CN111188177B

CN111188177B - Laundry dryer with acceleration sensor and method for operating the same

Info

Publication number: CN111188177B
Application number: CN201911093348.9A
Authority: CN
Inventors: B·米尔克; A·施托尔策
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2018-11-13
Filing date: 2019-11-11
Publication date: 2023-08-25
Anticipated expiration: 2039-11-11
Also published as: EP3653782B1; DE102018219361A1; CN111188177A; EP3653782A1

Abstract

The present invention relates to a laundry dryer, which comprises: a control device; a drum for receiving laundry, at least one laundry mover being arranged in the drum, wherein a sensor assembly with at least two sensors, a self-sufficient energy supply unit and an interface for wireless communication are located in the laundry mover; and at least one evaluation unit for sensor signals of the sensor assembly, wherein the control device and the sensor assembly are provided for wireless communication with each other and an acceleration sensor, at least one electrode of the conductivity sensor and/or an air humidity sensor are arranged in the laundry carrier, and the control device is provided for determining the position of the laundry carrier when the drum rotates, so that the sensor signals detected by the conductivity sensor and/or the air humidity sensor can correspond to the position of the laundry carrier. The invention further relates to a method for operating the laundry dryer.

Description

Laundry dryer with acceleration sensor and method for operating the same

Technical Field

The invention relates to a laundry dryer with an acceleration sensor, by means of which better control can be achieved, and to a method for operating the laundry dryer. The present invention relates to a laundry dryer, comprising: a control device; a drum for receiving laundry, in which at least one laundry mover is arranged, wherein a sensor assembly with at least two sensors, a self-sufficient energy supply unit and an interface for wireless data communication are located in the laundry mover; and at least one evaluation unit for the sensor signals of the sensor assembly, wherein the control device and the sensor group are provided for wireless communication with each other.

Background

The development of laundry dryers aims to design more reliable and easier operation for the user, and to continuously improve the drying program implemented herein in terms of performance, time, energy consumption and environmental compatibility. For this purpose, it is essential to be able to determine the operational-related parameters at any time.

In general, for this purpose, a sensor, for example a sensor operating in resistive or capacitive mode, is incorporated in the laundry dryer, which sensor can determine, for example, the residual moisture in the laundry by means of a resistance measurement or can infer the course of the drying program by measuring the temperature and/or humidity of the process air used for drying, so that, for example, the end of the program can be displayed. It is also known to use pressure sensors or acceleration sensors, for example, to determine the load. The disadvantage is that the sensors are often arranged at different points in the laundry dryer, so that high inaccuracies in the measured sensor signals may result from the sensors detecting different measuring points. Furthermore, sensors often require a large installation space, so that the arrangement cannot be designed flexibly, and in many cases a greater distance between the actual measurement object and the sensor is produced, and the sensor signal is inaccurate. It is therefore desirable to be able to realize the sensor assembly with as little installation space as possible.

Publication DE 10 2012 217 975 A1 describes a household appliance having a control device for controlling an operating process of the household appliance and a battery-free electronic sensor unit for detecting at least one operating parameter of the household appliance, wherein the sensor unit has a generator for supplying the sensor unit with electrical energy from non-electrical energy and a transmitter which is designed for wirelessly transmitting a radio signal which characterizes the at least one operating parameter to the control device. The generator is a thermoelectric generator having two thermal contact surfaces, the thermoelectric generator being designed to provide electrical energy based on a temperature difference between the contact surfaces.

Publication EP 1 895 043 A1 describes a washing machine and/or laundry dryer, in particular for domestic use, which is provided with a rotating drum for receiving laundry to be washed and/or dried, and with a control device which is able to measure at least one functional parameter of the machine, for example the humidity of the laundry. The measuring device is connected to the control panel in order to operate the measuring device in accordance with the detected measured variable. The measuring device here comprises an electrical generator which is directly associated with the rotating drum and which communicates wirelessly with the control panel of the machine. The electric energy generator comprises a permanent magnet which slides freely in a tube made of non-conductive material, wherein at least one coil is wound on the outer surface of the tube, said coil being connected to a distribution board which is able to finely control the voltage signal and to send it to the control panel of the machine.

Publication EP 1 997 951 A1 describes a washing machine comprising a rotating drum with a front access opening. The washing machine further comprises an electronic device adapted to the drum and a generator, which is built into the drum and is used for rotating the drum, in order to generate the electrical energy required for operating the electronic device.

Publication DE 102,144 A1 and WO 2004/022836 A2 describe a laundry dryer with a rotating drum for receiving laundry to be dried, wherein the drum has a sensor device for determining a physical value inside the drum, which sensor device is connected by signal transmission to a control device of the laundry dryer, and the connection of the signal transmission is designed wirelessly and contactlessly.

Publication DE 10 2006 053 274 A1 describes a method for determining the load of laundry in a loading chamber with an outlet of a laundry dryer, in particular a ventilated laundry dryer, wherein the absolute air humidity in the outlet of the loading chamber is measured, wherein the load in the loading chamber is determined by determining the maximum value and/or the profile of the absolute air humidity in the exhaust air of the loading chamber.

