CN111188177A

CN111188177A - Laundry dryer with acceleration sensor and operation method thereof

Info

Publication number: CN111188177A
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: 2020-05-22
Anticipated expiration: 2039-11-11
Also published as: CN111188177B; DE102018219361A1; EP3653782A1; EP3653782B1

Abstract

The invention relates to a laundry dryer comprising: a control device; a drum for receiving laundry, in which at least one laundry carrier is arranged, wherein a sensor assembly with at least two sensors, a self-sufficient The energy supply unit and the interface for wireless communication are located in the laundry conveyor; 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 in the laundry conveyor An acceleration sensor, at least one electrode of an electrical conductivity sensor and/or an air humidity sensor are arranged in the element, and the control device is arranged to determine the position of the laundry carrying element when the drum rotates, so that the electrical conductivity sensor and/or the air humidity The sensor signal measured by the sensor can correspond to the position of the laundry carrying member. Furthermore, the invention relates to a method for operating the laundry dryer.

Description

Laundry dryer with acceleration sensor and method for operating the same

Technical Field

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

Background

The development of laundry dryers aims at designing a more reliable and easier operation for the user, as well as continuously improving the drying program implemented therein in terms of performance, time, energy consumption and environmental compatibility. For this purpose, the possibility of being able to determine the operation-related parameters at any time is essential.

For this purpose, laundry dryers are usually equipped with sensors, for example, sensors operating in a resistive or capacitive manner, which 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. This has the disadvantage that these sensors are usually arranged at different points in the laundry dryer, so that a high degree of inaccuracy of the measured sensor signal can result as a result of the detection of different measuring points by these sensors. Furthermore, the sensors usually require a large installation space, so that the arrangement cannot be designed flexibly, and in most cases a greater distance between the actual measurement object and the sensor results, and the sensor signal is inaccurate. It is therefore desirable to be able to realize a sensor arrangement in as small a construction space as possible.

The publication DE 102012217975 a1 describes a household appliance having a control device for controlling an operating process of the household appliance and a battery-less 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 to transmit a radio signal representing the at least one operating parameter wirelessly to the control device. The generator is a thermoelectric generator with two thermal contact surfaces, which is designed to provide electrical energy based on the temperature difference between the contact surfaces.

Publication EP 1895043 a1 describes a washing machine and/or laundry dryer, in particular for domestic use, which is equipped with a rotating drum for receiving the laundry to be washed and/or dried and with a control device capable of measuring 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 identified measurement variable. Here, the measuring device comprises an electric power generator directly associated with the rotating drum and communicating wirelessly with the control panel of the machine. The electric energy generator comprises a permanent magnet freely sliding 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 switchboard capable of finely controlling and sending voltage signals to a control panel of the machine.

Publication EP 1997951 a1 describes a laundry machine comprising a rotating drum with a front access opening. The washing machine further includes an electronic device adapted to the drum and a generator built into the drum for rotating the drum so as to generate electric power required for operating the electronic device.

The publications DE 10242144 a1 and WO 2004/022836 a2 describe a laundry dryer with a rotating drum for receiving the laundry to be dried, wherein the drum has sensor devices for determining a physical value inside the drum, the sensor devices are connected by signal transmission to a control device of the laundry dryer, and the connection of the signal transmission is designed wirelessly and contactlessly.

The publication DE 102006053274 a1 describes a method for determining the load of laundry in a loading chamber with an outlet opening of a laundry dryer, in particular a ventilated laundry dryer, wherein the absolute air humidity in the outlet opening of the loading chamber is measured, wherein the load in the loading chamber is determined by determining a maximum value and/or a 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 can be introduced, one or more deflectors (baffles) mounted on the inner surface of the drum, one or more sensors arranged in the drum and a main regulating unit controlling the washing or drying operation. In this case, an additional control unit is arranged in the deflection element, which converts the analog signal obtained by the sensor into a digital signal and transmits this signal to the main control unit. A temperature sensor directed towards the inside of the drum may be arranged on the surface of the deflector. Additional conditioning units may perform wireless transmission of signals.

Publication WO 2018/015214 describes a household appliance having a control device and at least one sensor node, which sensor node 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 one another, 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. 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. Furthermore, a method for operating the laundry dryer should be provided.

The solution of this object is achieved according to the invention by a laundry dryer and a method for operating the laundry dryer having the features of the respective preferred embodiments. Preferred embodiments of the laundry dryer according to the invention and of the method according to the invention are listed in the corresponding alternative. Even if not explicitly stated here, a preferred embodiment of the laundry dryer according to the invention corresponds to a preferred embodiment of the method according to the invention, and vice versa.

