Gardening device with rainwater detection sensor

Abstract

There is provided a sensor unit for sensing raindrops on an outer surface of a device, in particular a horticultural device, the sensor unit being mounted inside the horticultural device. The sensor unit has a first electrode and a second electrode between which a primary electric field is generated. The primary electric field includes a primary electric field line. The sensor unit is characterized in that the sensor unit further comprises a third electrode disposed between the first electrode and the second electrode. The first electrode and the third electrode generate a secondary electric field between the first electrode and the third electrode. The secondary electric field comprises a secondary electric field line. A secondary electric field line of the secondary electric field further guides a primary electric field line of the primary electric field toward an outer surface of the gardening device.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a garden appliance, in particular a garden appliance with a rain detection sensor. BACKGROUND

[0002] Precipitation sensors are used, for example, for building automation, for example to trigger window and canopy controls when precipitation begins. It is important to reliably and early detect a rain event and to recognize new precipitation events in changeable weather. For example, a roof window that is opened after a shower must also be closed again when it rains again. Precipitation sensors can also be used to control irrigation systems and to monitor items such as laundry hung outside. Precipitation sensors are also part of weather stations.

[0003] In addition to mechanical and optical rain sensors, purely electronic precipitation sensors are particularly known which work according to a capacitive or resistive measurement method. Using two electrodes as a sensor surface, the capacitance or resistance between these two electrodes is measured and compared with a threshold value to be determined. A disadvantage of resistive sensors is that open, unprotected electrodes must be used, which deteriorate over time through corrosion and through electrolysis when direct current is used. The electrodes of capacitive sensors can be insulated with a layer of varnish or foil and are thus protected from corrosion. The capacitance can be determined by measuring the voltage in an LC resonance circuit or the charging / discharging time.

[0004] An example is provided by European patent application EP 4 143 973 Al (hereinafter referred to as the '973 reference). The '973 reference discloses a rain detection device for sensing raindrops on a surface. At least one sensor unit has at least one capacitive sensor element. The sensor element is designed and / or arranged such that a capacitance property of the sensor element changes based on an object contacting the surface. At least one evaluation unit is designed to detect raindrops on the surface based on a differential signal of the sensor element. The evaluation unit is designed to detect raindrops on the surface based on a symmetry property of the differential signal, more specifically with respect to a zero point. SUMMARY

[0005] It is an object of the present invention to provide a humidity measuring device which is able to reliably measure the presence of raindrops on a surface and thus to measure the humidity on a surface.

[0006] According to an aspect of the application, a sensor unit for sensing raindrops on an outer surface of a device is provided, the sensor unit being mounted inside the device. The device is in particular a horticulture device. The sensor unit comprises a first electrode and a second electrode. The first electrode and the second electrode generate a primary electric field between them. The primary electric field comprises primary electric field lines. The sensor unit is characterized in that the sensor unit further comprises a third electrode arranged between the first electrode and the second electrode. The first electrode and the third electrode generate a secondary electric field between the first electrode and the third electrode. The secondary electric field comprises secondary electric field lines. The secondary electric field lines of the secondary electric field further direct the primary electric field lines of the primary electric field towards the outer surface of the device.

[0007] With the primary electric field lines being further directed towards the outer surface of the device, a larger amount of primary electric field lines is present near or outside the outer surface of the device. Thereby, the amount of rain or raindrops can be measured in a more accurate way. Furthermore, the presence of the primary electric field lines outside the outer surface of the device or outside the housing enables a more reliable measurement of raindrops.

[0008] The horticulture device according to the application can denote a device used in a garden for performing a horticulture task. Exemplary horticulture devices can be for example a watering device such as a sprinkler, a sprayer or a water gun, an automatic watering device, an automatic lawnmower or a pump.

[0009] According to an exemplary embodiment of the application, the secondary electric field lines of the secondary electric field further direct the primary electric field lines of the primary electric field away from the first electrode and / or the second electrode. Directing the primary electric field lines of the primary electric field further away from the first electrode and / or the second electrode according to the application can denote that the maximum distance between the primary electric field lines and the first electrode and / or the second electrode is directed further away from the first electrode and / or the second electrode. In particular, the primary electric field lines or the secondary electric field lines extend in an arc shape between the respective electrodes. Furthermore, the distance between the electric field lines and the respective electrodes can be measured perpendicular to the respective electrodes.

[0010] Thereby, a more reliable measurement of the presence of any rain or raindrops on the housing of the device can be provided.