Publication WO 2013/182402 describes a washing machine or dryer comprising a drum into which laundry may be put, one or more deflectors (baffles) mounted on the inner surface of the drum, one or more sensors arranged in the drum, and a main conditioning unit controlling the washing or drying operation. In this case, an additional regulating unit is arranged in the deflection element, which converts the analog signal obtained by the sensor into a digital signal and transmits the signal to the main regulating unit. The temperature sensor directed towards the inside of the drum may be arranged on the surface of the deflector. The additional regulating unit may perform wireless transmission of the signal.

Publication WO 2018/015214 describes a household appliance having a control device and at least one sensor node, which comprises at least one sensor, at least one evaluation unit, a self-sufficient energy supply device and an interface for wireless data communication, wherein the control device and the sensor node are provided for wireless communication with each other, wherein the at least one sensor is a micromechanical sensor, and the at least one sensor node is provided such that it can be controlled not only by the control device, but also independently detect and evaluate at least one measurement signal and transmit the at least one measurement signal to the control device.

Disclosure of Invention

Against this background, the object of the present invention is to provide a laundry dryer with an improved control device. An improved monitoring and control of the drying program should preferably be achieved, for which purpose in particular also the humidity of the laundry and/or the load of the laundry in the drum should be able to be determined. A method suitable for operating the laundry dryer should furthermore be provided.

According to the invention, this object is achieved by a laundry dryer and a method for operating the laundry dryer, which have the features of the respective preferred embodiments. In the corresponding alternative, preferred embodiments of the laundry dryer according to the invention and of the method according to the invention are listed. The preferred embodiments of the laundry dryer according to the invention correspond to the preferred embodiments of the method according to the invention, and vice versa, even if not explicitly stated herein.

Accordingly, the subject matter of the present invention relates to a laundry dryer having: a control device; a drum for receiving laundry, in which at least one laundry mover is arranged, wherein a sensor assembly with at least two sensors, a self-sufficient energy supply unit and an interface for wireless communication are located in the laundry mover; and at least one evaluation unit for sensor signals of the sensor assembly, wherein the control device and the sensor assembly are provided for wireless communication with each other and at least one electrode of an acceleration sensor, a conductivity sensor and/or an air humidity sensor are arranged in the laundry carrier, and the control device is provided for determining the position of the laundry carrier when the drum rotates, so that the sensor signals detected by the conductivity sensor and/or the air humidity sensor can correspond to the position of the laundry carrier.

The laundry dryer may be the dryer itself or a washing dryer, i.e. an appliance combining the functions of a washing machine and a dryer.

As acceleration sensor, a capacitive sensor may be used, for example. Resistive load bar based sensors may also be used. Furthermore, not only a single axis sensor but also a sensor having two or more measuring axes may be used.

In a preferred embodiment of the laundry dryer according to the present invention, the acceleration sensor is a sensor having three measuring axes; in particular a micromechanical acceleration sensor with three measuring axes. In this way, it is also possible to detect wear phenomena or unbalance in the laundry dryer according to the invention with dynamic components, i.e. for example in the drum, by evaluating the individual measuring-axis signals and their frequency components.

The load of the drum and the slip of the drum relative to the drive motor and the unbalance of the drum can also be advantageously calculated using the acceleration sensor and, if necessary, compensated for by the control device. Furthermore, the position and speed of the drum can be identified by measuring the axis signal with z. Furthermore, aging effects, such as wear of the roller bearings or aging of the drive train, can also be detected by the acceleration signal, and if necessary information can be output to the user via the control device.

In particular, the loading degree of the laundry in the drum can be accurately measured. The laundry collides with the laundry carrier due to the rotation of the drum and acceleration pulses are generated in this manner, which are detected by the acceleration sensor. The degree of loading can be determined by the type and magnitude of the sensor signal. The measurement accuracy is improved here with respect to a plurality of different rotational speeds.

In a further preferred embodiment of the laundry dryer, at least two electrodes are used as conductivity sensors, which are arranged on at least one laundry mover, so that the conductivity between the at least two electrodes can be measured. The two electrodes can also be arranged on different laundry carriers. If the measured conductivity between the two electrodes is relatively low, it can be inferred that there is no wet washings between the electrodes. Depending on the arrangement and number of the electrodes, the load of the wet laundry on the drum can be deduced from the corresponding sensor signals.

In a preferred embodiment of the laundry dryer, the counter electrodes of the conductivity sensors are arranged on the same laundry carrier or on different laundry carriers.

In an alternative embodiment of the laundry dryer, the drum housing of the drum is used as counter electrode for the conductivity sensor.

