Rain detection device, garden appliance having the rain detection device, and method for sensing rain drops on a surface by means of a rain detection device
AssigneeRobert Bosch GmbH
InventorsPaul Abbott, Chris Wild
Life of this patent
Estimating the term…
Abstract
A rain detection device for sensing rain drops on a surface includes at least one sensor unit and at least one evaluation unit. The sensor unit includes at least one capacitive sensor element. The sensor element is configured such that a capacitance characteristic of the sensor element changes based on an object contacting the surface. The evaluation unit is configured to detect rain drops on the surface based on a differential signal of the sensor element. The evaluation unit is configured to detect a rain drop on the surface based on a symmetry characteristic of the differential signal with respect to a zero point.
Claims12
A rain detection device for sensing rain drops on a surface, comprising:
- at least one sensor unit including at least one capacitive sensor element, the at least one capacitive sensor element configured such that a capacitance characteristic value of the at least one capacitive sensor element changes depending on an object contacting the surface;
- and
- at least one evaluation unit configured to detect rain drops on the surface depending on a differential signal from the at least one capacitive sensor element, the at least one evaluation unit configured to detect a rain drop on the surface depending on a symmetry characteristic value of the differential signal,
- wherein the symmetry characteristic value is formed as a ratio of a positive weighting characteristic value of the differential signal and a negative weighting characteristic value of the differential signal, and
- wherein the at least one evaluation unit is configured to detect the rain drop on the surface depending on a limit value or a limit range of the symmetry characteristic value being exceeded.
A garden appliance, comprising:
- at least one rain detection device including (i) at least one sensor unit including at least one capacitive sensor element, the at least one capacitive sensor element configured such that a capacitance characteristic value of the at least one capacitive sensor element changes depending on an object contacting the surface, and (ii) at least one evaluation unit configured to detect rain drops on the surface depending on a differential signal from the at least one capacitive sensor element, the at least one evaluation unit configured to detect a rain drop on the surface depending on a symmetry characteristic value of the differential signal,
- wherein the symmetry characteristic value is formed as a ratio of a positive weighting characteristic value of the differential signal and a negative weighting characteristic value of the differential signal, and
- wherein the at least one evaluation unit is configured to detect the rain drop on the surface depending on a limit value or a limit range of the symmetry characteristic value being exceeded.
A method for sensing rain drops on a surface using a rain detection device, comprising:
- sensing a capacitance characteristic value using at least one capacitive sensor element of at least one sensor unit of the rain detection device;
- and
- detecting a rain drop on the surface depending on a symmetry characteristic value of a differential signal of the at least one capacitive sensor element using at least one evaluation unit of the rain detection device,
- wherein the symmetry characteristic value is formed as a ratio of a positive weighting characteristic value of the differential signal and a negative weighting characteristic value of the differential signal, and
- wherein the at least one evaluation unit is configured to detect the rain drop on the surface depending on a limit value or a limit range of the symmetry characteristic value being exceeded.
Dependencies are inferred from the claim text.