[0011] According to an exemplary embodiment of the application, the second electrode is placed at a first distance from the first electrode and the third electrode is placed at a second distance from the first electrode. The distance between the first electrode and the second electrode or the first electrode and the third electrode is carefully chosen to create the most appropriate combination of the primary electric field and the secondary electric field. Thereby, a reliable measurement of the presence of any rain or raindrops on the housing of the device can be provided.

[0012] The first distance is measured from a middle of the first electrode to a middle of the second electrode. Similarly, the second distance is measured from the middle of the first electrode to a middle of the third electrode.

[0013] The middle of the first electrode, the middle of the second electrode and the middle of the third electrode are the middle of the length of the respective electrode seen in a cross-section perpendicular to the main surface of the respective electrode. Thus, when the third electrode is positioned in the middle between the first electrode and the second electrode, the second distance is essentially half of the first distance.

[0014] According to an exemplary embodiment of the present application, the first distance is essentially twice the second distance. This position arrangement indicates that the third electrode is positioned equidistant to the first electrode and the second electrode. In other words, this positioning is such that the third electrode, in particular the middle of the third electrode, is positioned in the middle between the first electrode, in particular the middle of the first electrode, and the second electrode, in particular the middle of the second electrode. Thereby, the primary electric field lines have a greater or steeper gradient near the main surface of the first electrode than the secondary electric field lines. Thus, the secondary electric field lines push the primary electric field lines further away from the first electrode. Thereby, the area in which the presence of any rain or raindrops on the housing of the device can be measured can be increased. Furthermore, the area in which the sensor unit inside the housing can be positioned can be increased, such that the sensor unit does not have to be mounted to the surface on which the presence of rain is measured.

[0015] According to an exemplary embodiment of the present application, the first distance is less than twice the second distance. This position arrangement indicates that the third electrode, in particular the middle of the third electrode, is positioned closer to the second electrode, in particular the middle of the second electrode, than the first electrode, in particular the middle of the first electrode. This particular arrangement can be used when the sensor unit is mounted on or near a surface on which the presence of rain or raindrops is measured. Thereby, the accuracy of the measurement of the presence of rain or raindrops on the nearby surface can be improved in an easy and efficient way.

[0016] According to an exemplary embodiment of the present application, the first distance is less than twice the second distance. This position arrangement indicates that the third electrode, in particular the middle of the third electrode, is positioned closer to the second electrode, in particular the middle of the second electrode, than the first electrode, in particular the middle of the first electrode. Thereby, the primary electric field lines have a further increased gradient near the main surface of the first electrode than the secondary electric field lines. Thus, the secondary electric field lines push the primary electric field lines even further away from the first electrode. Thereby, the housing can have an increased wall thickness or the sensor unit can be positioned further away from the surface on which the presence of rain or raindrops is measured or further inside the housing. Thus, the area of application of the sensor unit can be increased.

[0017] According to an exemplary embodiment of the present application, the first electrode forms an excitation plate and / or the second electrode forms a first sensing plate and / or the third electrode forms a second sensing plate. Thus, there are two sets of electric field generation, namely a primary electric field between the first electrode and the second electrode and a secondary electric field between the first electrode and the third electrode. The primary electric field and the secondary electric field interact with each other such that the secondary electric field lines direct the primary electric field lines further away from the three electrodes and thereby towards the outer surface of the device. Thereby, the area in which the presence of any rain water or rain drops on the housing of the device can be measured is increased. Thus, the accuracy of the rain water or rain drop detection can be improved.

[0018] According to an exemplary embodiment of the present application, at least one of the first electrode, the second electrode and the third electrode is a planar electrode. The planar shape of the electrodes helps to keep a compact structure and enables to reduce the size of the sensor unit as a whole. Thus, a compact sensor unit can be provided.

[0019] According to an exemplary embodiment of the present application, the first electrode, the second electrode and the third electrode are arranged in one common plane. Such an arrangement helps to efficiently position the first electrode, the second electrode and the third electrode on a planar surface when assembling the device.

[0020] According to an aspect of the present application, a device comprises a housing having an outer surface and a sensor unit according to any of the described exemplary embodiments, wherein the sensor unit is mounted inside the housing. A horticulture device with a sensor unit mounted inside the housing can measure the presence of rain water or rain drops on the outer surface of the housing in an efficient way.

[0021] According to an exemplary embodiment of the present application, the horticulture device further comprises a PCB (Printed Circuit Board), wherein the sensor unit is mounted on a main surface of the PCB. The PCB enables compact structural details and efficient assembly of the device. Furthermore, the PCB allows the use of standardized parts, thus providing a cost-efficient sensor unit.