According to the invention, a laundry dryer is particularly preferred, wherein the control device is provided for determining the laundry humidity and/or the load of laundry in the drum as a function of the sensor signals detected by the conductivity sensor and/or the air humidity sensor. That is, different filling of the drum is obtained according to the laundry amount, i.e., the load of laundry in the drum and the laundry humidity. This affects the washing situation when the drum rotates, wherein the rotational speed of the drum additionally affects the washing situation. At a constant rotational speed of the drum, the washing condition is related to the laundry amount and the laundry humidity. Therefore, the drum case region and the laundry mover are contacted with the laundry differently in frequency as the drum rotates. In order to detect at which point in the laundry drive a sensor signal, for example an air humidity sensor or a conductivity sensor, is detected during the movement of the drum, the sensor signal of the acceleration sensor is evaluated, so that the sensor signal detected by the conductivity sensor and/or the air humidity sensor corresponds to the position of the laundry drive.

For this purpose, one of the measuring axes of the acceleration sensor is usually arranged parallel to the rotational axis of the drum, so that the angular position of the drum and thus the position of the associated laundry drive can be deduced from the value of the acceleration in two further directions. It is thereby possible to make the measured value of the air humidity and/or the electrical conductance correspond to the position of the drum. From the intensity of the sensor signal at this location, the load of the laundry and the laundry humidity of the laundry can be deduced. In this case, the time period of the measured sensor signal can also be taken into account, in particular at a known rotational speed of the drum. Finally, with a smaller load of laundry, less contact of the laundry carrier with the laundry is brought about. In the case of smaller loads, fewer laundry carriers come into contact with the laundry as the drum rotates than in the case of larger loads. In addition, it is conceivable that the contact surface of the laundry with the laundry carrier becomes smaller as the degree of drying of the laundry increases.

In accordance with the invention, the corresponding relationship is preferably stored in the control unit of the laundry dryer, for example, also taking into account the rotational speed of the drum, in order to evaluate it as accurately as possible.

In a preferred embodiment of the laundry dryer, at least two sensors of the sensor assembly are based on the same measuring principle and are arranged along the laundry mover. The accuracy with which it is possible to determine the laundry humidity and the laundry load by means of the invention can thereby be further improved.

The wash-ware drivers are generally arranged substantially parallel to the axis of rotation of the drum, so that the concept "along the wash-ware drivers" is explained below, which arrangement is realized substantially parallel to the axis of rotation of the drum. In this arrangement, the sensors have a distance from one another at least in the direction of the laundry drive, wherein the distance is generally determined in each case from the projection of the position of the sensor onto an imaginary axis which extends parallel to the axis of rotation of the drum. Thus, the three sensors along the laundry carrier determine two distances, namely a first distance d between the first sensor and the second sensor ₁ And a second spacing d between the second sensor and the third sensor ₂ . Distance d ₁ And d ₂ May be the same or different. This applies correspondingly to other spacings d in the case of four or more sensors _n (n>2)。

In a preferred embodiment of the laundry dryer, the measuring principle is selected from the group consisting of physical properties, i.e. temperature, humidity, pressure and/or conductivity, whereby the at least two sensors are temperature sensors, air humidity sensors, pressure sensors, conductivity sensors, respectively, or any combination thereof. For example, there may be a pair of temperature sensors and a pair of air humidity sensors.

In a preferred embodiment of the laundry dryer according to the invention, the temperature sensor optionally used is a micromechanical temperature sensor, which consists of an n-type silicon crystal produced in planar technology.

Furthermore, it is particularly preferred according to the invention to use as sensor a multiple sensor which is based on a plurality of measurement principles at the same time. Such space-saving dual or triple sensors are known.

The at least two sensors of the laundry dryer preferably have a measuring range of 2-4 x 0.5-1.5mm, respectively ³ Modular components of a size in the range.

The sensor is usually designed as a micromechanical sensor. Since micromechanical sensors are particularly small components, i.e. require little installation space, two or more sensors can be assembled, thus forming, for example, a dual sensor or a triple sensor. For this purpose, the sensor can be constructed in particular modularly. However, the compact design of the micromechanical sensor offers a further decisive advantage. That is, if micromechanical sensors are used, all sensors can be measured at the same location. The sensor signals all have a common position reference point. The parameters obtained from the individual sensor signals can thus be correlated with one another particularly accurately.

In any case, a sensor device comprising at least one micromechanical sensor, an interface for wireless data communication and a self-sufficient energy supply unit, and if necessary an evaluation unit, can be realized in a particularly small installation space.

In a further preferred embodiment of the laundry dryer according to the invention, the at least one sensor of the sensor assembly arranged in the laundry mover, for example the micromechanical sensor, is a pressure sensor with a diaphragm. The pressure exerted by the laundry on the membrane when in contact with the laundry carrier can then advantageously be transmitted to the pressure element in the pressure sensor. This may additionally improve the determination of the load of laundry in the drum. The laundry collides with the laundry carrier due to the rotation of the drum and in this way generates a pressure acting on the laundry carrier, which pressure can be detected by the pressure sensor. The loading level can then be determined from the type and the magnitude of the measurement signal.

If the at least one sensor is a pressure sensor, in particular a micromechanical pressure sensor, the at least one sensor assembly transmits the evaluated sensor signal to the control device and initiates switching on the tumble dryer if the pressure sensor detects a sensor signal after placing the laundry in the tumble dryer when the latter is switched off.