The subject matter of the invention therefore relates to a laundry dryer having: a control device; a drum for receiving laundry, in which at least one laundry carrier is arranged, wherein a sensor assembly having at least two sensors, an autonomous energy supply unit and an interface for wireless communication are located in the laundry carrier; and at least one evaluation unit for a sensor signal of the sensor arrangement, wherein the control device and the sensor arrangement are provided for wireless communication with one another, and an acceleration sensor, at least one electrode of 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 is rotating, so that the sensor signal measured by the conductivity sensor and/or the air humidity sensor can correspond to the position of the laundry carrier.

The laundry dryer can be the dryer itself or a washing dryer, i.e. an appliance which combines the functions of a washing machine and a dryer.

As acceleration sensor, for example, a capacitive sensor can be used. Sensors based on resistive load strips 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 invention, the acceleration sensor is a sensor with 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 imbalances 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.

In the case of the use of the acceleration sensor, the load of the drum and the slippage of the drum relative to the drive motor as well as the degree of unbalance of the drum can also be advantageously calculated and compensated for by the control device if necessary. Furthermore, the position and speed of the cylinder can be identified by the z-axis signal. In addition, aging effects, for example wear of the roller bearing or aging of the drive train, can also be detected by the acceleration signal and, if necessary, information can be output to the user by the control device.

In particular, the loading degree of the laundry in the drum can be accurately measured. Due to the rotation of the drum, the laundry collides with the laundry catch and acceleration pulses are generated in this way, 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 thereby increased with regard 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 the at least one laundry carrier, so that the conductivity between the at least two electrodes can be measured. The two electrodes can also be arranged on different laundry drivers. If the measured electrical conductivity between the two electrodes is relatively low, it can be concluded that there is no wet laundry between the electrodes. Depending on the arrangement and number of the electrodes, the load of the drum with wet laundry can be deduced from the corresponding sensor signals.

In a preferred embodiment of the laundry dryer, the counter electrode of the conductivity sensor is arranged on the same laundry carrier or on a different laundry carrier.

In an alternative embodiment of the laundry dryer, the drum housing of the drum is used as a counter electrode of 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 the laundry in the drum as a function of sensor signals measured by the conductivity sensor and/or the air humidity sensor. That is, different fillings of the drum are derived from the laundry amount, i.e., the load of laundry in the drum and the laundry humidity. This influences the washing situation during the rotation of the drum, wherein the rotational speed of the drum additionally influences the washing situation. At a constant rotational speed of the drum, the washing condition is related to the amount of laundry and the humidity of the laundry. Therefore, the drum housing area and the laundry catch are in contact with the laundry at different times while the drum is rotating. In order to identify at which point in the laundry conveyor the sensor signal of the air humidity sensor or the conductivity sensor is detected during the drum movement, the sensor signal of the acceleration sensor is evaluated, so that the sensor signal measured by the conductivity sensor and/or the air humidity sensor can correspond to the position of the laundry conveyor.

For this purpose, one of the measuring shafts of the acceleration sensor is usually arranged parallel to the axis of rotation of the drum, so that the angular position of the drum and thus the position of the associated laundry catch can be inferred from the values of the acceleration in the two other directions. The measured values of the air humidity and/or the electrical conductance can thus be made to correspond to the position of the drum. From the intensity of the sensor signal at this point, the load of the laundry and the laundry moisture of the laundry can be inferred. 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, the result is that the laundry catch comes into less contact with the laundry with a smaller laundry load. In the case of a smaller load, less laundry entrainment members come into contact with the laundry during rotation of the drum than in the case of a larger load. In addition, it is conceivable that the contact surface between the laundry and the laundry driving member becomes smaller as the degree of drying of the laundry increases.

According to the invention, the respective relationships are 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 them as accurately as possible.

In a preferred embodiment of the laundry dryer, at least two sensors of the sensor arrangement are based on the same measuring principle and are arranged along the laundry catch. The accuracy with which the laundry moisture and the laundry load can be determined by means of the invention can thus be further improved.

