Monitoring device for optically monitoring surfaces of an object, in particular a sauna heater

Abstract

The invention relates to a monitoring device for optically monitoring surfaces of an object on which items can be deposited. The monitoring device has: at least one optical sensor, which is / are designed to optically detect at least sub-regions of the surface, and a processing device, which is connected to the at least one optical sensor for communication purposes and which is designed to ascertain or store at least one reference profile of the surface and to process measurement values detected during a monitoring process such that the processing device detects a deviation of a currently measured profile from the reference profile and outputs a signal on the basis of the detected change in order to communicate that an item is located on the surface and / or in order to prevent the operation of the object from being cleared, in particular in the event of a remote-controlled activation request.

Description

[0001] Monitoring device for optical monitoring of surfaces of an object, in particular a sauna heater

[0002] The invention relates to a monitoring device for optically monitoring surfaces of an object on which objects can be placed. In particular, the invention is aimed at monitoring the surfaces of sauna heaters to check whether objects are still lying on the sauna heater when it is (remotely) switched on. This can reduce the risk of fire. Furthermore, other surfaces such as storage areas can be monitored.

[0003] Heated rooms such as saunas, sanariums, or steam baths are widespread. These rooms are heated using heat sources such as a stove, which is usually topped with stones, as these ensure good heat storage and slow heat release into the room. Such rooms are referred to below as saunas. To start heating the room and to control the temperature and, if applicable, the humidity in the room, a control and regulation device is provided. This device receives an interior temperature from temperature sensors located in the room and controls or regulates the heat source based on this.

[0004] Remotely switching on heat sources such as sauna heaters is currently associated with considerable effort, as it is necessary to ensure that no objects are placed on the heat source, as these could catch fire due to the heat source's high temperatures. DE 19 954 075 C1 proposes a safety switching device for switching on the heating of a heated room, which shows a remote switch-on. However, this remote switch-on still depends on a person giving permission directly at the sauna. DE 19 954 075 C1 provides a key switch for this purpose, which communicates with the remote switch-on via a network connection. The heater cannot be switched on without the key switch being operated on site. In many areas, storage areas for materials, packages, processed workpieces, etc.for which there is an active remote monitoring option, but there is still room for improvement.

[0005] It is an object of this invention to provide an automated monitoring possibility for surfaces of an object on which objects can be placed.

[0006] This object is achieved according to the invention by the features of the independent patent claims. Advantageous embodiments are the subject of the dependent claims.

[0007] A monitoring device is proposed for the optical monitoring of surfaces of an object on which objects can be placed, wherein the monitoring device has: at least one optical sensor which is or are configured to optically detect at least partial areas of the surface, and a processing device which is in communication connection with the at least one optical sensor and is configured to determine or store at least one reference profile of the surface and to process measured values ​​recorded during monitoring in such a way that it detects a deviation of a currently measured profile from the reference profile and, depending on the detected change, outputs a signal in order to communicate that an object is located on the surface and / or to prevent release of operation of the object, in particular in the case of a remote-controlled activation request.

[0008] In one embodiment, the processing device is designed to output the signal only after a predetermined time.

[0009] In one embodiment, the output signal is an acoustic signal and / or an optical signal and / or a haptic signal. In one embodiment, the object is a device that is powered by energy, and the output signal revokes the device's authorization to operate the device.

[0010] In one embodiment, the optical sensor is designed to record the measured values ​​continuously or at intervals.

[0011] In one embodiment, it is provided that, in order to initialize the monitoring device, the optical sensor determines a profile of the surface as a reference surface, or wherein a profile of the surface is stored as a reference surface in the processing device, or wherein the processing device processes predetermined information on the reference surface and determines a profile of the surface as a reference surface therefrom.

[0012] In one embodiment, the monitoring device comprises an operating element, the operation of which enables the detection of the reference surface.

[0013] Furthermore, a system comprising a sauna heater and a monitoring device is provided, wherein the monitoring device is arranged and configured to monitor a surface of the sauna heater in such a way that, in the event that it receives a remote-controlled switch-on signal as an activation request and the processing device detects a deviation of a currently measured profile from the reference profile and an exceeding of a predetermined limit value, it outputs a signal in such a way that switching on of the sauna heater is prevented.