The invention can in the described embodiment monitor the drying program by evaluating the sensor signals of the sensors arranged in the direction of the laundry carrier or in the direction of the rotation axis of the drum. In general, when a drying program for wet laundry is carried out, the process air flowing in a so-called process air duct flows into the drum from behind after it has been heated by the usual heating devices of laundry dryers. As it passes through the drum to the front side, the process air, which is otherwise very hot and dry, gradually cools and at the same time absorbs moisture from the laundry to be dried. In addition, the washings are pushed generally forward in the direction of the access door as a result of the flow of process air. In this case, the laundry closest to the incoming process air is usually dried most strongly. Overall, therefore, gradients in the temperature and humidity of the process air are produced in the drum in the direction of its axis of rotation. Determining the position-dependent temperature and humidity of the air in the drum as precisely as possible is of great importance for an improved control of the drying process. The laundry humidity and the load of laundry in the drum can thus be better determined. Thus, the non-uniformity in drying can be compensated for, for example, by appropriately varying the blower power, the heating power, and the drum rotation. The desired end of drying can also be determined more accurately.

In a particularly preferred embodiment of the invention, at least three sensors, preferably at least four and particularly preferably at least six sensors are thereby arranged along at least one laundry mover. In general, these sensors are based on the same measuring principle, in order to be able to monitor changes in properties, such as the air humidity, in the direction of the rotation axis or the laundry drive as accurately as possible.

In addition to the acceleration sensor, the sensor discussed here is arranged on the surface of at least one laundry carrier. However, it may be provided that one or more sensors are also arranged inside the laundry carrier, for example as temperature sensors for monitoring the normal functioning of the electronic components.

In addition to the sensors arranged in the drum in the laundry drive, further sensors can optionally be arranged for replenishment in the process air duct, for example at the drum inlet and/or at the drum outlet. The sensor can be based on different measuring principles, for example temperature, humidity, pressure, wherein dual sensors and triple sensors can also be used. The sensor arranged outside the drum may additionally help to better monitor the drying program.

Furthermore, a laundry dryer is preferred, wherein the control device is provided for determining the load of the laundry in the drum and/or the degree of drying of the laundry as a function of the sensor signal detected by the sensor and/or the position gradient of the sensor signal in the direction of the laundry mover. In other words, in the case of a sensor arranged along the laundry carrier, it can be determined, when the drum rotates, how far from the inlet opening of the drum the sensor signal changes, which can be attributed to the fact that no laundry is arranged here anymore.

The background for this is that different fills of the drum can be produced depending on the amount of laundry in the drum, i.e. the load of the drum and the humidity of the laundry. The washings are pressed towards the dryer door when process air is preferably entered at the rear wall of the drum. Only the front area of the drum may be filled in the case where the drum enters according to the amount of laundry in the drum. In addition, the laundry is dried faster at the drum inlet than at the drum outlet in this preferred flow direction of the process air. The invention can be realized in the described embodiment by identifying the filling level in relation to the load and the humidity of the laundry, i.e. the drying level of the laundry, as a function of the drum depth, i.e. as a function of the position along the laundry mover. The drying state and the load of the laundry can thus be more accurately determined and the drying process can thus be more accurately arranged.

In a particularly preferred embodiment of the laundry dryer, the control device is provided for taking into account the intensity of the air flow entering the drum in order to determine the load of laundry in the drum and/or the degree of drying of the laundry. Here, the strength of the air flow includes not only the amount of process air but also the flow rate. The intensity of the air flow can be adjusted by the power of the blower in the drying passage of the laundry dryer.

According to the invention, the laundry dryer preferably has at least two laundry drives, in which a sensor assembly with at least two sensors, a self-sufficient energy supply unit and an interface for wireless data communication are located. In this case, the control device of the laundry dryer is preferably provided for determining the load of the laundry in the drum, taking into account the rotational speed of the drum, as a function of the sensor signals detected by the sensor assemblies in the at least two laundry drives and/or of the position gradients of the sensor signals in the direction of the laundry drives. If at least two laundry carriers each have an acceleration sensor, then the local position of the acceleration sensors can also be taken into account during the rotation of the drum.

Furthermore, a laundry dryer is preferred, wherein at least one sensor arrangement is provided for being controlled by the control device and/or for being able to independently measure, evaluate and transmit at least one sensor signal to the control device.

In the laundry dryer according to the present invention, preferably, the wireless communication between the control device and the at least one sensor assembly can be implemented in two directions. In other words, in one embodiment, for example, the sensor signal sets that are individually detected by the sensor assembly and then evaluated can be transmitted to the control device. Furthermore, the control device can preferably also transmit signals to the sensor assembly, for example for querying the sensor signals. The control device is preferably configured to perform an action in the laundry dryer as a function of the sensor signal transmitted by the at least one sensor assembly or an evaluation of the sensor signal.