[0022] According to an exemplary embodiment of the present application, the sensor unit is mounted inside the housing in direct contact with the housing. The direct contact of the sensor unit with the housing reduces the distance between the electrodes and the outer surface of the housing. Thus, the rain water detection can be more accurate and / or the area in which the presence of rain water or rain drops can be detected can be increased.

[0023] According to an exemplary embodiment of the present application, the horticulture device is at least one of a watering device, an isohyet sprinkler, a robotic lawnmower and a watering computer. Thereby, the irrigation schedule or the mowing can be synchronized with the rain water detection results. Thus, the water supply can be controlled accordingly. This can save a lot of water and electricity and improve the plant health based on optimized irrigation.

[0024] According to an aspect of the application, a method of sensing raindrops on an outer surface of a horticulture device is provided. The method comprises providing a sensor unit having a first electrode and a second electrode. The method comprises generating a primary electric field between the first electrode and the second electrode, wherein the primary electric field comprises primary electric field lines. The method is characterized in that the method comprises providing a third electrode between the first electrode and the second electrode. The method further comprises generating a secondary electric field between the first electrode and the third electrode, wherein the secondary electric field comprises secondary electric field lines. The method comprises directing the primary electric field lines of the primary electric field further towards the outer surface of the device by the secondary electric field lines of the secondary electric field.

[0025] The method aims to direct the primary electric field lines of the primary electric field further towards the outer surface of the device. Hence, a relatively large proportion of the primary electric field lines is present near or outside the outer surface of the horticulture device. This contributes to measuring the amount of rain or raindrops in a more accurate manner. Furthermore, the area in which the presence of rain or raindrops can be measured can be increased. The presence of the primary electric field lines outside the outer surface of the horticulture device or outside the housing facilitates a more reliable measurement of raindrops, as the primary electric field lines are present extensively in an area in which raindrops can be present.

[0026] Before the application is discussed in detail with reference to the drawings, the application will be summarized in a simple way. A rain sensor is located directly in a horticulture device to detect rain and to pause irrigation. In a well-known capacitive humidity sensor, two opposing or planar electrodes are typically used to determine the dielectric between them. However, with this arrangement, the distance to the measuring medium is decisive. A particular challenge is to place the electrodes behind the housing and to measure through the housing, so that the electrical parts can be completely isolated from the environment. As the thickness of the housing increases, the capacitance of the capacitor is mainly determined by the housing itself and is no longer influenced by external moisture. According to the application, the secondary electric field lines of the third electrode mainly propagate in the housing, thereby pushing the primary electric field lines of the outer electrodes further away into the medium to be measured. Hence, depending on the setup, the sensitivity can be increased, in particular by a factor of more than one, and a more accurate moisture / rain measurement can be made.

[0027] Other characteristics and aspects of the application will be apparent from the following description and the attached drawings. BRIEF DESCRIPTION OF DRAWINGS

[0028] The application will be described in more detail with reference to the drawings, in which:

[0029] Figure 1 a perspective view of a horticulture device is illustrated according to an example embodiment of the present disclosure;

[0030] Figure 2 a schematic view of a horticulture device is illustrated according to an example embodiment of the present disclosure; and

[0031] Figure 3 The steps of a method for sensing raindrops on the outer surface of a gardening apparatus according to an exemplary embodiment of the present disclosure are illustrated. Detailed Implementation

[0032] The invention will now be described more fully with reference to the accompanying drawings, which illustrate exemplary embodiments of the invention incorporating one or more aspects thereof. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make this disclosure comprehensive and complete, and to fully convey the scope of the invention to those skilled in the art. For example, one or more aspects of the invention may be used in other embodiments and even other types of structures and / or methods. In the drawings, the same numerals denote the same elements.

[0033] Certain terms are used herein for convenience only and are not intended to limit the invention. For example, “upper,” “lower,” “front,” “rear,” “side,” “longitudinal,” “lateral,” “transverse,” “upward,” “downward,” “forward,” “backward,” “left,” “right,” “horizontal,” “vertical,” “upward,” “inner,” “outer,” “inward,” “outer,” “top,” “bottom,” “higher,” “above,” “below,” “center,” “middle,” “central,” “between,” “end,” “adjacent,” “near,” “near,” “far,” “remote,” “radial,” “circumferential,” etc., describe only the configurations shown in the figures. In practice, components may be oriented in any direction, and therefore the terms should be understood to cover such variations unless otherwise specified.