[0014] Furthermore, a sauna is provided, comprising the monitoring device or the system comprising a sauna heater and monitoring device.

[0015] Furthermore, a method is provided for the optical monitoring of surfaces of an object on which objects can be placed, by means of a monitoring device, wherein in an initialization step a profile of a reference surface is detected or specified and stored by the processing device, and then, upon a switch-on signal, the current surface is at least partially scanned by means of the at least one optical sensor in such a way that a current profile of the surface is determined, wherein in the event of detection of a change in the reference profile such that a limit value is exceeded, a signal is output to prevent operation of the object and / or to communicate that an object is located on the surface

[0016] Further features and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, with reference to the figures of the drawing, which illustrate details of the invention, and from the claims. The individual features can be implemented individually or in combination in a variant of the invention.

[0017] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings.

[0018] Fig. 1 shows a representation of a monitoring device arranged above an object according to an embodiment of the present invention.

[0019] The invention provides a monitoring device 2 for the optical monitoring of surfaces 10 of an object 1. In this case, it can be provided that in certain situations no additional objects may be placed on the surfaces 10, which is particularly necessary for sauna heaters in order to enable remote-controlled, i.e. unattended, switching on. Remote-controlled switching on is understood to mean any switching on in which there is no direct view of the surface(s) 10 of the object 1, i.e., these are not monitored, i.e., unattended, during switching on. However, a surface 10 can also be monitored to determine whether an object has been placed on it. To achieve this, the monitoring device 2 has at least one optical sensor 20, which is arranged above the surface 10 of the object 1. It can be arranged directly above (perpendicularly), e.g.on a ceiling above the surface 10, or at an angle to the surface 10, e.g. on a wall of a room, as long as its field of view covers the surface 10 to be monitored or the part thereof to be monitored. In the case of several optical sensors 20, it is advantageous to arrange them at different angles to the surface 10 of the object 1 in order to enable different viewing angles. This facilitates the scanning of the entire surface 10. In Figure 1, the optical sensor 20 covers the entire surface 10 of the object 1, as indicated by the lines pointing to the corners. The optical sensor 20 can be arranged close to the object 1, i.e. at a distance from it. The optical sensor 20 can be attached to a ceiling or a wall or a tripod or another suitable holder.

[0020] The optical sensor 20 preferably uses a scanning method and is designed, for example, as an ultrasonic sensor, a ToF sensor (ToF = Time-of-Flight, distance measurement using the time-of-flight method), or as a LIDAR sensor. Furthermore, more than one optical sensor 20 can be provided in order to cover a correspondingly large surface 10 or to provide a high resolution. The optical sensor 20 serves to detect several individual measuring points (indicated by the dashed arrows in Figure 1) on the surface 10, thereby generating a matrix of measuring points from which a two-dimensional profile 11 of the surface 10, i.e., a surface structure / a two-dimensional relief of the surface, can be created by a corresponding processing device. The number of measuring points and the distance between the measuring points, i.e., the resolution of the measurement, depend on the optical sensor 20 used and the application, i.e.,how precisely the profile must be recorded in order to be able to recognize objects 4 placed on it.

[0021] The monitoring device 2 further comprises a processing device in the form of, for example, a CPU, which serves to process the measurement points detected by the optical sensor 20, which may also include filtering, and to generate the two-dimensional height profile 11 of the surface 10 therefrom. It also serves to control the monitoring, i.e. when the optical sensor 20 is active and when it is not active. The optical sensor 20 is active when an activation request, e.g. a switch-on signal, is sent via a remote control 5 to the control and regulating device of the object 1, e.g. a sauna heater, and thus to the monitoring device 2. As soon as a switch-on signal has been received, the optical sensor 20 is activated and starts monitoring, i.e. scanning the surface 10. Before this can happen, however, at least one reference profile must be available as a comparison profile.For the sake of simplicity, only "one" reference profile will be mentioned below, although this does not preclude the use of multiple reference profiles. A reference profile is the profile 11 of the surface 10 that is present in a predetermined state of the object 1, e.g. a state after initial installation or a state defined as safe, and that is to be changed if an action is to be taken. It is therefore, for example, the profile that is determined to initialize the monitoring device 2. The reference profile can be detected by the optical sensor 20, or it can receive the reference profile as a finished data set for immediate use, or as an unfinished data set from which the processing device of the monitoring device 2 must still calculate the reference profile. In any case, the reference profile is stored in the processing device, advantageously persistently, e.g. in a non-volatile memory.