"action" in the sense of the present invention means any possibility of controlling the laundry dryer according to the present invention. That is, the action may, for example, perform a drying program or also perform a part of the drying program. The drying program in the sense of the invention can be a factory-set drying program in a laundry dryer, one or more additional options or also a user-defined drying program. Accordingly, the term drying process is to be construed broadly in accordance with the present invention. In the sense of the invention, the action can also be simply switching on or off the laundry dryer, switching on or off a heating device or a process air blower of the laundry dryer or changing their power, displaying an output on an operating element of the laundry dryer or also a sound signal for outputting information to the user.

In any event, the term "action" includes any possible manner of control of the laundry dryer according to the present invention.

In the laundry dryer according to the present invention, the control device and the at least one sensor assembly are provided for wireless data communication. In this case, the at least one sensor assembly and the control device and/or the evaluation unit are preferably provided for wireless communication with one another via a bluetooth low energy connection. The connection can be realized in all possible ways, for example via individual radio interfaces or also via interfaces in the evaluation unit and the control device.

In the laundry dryer according to the invention, at least one laundry mover comprises a self-sufficient energy supply unit. According to the invention, the term "self-sufficient energy supply unit" as used herein means that the energy supply unit is provided for generating energy independently, i.e. independently of the energy supply means of the laundry dryer.

When the laundry dryer is switched off, the sensor device is also able to independently detect and evaluate the sensor signal in the manner described and to transmit the sensor signal to the control device. The manner of energy supply is not limited here. However, the energy supply can also be effected, for example, thermally, inductively or piezoelectrically. Any method known from the prior art is possible in principle here. In addition to this, batteries or accumulators are also conceivable for the power supply.

If the energy supply unit comprises thermopile elements, at least one thermopile element may be arranged in or on the wash load carrier. A temperature difference can then occur at both ends of the thermopile element during contact with hot laundry or also as a result of hot process air. The voltage difference generated can then be measured at one end.

If the energy supply unit comprises magnetic induction elements, i.e. for example coils and magnets, the coils can be arranged in the laundry carrier and the magnets can be fastened to the housing of the laundry dryer, so that the coils can be guided past the magnets at a defined distance by the drum movement. The induced current thus generated can then be measured. Magnetic flux collectors may additionally be used to increase efficiency in order to direct the magnetic field further onto the coil through openings in the drum.

In an alternative embodiment, the magnet can also be arranged in the laundry carrier, in particular can be moved such that it can pass by adjacent coils when the drum is moved up and down. In this way, the energy supply unit can also advantageously be fully integrated into the laundry carrier.

In a preferred embodiment of the invention, the self-sufficient energy supply unit comprises at least one piezoelectric element for generating energy and is provided for generating energy for the sensor assembly, the interface for wireless data communication and/or the evaluation unit by mechanical deformation of the at least one piezoelectric element.

The invention thus advantageously makes use of the so-called piezoelectric effect in which electrical energy is generated by mechanical deformation.

In a preferred embodiment of the household appliance according to the invention, the at least one piezoelectric element is optionally a piezoceramic bending element.

The shape of the bending element is not limited in this context, and the bending element may have any geometric shape. However, the bending element is preferably constructed flat, particularly preferably in a rectangular shape. The size and offset of the bending elements is not limited in accordance with the present invention. This is generally related to the position of the piezoelectric element and the mechanical stress applied to the piezoelectric element.

In any case, the piezoceramic bender generally comprises a bender structure and electrodes. The curved structure can be realized in different ways, for example as a layered structure. The bending structure may also be a combination of one or two piezoceramic components, which may also have at least one intermediate layer. The piezoceramic element can also be composed of a single layer and/or of a plurality of layers, the layer thicknesses of which are likewise not limited.

The piezo-ceramic material is not limited according to the invention, and may be, for example, lead zirconate titanate, although any other piezo-ceramic may be used.

In a preferred embodiment of the laundry dryer according to the invention, the piezo ceramic bending element optionally used has a piezo ceramic layer having a layer thickness of 100 to 500 μm in any case. The layer thickness is preferably in the range of 150 to 250 μm, for example 200 μm.

Preferably, the layers are then designed as plates and have surface electrodes on the upper and lower sides, respectively, and contact points and two electrical connections, respectively.

In a preferred embodiment of the laundry dryer according to the invention, the at least one optional piezo element is arranged in or on the laundry mover in such a way that it can be deformed by the laundry impinging on the at least one laundry mover during rotation of the drum. Preferably, the energy supply unit is fully integrated into the laundry drive, so that the sensor assembly can be produced together with the energy supply unit as a compact modular assembly.

In general, laundry dryers also have at least one display unit which is capable of displaying information in the form of text, images and/or symbols, in color and/or black and white, statically and/or dynamically. Preferably, the information and/or warning may be output to the user through the display unit. Very particularly preferably, the display unit is an external display unit, such as a touch screen of a smart phone or tablet.

The laundry dryer includes an evaluation unit for evaluating the sensor signal. The evaluation unit can be arranged in the laundry drive or elsewhere in the laundry dryer. The type and configuration of the evaluation unit are not limited. The evaluation unit may for example be part of, i.e. be arranged in, at least one sensor. However, the evaluation unit may also be a separate processor unit. In any case, the evaluation unit is provided here for evaluating the sensor signals and transmitting them to the control device.

