US 12,135,271 B2
Sensor device and particulate matter sensor
Soeren Sofke, Tübingen (DE); and Tarek Zaki, Munich (DE)
Assigned to Robert Bosch GmbH, Stuttgart (DE); and TRUMPF Photonic Components GmbH, Ulm (DE)
Filed by Robert Bosch GmbH, Stuttgart (DE); and TRUMPF Photonic Components GmbH, Ulm (DE)
Filed on Sep. 24, 2021, as Appl. No. 17/485,112.
Claims priority of application No. 10 2020 127 377.0 (DE), filed on Oct. 16, 2020.
Prior Publication US 2022/0120663 A1, Apr. 21, 2022
Int. Cl. G01N 15/1429 (2024.01); G01N 15/14 (2024.01)
CPC G01N 15/1429 (2013.01) [G01N 15/1425 (2013.01); G01N 2015/1486 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A particulate matter sensor having a sensor device comprising
at least one sensor unit comprising at least one laser unit for a generation of at least one laser beam and comprising at least one photodetector for a detection of laser beams,
a switch element which is configured to process detected laser beams into sensor signals,
a control unit which is configured, in a continuous operation state, to
actuate the sensor unit and the switch element for an operation of the sensor unit and the switch element in alternating switch-on intervals and switch-off intervals,
limit the switch-on intervals of the sensor unit and the switch-on intervals of the switch element to a duration of maximally 60 s,
limit the switch-on intervals of the sensor unit and the switch-on intervals of the evaluation unit all to a same duration, and
limit the switch-off intervals of the sensor unit and the switch-off intervals of the switch element all to a same duration,
wherein the switch element is configured to generate in the switch-on intervals the sensor signals as moving averages from data, which were captured and stored by the photodetector in the last four different switch-on intervals of the sensor unit,
and wherein in the switch-on intervals of the switch element, the switch element generates sensor signals from the fourth switch-on interval of the switch element on, with the first three sensor signals being implemented as zero signals when a minimum number of four switch-on intervals of the sensor unit have not been gone through yet.