[0022] The reference profile can only be generated by activating the initialization directly on the monitoring device 2, e.g., by pressing a control element such as a button. This ensures that the surface 10 is in the state to be used as the reference value.

[0023] The current profile 11 of the surface 10 can either be detected by the optical sensor 20 by scanning the surface 20 at least once, and the current profile 11 of the surface 10 is calculated therefrom in the processing device and defined as a reference profile. Alternatively, if the surface structure (profile 11) of an object 10 is known, this can be made available to the monitoring device 2, or more precisely to its processing device, as a directly processable data set, e.g., via a corresponding wireless or wired interface. Further alternatively, information regarding the surface structure (of the profile 11) can be made available to the processing device, which it then processes in such a way that a reference profile is generated therefrom.Such information may be the signal propagation time between optical sensor 20 and surface 10, the reflection behavior of surface 10, the color of surface 10, the material of surface 10, the surface texture, the distance between optical sensor 20 and surface 10 per measuring point, the position of the optical sensor(s) 20 (in all spatial directions) or a combination thereof.

[0024] As soon as the reference profile is known, monitoring can begin. To do so, the optical sensor 20 scans the surface 10 at least once to determine the current profile 11 and thus the surface profile 11 to be compared with the reference profile. Advantageously, the optical sensor 20 scans the surface 10 multiple times to reduce measurement errors. Scanning can occur continuously or at intervals, i.e., with pauses between scans. The term scanning means that a measurement is taken once at each measuring point and the result is transmitted to the processing device for further processing. Surface monitoring continues until a shutdown condition is met or the monitoring device receives a shutdown signal. The duration of monitoring depends on the application.Shutdown conditions can be specified in a separate control and regulation device 3, which communicates with the monitoring device 2, or directly in the monitoring device 2 if the latter is part of the control and regulation device 3. Shutdown can also be initiated directly at the monitoring device 2, e.g., by a user, or remotely, i.e., with an external remote control 5, depending on the application. The control and regulation device 3 can be part of the external remote control 5, as indicated in Figure 1, or formed as a separate unit or part of the monitoring device 2.

[0025] Monitoring is performed by the processing device comparing the at least one stored reference profile with the measured profile 11 and evaluating whether the measured profile 11 exceeds or falls below a limit value of a permissible deviation (depending on the measuring principle). If this is the case, it can be assumed that an object 4 is located on the surface 10 of the object 1.

[0026] In a simple case, a sum of the measured distances of the individual measuring points from the surface 10 can be used as a reference profile. If this sum changes during the current measurement (the monitoring) and exceeds or falls below a predetermined limit value (depending on the measuring principle), then it can be assumed that an object 4 is located on the surface 10. The measurement can be refined as desired by the type and number of optical sensors 20 and a computational processing, for example, to detect a more precise position or shape and size of the object 4 or a color difference from the reference profile.

[0027] If it is detected that a predetermined limit has been exceeded or not reached, the processing device can output a signal. The output signal can be sent to an external device such as the remote control 5, which converts it and outputs it in the form of an alarm and / or a control signal. Of course, a signal can also be output directly to the monitoring device 2. The signal can be a switch-on signal for a warning light or a warning tone. Such an alarm signal can be an acoustic warning, e.g. in the form of a tone, a visual warning, e.g. by means of a two-color (green / red) light or a display in the form of text or image, or a haptic warning, e.g. in the form of vibrations of the remote control 5, with which the activation of the monitoring device 2 is triggered, or a combination thereof.Furthermore, the signal can be a control signal to prevent or abort activation of the object 1 having the surface 10. Such an object 1 can be, for example, a sauna heater or a machine for processing workpieces. The control signal revokes the authorization to activate the object 1, which is usually achieved by disconnecting it from the power supply.