In a preferred embodiment of the laundry dryer according to the invention, the evaluation routine is also stored in the evaluation unit, and the evaluation unit is provided for not only calculating but also evaluating and, if preset according to the evaluation, transmitting to the control device a calibration value/calibration curve according to, for example, a setpoint/actual value comparison and/or according to a sensor signal measured by the sensor assembly. That is, if the actual value exceeds or falls below the stored nominal value.

In particular for households with networked appliances, the laundry dryer according to the invention preferably has an additional interface for wireless data transmission, wherein the laundry dryer can then preferably be operated by means of an external operating unit, for example a smart phone and/or a tablet computer, preferably by means of an App. Particularly preferably, the laundry dryer according to the invention is then also integrated into the home network together with at least one further household appliance.

In a preferred embodiment of the household appliance according to the invention, the laundry carrier additionally has an energy store. The energy storage device is not limited according to the invention and can be realized in any technically possible way, i.e. for example as a battery. Furthermore, the energy store can be provided, for example, in the piezoelectric element or can also be configured separately. In any case, the accumulator is used to store energy generated by the energy supply unit and supply the sensor assembly and the evaluation unit or the like with electric energy when necessary.

The invention also relates to a method for operating a laundry dryer, comprising; a control device; a drum for receiving laundry, in which at least one laundry mover is arranged, wherein a sensor assembly with at least two sensors, a self-sufficient energy supply unit and an interface for wireless communication are located in the laundry mover; and at least one evaluation unit for sensor signals of the sensor assembly, wherein the control device and the sensor assembly are provided for wireless communication with each other and an acceleration sensor, at least one electrode of the conductivity sensor and/or an air humidity sensor are arranged in the at least one laundry carrier, and the control device is provided for determining the position of the laundry carrier when the drum rotates, such that the sensor signals detected by the conductivity sensor and/or the air humidity sensor can be made to correspond to the position of the laundry carrier, wherein the method comprises the following steps:

(a) Rotating the drum;

(b) Detecting sensor signals of at least one electrode of the acceleration sensor and the conductivity sensor and/or the air humidity sensor; and

(d) The sensor signals of the sensors of the sensor assembly used in step (b) are evaluated by an evaluation unit in terms of the load of the laundry in the drum and/or the degree of drying of the laundry, wherein the sensor signals detected by the conductivity sensor and/or the air humidity sensor are assigned to the position of the laundry carrier, and the evaluation result obtained in this way is transmitted to the control device.

The control device can then further process the obtained evaluation results in a suitable form and/or display them on a commonly present display unit for the user of the laundry dryer. The drying program may be modified, for example, to more efficiently and/or uniformly dry. Alternatively or additionally, the end of drying can also be displayed in more detail on the display unit of the laundry dryer.

In the process air duct of a laundry dryer, a blower for conveying process air is usually present. Thus, in a preferred embodiment of the method according to the invention, a blower is arranged in the process air duct of the laundry dryer, and the following step (c) is carried out before step (d):

(c) The intensity of the air flow entering the drum is measured and taken into account in the evaluation in the following step (d).

In the method according to the invention, step (b) may preferably be initiated not only by the control means, but also by the sensor means independently of the control means. The control device may thus transmit a signal to the at least one sensor assembly, for example, in order to detect the sensor signal, and thus initiate step (b) of the method according to the invention. However, it is also possible to store routines, for example in the evaluation unit, in order to initiate the measurement independently and thus to start step (b) of the method according to the invention.

The present invention has a number of advantages. By means of the position-dependent measurement of various physical properties in the drum of the laundry dryer, it is possible to optimize the drying program better as a function of the position of the laundry mover in the rotation of the drum or, in the embodiment of the invention, additionally in the direction of the laundry mover, in such a way that the degree of drying of the laundry and the load of the laundry can be deduced precisely. Furthermore, the information can be transmitted out of the drum in a convenient manner, i.e. wirelessly. In an embodiment of the invention, the sensor assembly can be designed particularly flexibly and in a space-saving manner by using micromechanical sensors. In this case, a plurality of different sensor types can be provided in a variable number in the sensor assembly. Furthermore, it is particularly advantageous if, due to the compact design of the micromechanical sensor, all measuring signals can be detected in a position-dependent manner at the same measuring point. This makes it possible to achieve a particularly precise correlation of all values. Furthermore, by means of a self-sufficient energy supply unit, no electrical or mechanical contact between the control unit and the sensor assembly is required. Furthermore, the use of a low power wireless interface in embodiments ensures a long service life in optional battery operation due to low power consumption.

Drawings

Further details of the invention are derived from the following description of non-limiting embodiments. Reference is made herein to fig. 1 and 2.

Fig. 1 shows a vertical sectional view of a laundry dryer according to the present invention, which is configured as a condensation dryer.

Fig. 2 shows a partial view of the drum, wherein the laundry mover with the sensor system arranged therein is shown enlarged.