[0034] Figure 1 A perspective view of a gardening device 100, which is a sprinkler, specifically a contour sprinkler, is shown.

[0035] The gardening apparatus 100 has a housing 102. The housing 102 has an outer surface 104. The outer surface 104 is exposed to various environmental elements, such as dust, sunlight, and rainfall. The gardening apparatus 100 can be used in a variety of applications, including control tasks or any other suitable purpose. The housing 102 houses various components. However, only those components relevant to the context of this disclosure will be discussed. It should be noted that the housing 102 may include components other than those described in this disclosure. The gardening apparatus 100 includes a sensor unit 106 housed within the gardening apparatus 100.

[0036] Figure 2A schematic view of a horticulture device 100 is shown. The horticulture device comprises a sensor unit 106. The horticulture device 100 further comprises a PCB 108. The sensor unit 106 is mounted on a main surface 110 of the PCB 108. Furthermore, the sensor unit 106 is mounted inside the housing 102 in direct contact with an opposite surface of the outer surface 104 of the housing 102. In other words, the sensor unit 106 is sandwiched between the PCB 108 and the housing 102. The sensor unit 106 comprises a first electrode 202 and a second electrode 204. The first electrode 202 and the second electrode 204 generate a primary electric field Fl between the first electrode 202 and the second electrode 204. The primary electric field Fl comprises primary electric field lines. The second electrode 204 is placed at a first distance Dl from the first electrode 202. The first distance Dl is measured from a middle of the first electrode 201 to a middle of the second electrode 202.

[0037] The horticulture device 100 further comprises a third electrode 206. Seen in a direction perpendicular to the outer surface 104, the third electrode 206 is arranged between the first electrode 202 and the second electrode 204. The third electrode 206 is placed at a second distance D2 from the first electrode 202. The first electrode 202 and the third electrode 206 generate a secondary electric field F2 between the first electrode 202 and the third electrode 206. The secondary electric field F2 comprises secondary electric field lines. The second distance D2 is measured from a middle of the first electrode 201 to a middle of the third electrode 203.

[0038] Figure 2 The first electrode 202, the second electrode 204 and the third electrode 206 are schematically shown arranged next to each other. In the example embodiment shown, the first electrode 202, the second electrode 204 and the third electrode 206 are arranged in a straight line. Figure 2 In the example embodiment shown, the first distance Dl is substantially twice the second distance D2. In another example embodiment, the first distance Dl is less than twice the second distance D2. In yet another example embodiment, the first distance Dl is more than twice the second distance D2.

[0039] Figure 2 The primary electric field lines of the primary electric field Fl and the secondary electric field lines of the secondary electric field F2 are also shown. The secondary electric field lines of the secondary electric field F2 push the primary electric field lines of the primary electric field Fl further towards the outer surface 104 of the horticulture device 100. The secondary electric field lines of the secondary electric field F2 thereby direct the primary electric field lines of the primary electric field Fl further away from the first electrode 202, the second electrode 204 and the third electrode 203. This allows the sensor unit 106 to detect raindrops 208 on the outer surface 104 of the horticulture device 100.

[0040] The first electrode 202 forms an excitation plate. The second electrode 204 forms a first sensing plate and the third electrode 206 forms a second sensing plate. The first electrode 202, the second electrode 204 and the third electrode 206 together provide a sensing arrangement for raindrops on the outer surface 104 of the horticulture device 100. As will be clear from Figure 2 It will be clear that the first electrode 202, the second electrode 204 and the third electrode 206 are each formed as a planar electrode. Further, the first electrode 202, the second electrode 204 and the third electrode 206 are together arranged in one common plane.

[0041] Figure 3 A method 300 of sensing raindrops on the outer surface 104 of the horticulture device 100 is depicted. The method 300 comprises providing, in step 302, the sensor unit 106 comprising the first electrode 202 and the second electrode 204. The method 300 comprises generating, in step 304, a primary electric field Fl between the first electrode 202 and the second electrode 204. The primary electric field Fl comprises primary electric field lines. The method 300 is characterized in that the method 300 comprises providing, in step 306, the third electrode 206 between the first electrode 202 and the second electrode 204. The method 300 comprises generating, in step 308, a secondary electric field F2 between the first electrode 202 and the third electrode 206. The secondary electric field F2 comprises secondary electric field lines. The method 300 further comprises directing, in step 310, the primary electric field lines of the primary electric field Fl further towards the outer surface 104 of the horticulture device 100, wherein the secondary electric field lines of the secondary electric field F2 push the primary electric field lines away from the first electrode 201, the second electrode 202 and the third electrode 203.