[0028] In one embodiment, the signal is output with a time delay in order to enable and evaluate multiple scans (i.e., measurement series) of the optical sensor 20 in order to reduce incorrect measurements and thus incorrect outputs of the signal and to ignore temporarily occurring impairments of the measurement or evaluation.

[0029] In one embodiment, if an object 4 is detected on the surface 10, activation can only occur again when an unlocking unit provided in the area of ​​the monitoring device 2 and thus of the object 1 is activated, e.g., by pressing a button. This ensures that a person on site can verify that no object is (or is no longer) present on the surface 10.

[0030] In one embodiment, it can be provided that specified areas of the detected surface 10, i.e., the reference profile, are excluded (masked) from subsequent monitoring. For example, in the case of round furnaces, masking allows the obscuring of corners detected by the measurement that are not relevant. Masking could also be used to mask out non-critical areas, so that a detected object (deviation from the reference profile) no longer leads to a shutdown (withdrawal of approval) and / or an alarm.

[0031] The invention is described in more detail below using a preferred embodiment, in which a surface 10 of a sauna heater is monitored as object 1. The heater is used in a heated room, referred to as a sauna for short. The term "sauna" refers to all rooms that can be heated with a so-called sauna heater, i.e., both the classic Finnish sauna and saunas with lower or higher temperatures and lower or higher humidity, as well as steam baths, etc.

[0032] In saunas, it is prescribed that the sauna heater may only be switched on if a person has physically verified that, among other things, no object 4 is located on the surface 10 of the sauna heater. This is to prevent fires caused by objects 4 that are located on the heater and can ignite after it is switched on and heated up. Such objects 4 can be wooden buckets, towels, wooden spoons, cloths (including cleaning cloths), etc., which are not normally located on the sauna heater during operation, especially the very hot stones. The proposed monitoring device 2 can reliably detect, even remotely, whether a foreign object 4 is located on the surface 10 of the heater, i.e., whether the detected profile deviates from the reference profile. If this is the case, authorization to operate the heater can be withdrawn, i.e.,The oven can be automatically prevented from turning on, or it can be automatically turned off. This eliminates the need for a person to be physically near the oven to turn it on and monitor it.

[0033] As already described, at least one reference profile for the oven is determined in the monitoring device 2 during installation or in the event of a change to the oven, e.g. addition or removal of stones or fragrance vessels, etc. This is compared with a measured, current profile 11 when the oven is switched on remotely, and an assessment is made as to whether the difference between the profiles 11 exceeds or falls below a limit value. Thus, without a person being present, it can be detected whether an object 4 is on the surface 10 of the oven, and if an object 4 is detected, a signal can be sent from the monitoring device 2 to the control and regulation device of the oven so that this switches the oven off (or prevents it from being switched on). At the same time, a signal can also be sent to, for example,The remote control then processes the information as described above and serves to remotely switch on the furnace. Such a remote control can be a separate panel, but also a user's mobile phone with a corresponding software interface and a so-called app. The monitoring device 2 can be part of the furnace's control and regulation system or a separate unit that communicates with the furnace's control and regulation system.

[0034] This allows remote monitoring of one or more sauna heaters to be provided, which also makes it possible to remotely switch on the sauna heater(s).

[0035] The described monitoring device 2 can, however, not only be used to monitor surfaces 10 of sauna heaters, but also to monitor other surfaces 10 on which objects 4 (including people and animals) can be placed, i.e., any type of storage surface. For example, table surfaces for depositing packages or other objects 4 can be monitored, and a signal can be issued if it is detected that an object 4 is on the table. Work tables can also be monitored, and machines can be prevented from placing objects 4 on them if it is detected that an object 4 is already on the work table. Furthermore, damage to objects 4 such as toilets can be detected, e.g., if a toilet seat is no longer present, or if no object 4 (in the form of a person) has been detected on the toilet for an extended period of time.