Detailed Description

Fig. 1 shows a vertical section of a laundry dryer according to the invention, which is configured as a condensation dryer, wherein the arrows indicate the flow direction of the process air. Other embodiments are contemplated.

The laundry dryer 1 shown in fig. 1 has a drum 3 rotatable about a horizontal axis for receiving laundry to be dried, not shown here, and a drive 5, 22 for moving the laundry during rotation of the drum is mounted inside the drum. Process air is guided in the process air duct 2 through the drum 3 by means of the process air blower 6 via the air-air heat exchanger 14 and the electric heater 4. The air heated by the electric heater 4 is guided into the drum 3 from behind, i.e. from the side of the drum 3 opposite the door 12, through the perforated bottom of the drum through the drum inlet 19.

After being discharged from the drum 3, the process air loaded with moisture flows through the filling opening of the drum 3 through the lint filter inside the door 12 closing the filling opening. The process air flow then passes down in the door 12 through the drum outlet 18 into the process air duct 2 and is led to the air-air heat exchanger 14, through which the cooling air in the cooling air duct 15 can be conveyed by means of the cooling air blower 16. The cooling in the air-air heat exchanger 14 causes a greater or lesser part of the moisture absorbed by the process air from the laundry to condense and be collected in the condensate basin 17.

The control of the dryer 1 is effected by means of a control device 8 which can be adjusted by a user via an operating unit 7.

In the two laundry drives 5, 22 of the laundry dryer 1 shown here, there are in each case a sensor arrangement 23, which is in the form of a triple sensor, with four sensors 24, 25, 26, 27, and an acceleration sensor 31, a self-sufficient energy supply unit 28, an interface 29 for wireless communication and an evaluation unit 30 for sensor signals of the sensor device 23, wherein the control device 8 and the sensor device 23 are provided for wireless communication with one another. The communication can take place here via the evaluation unit 30 connected in between. The sensor assembly triple sensors 24, 25, 26, 27 are based on the same measuring principle (temperature, pressure, humidity) and are arranged along the laundry drive 5, 22.

However, the sensors 24 and 25 can also be designed as conductivity sensors, wherein the electrodes 24 and the counter electrode 25 can be used. The electrode 24 and the counter electrode 25 may be arranged on the same wash-ware carrier or on different wash-ware carriers.

According to the invention, it can be determined, using the acceleration sensor 31, from the measured sensor signal, whether the laundry carrier in the defined angular position is still in contact with the laundry or in the vicinity of the laundry.

In the embodiment shown here two further sensors are arranged at the drum inlet and the drum outlet in order to provide further sensor signals for a more accurate design of the drying program. For this purpose, the two triple sensors 9, 10, namely the triple sensor 9 at the drum outlet 18 and the triple sensor 10 at the drum inlet 19, are connected to the control device 8. The triple sensors can measure the relative air humidity, temperature and air pressure of the process air, respectively, and thus provide important additional sensor signals, so that the remaining humidity of the laundry and in particular also the load of the laundry in the drum 3 can be better determined. For this purpose, a timer 20 is also present in the condensation dryer.

In the embodiment shown in fig. 1, the process air blower 6 and the drum 3 are driven by a drive motor 13. The drive motor 13 is in the embodiment described a brushless direct current motor (BLDC).

The display unit 21 can display a drying program, for example, a remaining running time for ironing, or a measured load or other state of the laundry dryer, or a status of the drying program, for example, in the form of color distinction, with respect to the laundry residual moisture value selected by the user.

In particular, a partial illustration of a section of a drum of the laundry dryer 1 of fig. 1 shows a laundry drive 5, 22 arranged on the drum with a sensor assembly having a self-sufficient energy supply unit 28. In the sectional view, only the acceleration sensor 31 and the triple sensor 24 (pressure, temperature, humidity) are visible from the sensor assembly. Furthermore, an evaluation unit 30 and a bluetooth low energy interface 29 for wireless data transmission are present in the laundry drive 9, 22.