The laundry catch is usually arranged substantially parallel to the axis of rotation of the drum, so that the concept "along the laundry catch" is explained below, which arrangement is realized substantially parallel to the axis of rotation of the drum. In this arrangement, the sensors are at a distance from one another at least in the direction of the laundry conveyor, wherein the distance is usually determined in each case from a projection of the position of the sensors on an imaginary axis which extends parallel to the axis of rotation of the drum. Thus, the three sensors along the laundry conveyor determine two distances, i.e. a first distance d between the first sensor and the second sensor₁And a second distance d between the second sensor and the third sensor₂. Distance d₁And d₂May be the same or different. This applies correspondingly to the 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, so that the at least two sensors are each a temperature sensor, an air humidity sensor, a pressure sensor, a conductivity sensor 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 used optionally is a micromechanical temperature sensor, which is composed of n-type silicon crystals produced in planar technology.

Furthermore, it is particularly preferred according to the invention to use a multisensor as the sensor, which multisensor is based on a plurality of measurement principles simultaneously. Such space-saving double or triple sensors are known.

The at least two sensors of the laundry dryer preferably have a width of 2-4X 0.5-1.5mm, respectively³Modular members of a range of sizes.

The sensors are usually designed as micromechanical sensors. Since micromechanical sensors are particularly small components, i.e. require little structural space, two or more sensors can be assembled, so that, for example, a double sensor or a triple sensor is formed. For this purpose, the sensor can be constructed, in particular, in a modular manner. The compact design of the micromechanical sensor however also offers another decisive advantage. That is, if micromechanical sensors are used, all sensors may take measurements at the same location. The sensor signals all have a common location reference point. In this way, the parameters obtained from the individual sensor signals can be correlated particularly precisely with one another.

In any case, the sensor device, which comprises at least one micromechanical sensor, an interface for wireless data communication and an autonomous energy supply unit, and if necessary an evaluation unit, can be implemented on a particularly small installation space.

In a further preferred embodiment of the laundry dryer according to the invention, at least one sensor of the sensor arrangement arranged in the laundry carrier, for example a micromechanical sensor, is a pressure sensor having a diaphragm. The pressure exerted on the membrane by the laundry when it comes into 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. Due to the rotation of the drum, the laundry collides with the laundry catch and in this way a pressure acting on the laundry catch is generated, which can be detected by a pressure sensor. From the type and magnitude of the measurement signal, the degree of loading can then be determined.

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 the switching on of the tumble dryer in the event that the pressure sensor detects the sensor signal after the laundry has been introduced into the drum when the laundry dryer is switched off.

The invention can monitor the drying program in the described embodiment by evaluating the sensor signal of a sensor which is arranged in the direction of the laundry conveyor or in the direction of the rotational axis of the drum. When a drying program for wet laundry is usually carried out, process air flowing in a so-called process air duct flows from behind into the drum after it has been heated by the usually present heating device of the laundry dryer. While passing through the drum up to the front side, the process air, which is originally very hot and dry, gradually cools down and at the same time absorbs the moisture of the laundry to be dried. In addition, the laundry is pushed forward in the direction of the access door as a result of the flow of the process air. In this case, the laundry closest to the process air that has entered is usually dried to the greatest possible extent. Overall, therefore, a gradient of the temperature and humidity of the process air is produced in the direction of its axis of rotation in the drum. 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 program. This allows a better determination of the laundry moisture and the load of the laundry in the drum. Thus, non-uniformity in drying can be compensated for, for example, by appropriately varying the blower power, the heating power, and the drum rotation. It is also possible to more accurately determine a desired drying end.

In a particularly preferred embodiment of the invention, at least three sensors, preferably at least four and particularly preferably at least six sensors are thus arranged along at least one laundry catch. In general, these sensors are based on the same measurement principle, in order to be able to monitor changes in a characteristic, for example the air humidity, as accurately as possible in the direction of the axis of rotation or the laundry conveyor.

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

In addition to the sensors arranged in the drum in the laundry conveyor, additional sensors can optionally be arranged for replenishment in the process air line, for example at the drum inlet and/or at the drum outlet. The sensors can be based on different measuring principles, for example temperature, humidity, pressure, wherein double sensors and triple sensors can also be used. A sensor arranged outside the drum may additionally contribute to a better monitoring of the drying program.

A laundry dryer is furthermore 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 conveyor. In other words, in the case of a sensor arranged along the laundry catch, it can be determined when the drum rotates that the sensor signal changes from how far away it is from the entry opening of the drum, so that it can be attributed to no more laundry being arranged there.