[0042] In the drawings and specification, there have been disclosed exemplary embodiments and examples of the application, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the application being set forth in the following claims.

[0043] List of elements

[0044] 100 horticulture device

[0045] 102 housing

[0046] 104 outer surface

[0047] 106 sensor unit

[0048] 108 PCB

[0049] 110 main surface

[0050] 202 first electrode

[0051] 204 second electrode

[0052] 206 third electrode

[0053] 208 raindrop

[0054] 300 method

[0055] 302 step

[0056] 304 step

[0057] 306 step

[0058] 308 step

[0059] 310 step

[0060] F1 first electric field

[0061] F2 second electric field

[0062] D1 first distance

[0063] D2 second distance.

Claims

1. A sensor unit (106) for sensing raindrops (208) on the outer surface (104) of a device (100), specifically a gardening device (100), wherein the sensor unit (106) is installed inside the gardening device (100), wherein the sensor unit (106) comprises: A first electrode (202) and a second electrode (204) generate a primary electric field (F1) between the first electrode (202) and the second electrode (204), wherein the primary electric field (F1) includes primary electric field lines; Its features are: The sensor unit (106) further includes a third electrode (206) disposed between the first electrode (202) and the second electrode (204). The first electrode (202) and the third electrode (206) generate a secondary electric field (F2) between the first electrode (202) and the third electrode (206). The secondary electric field (F2) includes secondary electric field lines, and The secondary electric field lines of the secondary electric field (F2) further guide the primary electric field lines of the primary electric field (F1) toward the outer surface (104) of the gardening device (100).

2. The sensor unit (106) according to claim 1. The secondary electric field lines of the secondary electric field (F2) guide the primary electric field lines of the primary electric field (F1) further away from the first electrode (202) and / or the second electrode (204).

3. The sensor unit (106) according to claim 1 or 2. in: The second electrode (204) is placed at a first distance (D1) from the first electrode (202), and The third electrode (206) is placed at a second distance (D2) from the first electrode (202).

4. The sensor unit (106) according to claim 3. The first distance (D1) is essentially twice the second distance (D2).

5. The sensor unit (106) according to claim 3. The first distance (D1) is less than twice the second distance (D2).

6. The sensor unit (106) according to claim 3. The first distance (D1) is more than twice the second distance (D2).

7. The sensor unit (106) according to any one of the preceding claims. Wherein the first electrode (202) forms an excitation plate, and / or The second electrode (204) forms the first sensing plate, and / or The third electrode (206) forms the second sensing plate.

8. The sensor unit (106) according to any one of the preceding claims. At least one of the first electrode (202), the second electrode (204), and the third electrode (206) is a planar electrode.

9. The sensor unit (106) according to any one of the preceding claims. The first electrode (202), the second electrode (204), and the third electrode (206) are arranged in a common plane.

10. A gardening apparatus (100), the gardening apparatus comprising A housing (102) having an outer surface (104), and The sensor unit (106) according to any one of the preceding claims. The sensor unit (106) is installed inside the housing (102).

11. The gardening apparatus (100) according to claim 10, further comprising: A printed circuit board (108), wherein the sensor unit (106) is mounted on the main surface (110) of the printed circuit board (108).

12. The gardening apparatus (100) according to claim 10 or 11. The sensor unit (106) is installed inside the housing (102) and is in direct contact with the housing (102).

13. The gardening apparatus (100) according to any one of claims 10 to 12. The gardening device (100) is a watering device, a contour sprinkler, a robotic lawnmower, or a watering computer.

14. A method (300) for sensing raindrops (208) on the outer surface (104) of a gardening apparatus (100), the method (300) comprising: A sensor unit (106) including a first electrode (202) and a second electrode (204) is provided; A primary electric field (F1) is generated between the first electrode (202) and the second electrode (204), wherein the primary electric field (F1) includes primary electric field lines; Its features are: A third electrode (206) is disposed between the first electrode (202) and the second electrode (204). A secondary electric field (F2) is generated between the first electrode (202) and the third electrode (206), wherein the secondary electric field (F2) includes secondary electric field lines; and The primary electric field lines of the primary electric field (F1) are further guided towards the outer surface (104) of the gardening device (100) by the secondary electric field lines of the secondary electric field (F2).

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