[0036] The proposed monitoring device 2 can therefore initially create a reference profile for essentially any surface. During monitoring using the optical sensor 20, deviations of the measured surface profile from the reference profile can be detected, and appropriate measures can be taken, depending on the application.

[0037] The advantage of the proposed monitoring device 2 is that it is no longer necessary for a person to be physically present to check whether the surface 10 of the object 1 corresponds to the stored reference profile, i.e., whether it is usable or not damaged, depending on the application. Also, a camera is not required to monitor the surface 10, which is desirable in certain applications.

[0038] The proposed invention enables remote monitoring of surfaces. This simplifies processes such as turning on sauna heaters or reduces the need for personal checks. It is particularly advantageous that the monitoring device 2 can be remotely controlled, in particular switched on and off. A corresponding interface is naturally required for communication with a remote control 5 and / or a control and regulation device 3.

[0039] List of reference symbols

[0040] 1 object, e.g. sauna stove

[0041] 10 Surface of 1

[0042] 11 two-dimensional profile / relief of 10

[0043] 2 monitoring device

[0044] 20 optical sensor

[0045] 3 Control and regulation device

[0046] 4 Object

[0047] 5 Remote control

Claims

Patent claims 1 . Monitoring device (2) for optically monitoring surfaces (10) of an object (1) on which objects (4) can be placed, the monitoring device (2) comprising: - at least one optical sensor (20) which is or are designed to optically detect at least partial areas of the surface (10), and - a processing device which is in communication connection with the at least one optical sensor (20) and is designed to determine or store at least one reference profile of the surface (10) and to process measured values ​​recorded during monitoring in such a way that it detects a deviation of a currently measured profile (11) from the reference profile and, depending on the detected change, outputs a signal in order to communicate that an object is located on the surface and / or to prevent release of an operation of the object (1), in particular in the case of a remote-controlled activation request.

2. Monitoring device (2) according to claim 1, wherein the processing device is arranged to output the signal only after a predetermined time.

3. Monitoring device (2) according to one of the preceding claims, wherein the output signal is an acoustic signal and / or an optical signal and / or a haptic signal.

4. Monitoring device (2) according to one of the preceding claims, wherein the object (1) is a device which is operated by means of energy, and the output signal of the device withdraws a release for operating the device.

5. Monitoring device (2) according to one of the preceding claims, wherein the optical sensor (20) is configured to record the measured values ​​continuously or at intervals.

6. Monitoring device (2) according to one of the preceding claims, wherein, for initializing the monitoring device (2), the optical sensor (20) determines a profile of the surface (10) as a reference surface, or wherein a profile (11) of the surface (10) is stored as a reference surface in the processing device, or wherein the processing device processes predetermined information on the reference surface and determines a profile (11) of the surface (10) as a reference surface therefrom.

7. Monitoring device (2) according to one of the preceding claims, wherein the monitoring device (2) has an operating element, by the operation of which the detection of the reference surface takes place.

8. System comprising a sauna heater and a monitoring device (2) according to one of the preceding claims, wherein the monitoring device (2) is arranged and configured to monitor a surface of the sauna heater in such a way that, in the event that it receives a remote-controlled switch-on signal as an activation request and the processing device detects a deviation of a currently measured profile (11) from the reference profile and an exceeding of a predetermined limit value, it outputs a signal in such a way that switching on of the sauna heater is prevented.

9. Sauna, comprising the monitoring device (2) according to one of claims 1 to 7 or the system comprising sauna heater and monitoring device (2) according to claim 8.

10. Method for optically monitoring surfaces (10) of an object (1), on which objects (4) can be placed, by means of a monitoring device (2) according to one of the preceding claims, wherein in an initialization step a profile (11) of a reference surface is detected or specified and stored by the processing device, and then, upon a switch-on signal, the current surface (10) is at least partially scanned by means of the at least one optical sensor (20) in such a way that a current profile (11) of the surface (10) is determined, wherein in the event of detection of a change in the reference profile such that a limit value is exceeded, a signal is output to prevent operation of the object (1) and / or to communicate that an object (4) is located on the surface (10).

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