Abstract
A method for detecting a water ingress into an interior of a housing, which is sealed against the surroundings, including the following steps: detecting a temperature of the air in the interior; detecting a relative air humidity in the interior; and detecting a water ingress as a function of the detected temperature and of the detected relative air humidity.
Claims
1. A method for detecting a water ingress into an interior of a housing, which is sealed against a surroundings, the method comprising the following steps: detecting a temperature of air in the interior of the housing; detecting a relative air humidity in the interior of the housing; detecting a water ingress into the interior of the housing as a function of a chronological change rate of a difference between the detected temperature and a dew point ascertained as a function of the detected relative air humidity and of the detected temperature, wherein based on the detected water ingress, performing at least one of the following: automatically establishing a service appointment using a radio contact to a server device and displaying the service appointment; and releasing a drying agent by opening a closing device situated in the interior of the housing.
2. The method as recited in claim 1, wherein the detection of the water ingress takes place when the difference and/or the change rate of the difference exceeds a static or dynamic threshold value in each case.
3. The method as recited in claim 1, further comprising the following step: displaying information regarding the water ingress as a function of the detection of the water ingress.
4. The method as recited in claim 1, further comprising the following step: adapting an electrical charging or discharge current of a current source by switching off of the current flow, which is situated in the interior of the housing, as a function of the detected water ingress.
5. The method as recited in claim 4, wherein the current source is a battery.
6. The method as recited in claim 1, further comprising the following step: storing an error code in an electronic memory as a function of the detected water ingress.
7. The method as recited in claim 1, further comprising the following step: changing a service interval of a vehicle as a function of the detected water ingress.
8. An electronic circuit configured to detect a water ingress into an interior of a housing, which is sealed against a surroundings, the electronic circuit configured to: detect a temperature of air in the interior of the housing; detect a relative air humidity in the interior of the housing; detect a water ingress into the interior of the housing as a function of a chronological change rate of a difference between the detected temperature and a dew point ascertained as a function of the detected relative air humidity and of the detected temperature, store an error code in an electronic memory as a function of the detected water ingress, wherein the electronic circuit is additionally configured to activate an electric motor of an electric bicycle for driving the electric bicycle.
9. A housing which houses an electronic circuit, the electronic circuit configured to detect a water ingress into an interior of a housing, which is sealed against a surroundings, the electronic circuit configured to: detect a temperature of air in the interior of the housing; detect a relative air humidity in the interior of the housing; and detect a water ingress into the interior of the housing as a function of a chronological change rate of a difference between the detected temperature and a dew point ascertained as a function of the detected relative air humidity and of the detected temperature, wherein the housing is a housing of a display of a vehicle, or of a battery of the vehicle, or of a drive unit of the vehicle, wherein based on the detected water ingress, performing at least one of the following: automatically establishing a service appointment using a radio contact to a server device and displaying the service appointment; and releasing a drying agent by opening a closing device situated in the interior of the housing.
10. A vehicle including at least one housing which houses an electronic circuit, the electronic circuit configured to detect a water ingress into an interior of a housing, which is sealed against a surroundings, the electronic circuit configured to: detect a temperature of air in the interior of the housing; detect a relative air humidity in the interior of the housing; and detect a water ingress into the interior of the housing as a function of a chronological change rate of a difference between the detected temperature and a dew point ascertained as a function of the detected relative air humidity and of the detected temperature, wherein the housing is a housing of a display of a vehicle, or of a battery of the vehicle, or of a drive unit of the vehicle; and wherein the vehicle is an electric bicycle, wherein based on the detected water ingress, performing at least one of the following: automatically establishing a service appointment using a radio contact to a server device and displaying the service appointment; and releasing a drying agent by opening a closing device situated in the interior of the housing.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 shows a housing.
(2) FIG. 2 shows an electric bicycle including the housing.
(3) FIG. 3 shows a flow chart of the method for detecting the water ingress.
(4) FIG. 4a shows a diagram for the profile of the ascertained difference without a water ingress.
(5) FIG. 4b shows a diagram for the profile of the ascertained difference in the case of a water ingress.
(6) FIG. 5a shows a diagram for the profile of the change rate without a water ingress.
(7) FIG. 5b shows a diagram for the profile of the change rate in the case of a water ingress.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
(8) In FIG. 1, a housing 100 is illustrated, for example of a drive unit 230 of an electric bicycle. Housing 100 includes an interior 101, a humidity sensor 110, and a temperature sensor 120. Housing 100 further includes an electronic circuit 400 for carrying out a method according to the present invention. Electronic circuit 400 may be advantageously additionally configured to activate an electric motor of an electric bicycle for the purpose of driving the electric bicycle. Furthermore, electrical interfaces 130 are illustrated at an outer wall 102 of housing 100. Moreover, housing 100 includes display means 140, for example LED elements. Housing 100 is sealed with the aid of at least one polymer seal 150 against a water ingress from surroundings 190. Housing 100 includes, for example, a cover 103 and a basic unit 104, polymer seals 150 being situated, for example, between cover 103 and basic unit 104 as well as at electrical interfaces 130. Housing 100 may be subject to damage or leakages due to an impact load or long-term material fatigue, for example of polymer seals 150, thus resulting in short-term or long-term water ingress. Furthermore, an additionally closed space 198 including a drying agent 199 is optionally provided in housing 100, space 198 being opened in the case of detected water ingress and drying agent 199 being released. Optionally and preferably, housing 100 includes a pressure balance element (not illustrated in FIG. 1) that balances the atmospheric pressure between interior 101 of the housing and surroundings 190. The optional pressure balance element may be advantageously used to improve a sealing effect of polymer seals 150.