List of reference numerals

1. Drying machine

2. Process air duct

3. Roller

4 (electric) heater

5. First driving piece

6. Process air blower, blower

7. Operation unit

8. Control device

9. Sensor for measuring temperature, relative humidity and/or air pressure at drum outlet

10. Sensor for measuring temperature, relative humidity and/or air pressure at drum inlet

11. Fluff filter screen

12. Door, access door to drum

13. A drive motor with variable rotation speed; in particular BLDC motor

14. A heat exchanger; in particular air-air heat exchanger

15. Cooling air duct

16. Cooling air blower

17. Condensed water basin

18. Roller outlet

19. Roller inlet

20. Timing device and clock

21 (optical) display unit

22. Second washings driving piece

23. Sensor assembly

24. A first sensor; single, double or triple sensor

25. A second sensor; single, double or triple sensor

26. A third sensor; single, double or triple sensor

27. A fourth sensor; single, double or triple sensor

28. Self-sufficient energy supply unit

29. Interface for wireless data transfer, bluetooth low energy interface

30. Evaluation unit

31. An acceleration sensor.

Claims

1. A laundry dryer (1) having: a control device (8); a drum (3) for receiving laundry, in which drum at least one laundry mover (5, 22) is arranged, wherein a sensor assembly with at least two sensors (24, 25, 26, 27), a self-sufficient energy supply unit (28) and an interface (29) for wireless communication are located in the laundry mover (5, 22); and at least one evaluation unit (30) for sensor signals of the sensor assembly (23), wherein a control device (8) and the sensor assembly (23) are provided for wireless communication with each other, characterized in that at least one electrode of an acceleration sensor (31) and a conductivity sensor (24, 25) and/or an air humidity sensor (26) is arranged in the laundry carrier (5, 22), and the control device (8) is provided for determining the position of the laundry carrier (5, 22) when the drum (3) is rotating, such that the laundry load and/or the degree of drying of the laundry in the drum (3) can be determined from the positional gradient of the sensor signals measured by the conductivity sensor (24, 25) and/or the air humidity sensor (26) in a direction substantially parallel to the axis of rotation of the drum (3).

2. Laundry dryer (1) according to claim 1, characterized in that the acceleration sensor (31) is a micromechanical acceleration sensor (31) with three measuring axes.

3. Laundry dryer (1) according to claim 1 or 2, characterized in that the counter electrodes of the conductivity sensors (24, 25) are arranged on the same laundry carrier (5) or on different laundry carriers (22).

4. Laundry dryer (1) according to claim 1 or 2, characterized in that the drum housing of the drum (3) is used as counter electrode of the conductivity sensor (24, 25).

5. Laundry dryer (1) according to claim 1 or 2, characterized in that at least two sensors (24, 25, 26, 27) of the sensor assembly (23) are arranged along the laundry mover (5, 22) based on the same measuring principle.

6. Laundry dryer (1) according to claim 5, characterized in that the measuring principle is selected from the group consisting of physical properties, i.e. temperature, air humidity, pressure and/or conductivity, whereby the at least two sensors are respectively a temperature sensor, a humidity sensor, a pressure sensor, a conductivity sensor or any combination thereof.

7. Laundry dryer (1) according to claim 1 or 2, characterized in that at least three sensors (24, 25, 26, 27) are arranged along the at least one laundry mover (5, 22).

8. Laundry dryer (1) according to claim 1 or 2, characterized in that as sensor a multiple sensor is used, which is based on a plurality of measurement principles simultaneously.

9. Laundry dryer (1) according to claim 1, characterized in that the control device (8) is arranged to take into account the intensity of the air flow into the drum (3) in order to determine the load of laundry in the drum (3) and/or the degree of drying of the laundry.

10. Laundry dryer (1) according to one of claims 1, 2, 6, 9, characterized in that it has at least two laundry drives (5, 22), in which a sensor assembly (23) with at least two sensors (24, 25, 26, 27), a self-sufficient energy supply unit (28) and an interface (29) for wireless data communication are located.

11. Laundry dryer (1) according to any one of claims 1, 2, 6, 9, characterized in that the at least one sensor assembly (23) and the control device (8) and/or the evaluation unit (30) are arranged for wireless communication with each other via a bluetooth low energy connection.

12. A method for operating a laundry dryer (1), the laundry dryer (1) having: a control device (8); a drum (3) for receiving laundry, in which drum at least one laundry mover (5, 22) is arranged, wherein a sensor assembly with at least two sensors (24, 25, 26, 27), a self-sufficient energy supply unit (28) and an interface (29) for wireless communication are located in the laundry mover (5, 22); and at least one evaluation unit (30) for sensor signals of the sensor assembly (23), wherein the control device (8) and the sensor assembly (23) are provided for wireless communication with each other and an acceleration sensor (31), at least one electrode of a conductivity sensor (24, 25) and/or an air humidity sensor (26) are arranged in the at least one laundry carrier (5, 22), and the control device (8) is provided for determining the position of the laundry carrier (5, 22) when the drum (3) is rotating, such that the laundry load and/or the degree of drying of the laundry in the drum (3) can be determined from the positional gradient of the sensor signals measured by the conductivity sensor (24, 25) and/or the air humidity sensor (26) in a direction substantially parallel to the rotational axis of the drum (3), wherein the method comprises the following steps: (a) rotating the drum (3); (b) -detecting sensor signals of at least one electrode of the acceleration sensor (31) and the conductivity sensor (24, 25) and/or the air humidity sensor (26); and (d) evaluating, by means of the evaluation unit (30), sensor signals of the sensors (24, 25, 26, 27, 31) of the sensor assembly (23) used in step (b) with respect to the laundry load and/or the degree of drying of the laundry, wherein the sensor signals measured by the conductivity sensors (24, 25) and/or the air humidity sensor (26) are made to correspond to the position of the laundry mover (5, 22), and the evaluation result obtained here is transmitted to the control device (8).

13. Method according to claim 12, characterized in that a blower (6) is arranged in the process air duct (2) of the laundry dryer (1) and that step (c) is carried out before step (d), which measures the intensity of the air flow into the drum (3) and takes into account the measured intensity of the air flow in the following step (d).