program product comprising instructions stored at a non-transitory medium for causing a programmable apparatus to perform a method of logging input data received from a data source to a data storage memory arranged to store a plurality of data at a plurality of data storage locations as claimed in claim 18 .
20. A non-transitory tangible computer readable storage medium comprising data loadable in a programmable apparatus, the data representing instructions executable by the programmable apparatus, said instructions comprising logging instructions for logging input data received from a data source to a data storage memory arranged to store a plurality of data at a plurality of data storage locations, the logging instructions comprising:
one or more receive instructions for receiving input data having a temporal input data resolution from the data source; and
one or more write instructions for writing newly received input data into the data storage memory, the writing comprising:
writing the newly received input data at the temporal input data resolution,
if the data storage memory comprises recent data: keeping the recent data at the temporal input data resolution in the data storage memory, and
if the data storage memory comprises old data: overwriting part of the old data with at least part of the newly received input data while keeping another part of the old data in the data storage memory at a first temporal aged data resolution,
the recent data corresponding to input data previously written into the data storage memory and satisfying a pre-determined recent age criterion,
the old data corresponding to input data previously written into the data storage memory and satisfying a first pre-determined age criterion,
the first temporal aged data resolution being lower than the temporal input data resolution, and
the first pre-determined age criterion being associated with input data having a higher age than input data satisfying the pre-determined recent age criterion.