The background for this is that different fillings of the drum can occur depending on the amount of laundry in the drum, i.e. the load of the drum and the humidity of the laundry. The laundry is pressed towards the dryer door when process air preferably enters at the rear wall of the drum. Depending on the amount of laundry in the drum, only the front region of the drum can then be filled in the event of entry of the drum. In addition, in this preferred flow direction of the process air, the laundry is dried more quickly at the drum inlet than at the drum outlet. The invention can be implemented in that the filling level and the humidity of the laundry, i.e. the drying level of the laundry, are identified as a function of the drum depth, i.e. as a function of the position along the laundry conveyor. The drying status and load of the laundry can thus be determined more accurately and the drying program can thus be arranged more accurately.

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 for determining the load of the laundry in the drum and/or the degree of drying of the laundry. Here, the intensity 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 channel of the laundry dryer.

According to the invention, the laundry dryer preferably has at least two laundry drivers, in which the sensor arrangement with the at least two sensors, the autonomous energy supply unit and the interface for wireless data communication are located. In this case, it is also preferred that the control device of the laundry dryer is provided for determining the load of the laundry in the drum, taking into account the rotational speed of the drum, on the basis of sensor signals measured by the sensor arrangement in the at least two laundry carriers and/or of the position gradient of the sensor signals in the direction of the laundry carriers. If at least two laundry drivers each have an acceleration sensor, then the local position of the acceleration sensor can also be taken into account during the rotation of the drum.

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

In the laundry dryer according to the invention, the wireless communication between the control device and the at least one sensor arrangement can preferably take place in both directions. That is, in one embodiment, a sensor signal group which is detected independently by the sensor arrangement and then evaluated can be transmitted, for example, to the control device. Furthermore, the control device can preferably also transmit signals to the sensor arrangement, for example for polling the sensor signals. In this case, the control device is preferably provided for carrying out an action in the laundry dryer as a function of the sensor signal transmitted by the at least one sensor arrangement 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 invention. That is, the action may be, for example, to execute a drying program or also to execute a part of a drying program. The drying program in the sense of the present invention can be a drying program set by the factory in the laundry dryer, one or more additional options or also a user-defined drying program. Therefore, the term drying course is broadly construed according to the present invention. In addition, the action can also be in the sense of the invention a simple switching on or off of the laundry dryer, a switching on or off of the heating device or process air blower of the laundry dryer or a change in the power thereof, a display output on an operating element of the laundry dryer or a sound signal for the purpose of outputting information to the user.

In any case, the term "action" includes any possible way of controlling the laundry dryer according to the invention.

In the laundry dryer according to the invention, the control device and the at least one sensor assembly are provided for wireless data communication. Preferably, the at least one sensor arrangement and the control device and/or the evaluation unit are provided for wireless communication with each other via a low-power bluetooth connection. In this case, 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, it is provided that the at least one laundry driver comprises an autonomous energy supply unit. According to the invention, the term "self-sufficient energy supply unit" is used herein to mean that the energy supply unit is provided for generating energy independently, i.e. independently of the energy supply device of the laundry dryer.

When the laundry dryer is switched off, the sensor device can then also independently detect and evaluate the sensor signal in the manner described and transmit said sensor signal to the control device. The manner of energy supply is not limited herein. However, the energy supply can also be realized thermoelectrically, inductively or piezoelectrically, for example. In this case, in principle, any method known from the prior art is possible. In addition, batteries or accumulators may also be used for the power supply.

If the energy supply unit comprises a thermopile element, at least one thermopile element may be arranged in or on the laundry catch. In contact with hot washing or also due to hot process air, a temperature difference can then occur at both ends of the thermopile element. The resulting voltage difference can then be tapped off at one end.

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

In an alternative embodiment, the magnet can also be arranged in the laundry carrier, or rather can be moved such that it can pass by the adjacent coil when the drum is moved upwards and downwards. In this way, the energy supply unit can also be integrated completely into the laundry catch.

In a preferred embodiment of the invention, the autonomous energy supply unit comprises at least one piezoelectric element for generating energy and is provided for generating energy for the sensor arrangement, 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 an electrical quantity is generated by mechanical deformation.

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

The shape of the bending element is not limited according to the invention, but the bending element can have any geometric shape. However, the bending element is preferably of flat design, particularly preferably of rectangular design. The size and amount of deflection of the bending elements is not limiting according to the 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 piezo-ceramic bender typically includes a bender structure and electrodes. The curved structure can be realized in different ways, for example as a layered structure. The meander structure can also be a combination of one or two piezo ceramic elements, which can also have at least one intermediate layer. The piezoceramic component can also be formed here from a single layer and/or a plurality of layers, the layer thicknesses of which are likewise not limited.