(9) In FIG. 2, an electric bicycle 200 is illustrated including a battery 220, a display 210, and a drive unit 230, which may include an electronic circuit or a control unit, for example. Battery 220 and/or display 210 and/or drive unit 230 have a housing 100 according to the present invention.
(10) Housing 100 may be for example alternatively used in other technical applications, for example housing 100 may include a safety-relevant electrical circuit of a vehicle. For example, the housing is a housing of a power electronic device of an electric vehicle, a housing 100 of a control unit of a steering system of a vehicle, a housing 100 of a battery or of a battery management system of a vehicle, or a housing of a power tool.
(11) In FIG. 3, a flow chart of the method for detecting 330 a water ingress into housing 100 is illustrated. The method has a step 310, in which an instantaneous temperature in interior 101 of housing 100 is detected. In step 320, a relative air humidity of the air is detected in interior 101 of housing 100. Subsequently, a detection of the water ingress takes place in step 330 as a function of the detected temperature and of the detected relative air humidity. Detection 330 of the water ingress takes place in particular as a function of an ascertained difference Δ between detected temperature T and a dew point τ ascertained as a function of detected relative air humidity φ and as a function of detected temperature T. The detection of the water ingress takes place, for example, when this ascertained difference Δ falls below or exceeds a threshold value. Alternatively and preferably, detection 330 of the water ingress takes place as a function of a chronological change rate {dot over (Δ)} of ascertained difference Δ in particular when chronological change rate {dot over (Δ)} of difference Δ exceeds a static or dynamic threshold value S. Threshold value S is preferably dynamic. Threshold value S is advantageously ascertained as a function of one or multiple static performance figure(s) of chronological change rate {dot over (Δ)} of difference Δ, for example of a mean value and/or of a standard deviation and/or of a multiple of the standard deviation. When ascertaining the dynamic threshold value, the statistical characteristics of chronological change rate {dot over (Δ)} of difference Δ are advantageously ascertained within a time period prior to the instantaneous point τ n time or glidingly. In a step 340, water ingress information is optionally displayed to a user, for example with the aid of display means 140, as a function of detection 330 of the water ingress. Moreover, an optional adaptation 350 of an electrical charging or discharge current of a current source or battery, which is situated in the interior of housing 100, may be carried out as a function of the detected water ingress. Adaptation 350 of an electrical charging or discharge current may take place until the current source is switched off with the aid of an electrical switch. An optional storage 360 of an error code in an electronic memory may be further carried out as a function of the detected water ingress, the electronic memory being advantageously also situated in housing 100 and read out with the aid of interface 130, for example. A change 370 of a service interval of a vehicle further optionally takes place as a function of the water ingress detected in step 330. In one optional refinement, a service appointment is established and in particular displayed to the user in optional step 380 as a function of the detected water ingress with the aid of a radio contact to a server device. Furthermore, a release 390 of a drying agent 199 in interior 101 of housing 100 may be optionally provided as a function of the detected water ingress.
(12) FIGS. 4a and 4b each show a diagram of the chronological profile of difference Δ, ascertained for detection 330 of the water ingress, between instantaneous temperature T detected in step 310 and dew point τ ascertained as a function of relative air humidity ∠ detected in step 320 and as a function of temperature T detected in step 310. Ascertained difference Δ has unit [K]. The time is indicated in hours or [h]. The profile of ascertained difference Δ shows natural oscillations or a noise, but no significant deviations, since there is no water ingress. In FIG. 4b, a water ingress 401 into housing 100 takes place at point in time t0 or after approximately 45 minutes, whereby ascertained difference Δ considerably drops. The water ingress may consequently be reliably detected as a result of this ascertained difference Δ, as soon as ascertained difference Δ exceeds or falls below a static or dynamic threshold value, for example. Ascertained difference Δ markedly decreases, for example, even if an ingress of only a small quantity of water takes place into housing 100, since even a small quantity of water always shifts the equilibrium between evaporation and condensation.
(13) FIGS. 5a and 5b each show a diagram of the chronological profile of chronological change rate {dot over (Δ)} of difference Δ, ascertained for detection 330 of the water ingress, between instantaneous temperature T detected in step 310 and dew point τ ascertained as a function of relative air humidity ∠ detected in step 320 and as a function of instantaneous temperature T detected in step 310. FIG. 5a corresponds to FIG. 4a (i.e., no water ingress) and FIG. 5b corresponds to FIG. 4b (i.e., with water ingress). Ascertained change rate {dot over (Δ)} has unit [K/h]. The time is indicated in hours h. The profile of ascertained change rate {dot over (Δ)} shows oscillations or a noise in FIG. 5a, but no significant deviations, since there is no water ingress. In FIG. 5b, a water ingress 501 into housing 100 takes place at point τ n time t0 or after approximately 45 minutes, whereby an amount of ascertained change rate {dot over (Δ)} increases. Water ingress 501 may consequently be detected rapidly and reliably with the aid of this ascertained change rate A, for example upon exceedance of a static threshold value or preferably upon exceedance of a dynamic threshold value.