The piezoceramic material is also not restricted according to the invention, which may be, for example, lead zirconate titanate, although any other piezoceramic may also be used.

In a preferred embodiment of the laundry dryer according to the invention, in each case optionally used piezoceramic bending elements have a piezoceramic layer with a layer thickness of 100 to 500 μm. The layer thickness is preferably in the range from 150 to 250 μm, for example 200 μm.

Preferably, the layer is then designed as a plate and has surface electrodes on the top side and the bottom side, respectively, and contacts and two electrical connections, respectively.

In a preferred embodiment of the laundry dryer according to the invention, the at least one optional piezoelectric element is arranged in or on the laundry catch so that it can be deformed by the laundry hitting the at least one laundry catch during rotation of the drum. Preferably, the energy supply unit is completely integrated into the laundry carrier, so that the sensor assembly can be made as a compact modular assembly together with the energy supply unit.

In general, laundry dryers also have at least one display unit which can display 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 via a display unit. Very particularly preferably, the display unit is an external display unit, for example a touch screen of a smartphone or tablet computer.

The laundry dryer comprises an evaluation unit for evaluating the sensor signal. The evaluation unit can be arranged in the laundry conveyor or elsewhere in the laundry dryer. The type and configuration of the evaluation unit are not limited. The evaluation unit can, for example, be part of at least one sensor, i.e. be arranged in the 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 signal and for transmitting said sensor signal to the control device.

In a preferred embodiment of the laundry dryer according to the invention, an evaluation routine is also stored in the evaluation unit, and the evaluation unit is provided for not only calculating, but also evaluating and transmitting to the control device if this is the case according to the evaluation being preset, for example on the basis of a setpoint value/actual value comparison and/or on the basis of a calibration value/calibration curve of the 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 having 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 smartphone 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 accumulator. The energy storage device is not restricted according to the invention and can be realized technically in any way, i.e. for example as a battery. Furthermore, the energy store can be provided, for example, in the piezoelectric element or also be designed separately. In any case, the energy storage device serves to store the energy generated by the energy supply unit and, if necessary, to supply the sensor assembly and, if necessary, the evaluation unit or the like with electrical energy.

The subject matter of the invention is also a method for operating a laundry dryer, having; a control device; a drum for receiving laundry, in which at least one laundry carrier is arranged, wherein a sensor assembly having at least two sensors, an autonomous energy supply unit and an interface for wireless communication are located in the laundry carrier; and at least one evaluation unit for a sensor signal of the sensor arrangement, wherein the control device and the sensor arrangement are provided for wireless communication with one another, and an acceleration sensor, at least one electrode of a 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 is rotating, so that the sensor signal measured by the conductivity sensor and/or the air humidity sensor can be assigned 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 of the air humidity sensor; and

(d) evaluating a sensor signal of a sensor of the sensor assembly used in step (b) with respect to the load of the laundry in the drum and/or the degree of drying of the laundry by an evaluation unit, wherein the sensor signal measured by the conductivity sensor and/or the air humidity sensor is made to correspond to the position of the laundry carrier, and the evaluation result obtained here 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 usually present display unit for the user of the laundry dryer. For example, the drying program may be modified to more efficiently and/or more uniformly dry. Alternatively or additionally, the drying end can also be displayed in more detail on a display unit of the laundry dryer.

In the process air line of a laundry dryer, a blower for conveying the process air is usually present. In a preferred embodiment of the method according to the invention, therefore, a blower is arranged in the process air line 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 the measured intensity of the air flow is taken into account when evaluating in the following step (d).

In the method according to the present invention, step (b) may preferably be initiated not only by the control means, but also independently by the sensor means, without being initiated by the control means. That is to say, the control device can transmit a signal to at least one sensor component, for example, in order to detect a sensor signal, and thus start step (b) of the method according to the invention. However, it is also possible, for example, to store a routine in the evaluation unit in order to initiate the measurement independently and thus start step (b) of the method according to the invention.

The present invention has many advantages. By measuring various physical properties in the drum of the laundry dryer in a position-dependent manner, the drying program can be optimized better as a function of the position of the laundry carrier in the rotation of the drum or, in the embodiment of the invention, additionally in the direction of the laundry carrier, in such a way that the degree of drying of the laundry and the load of the laundry can be inferred precisely. Furthermore, the information can be transmitted from the drum in a convenient manner, i.e. wirelessly. In the embodiments of the invention, the use of micromechanical sensors makes it possible to design the sensor assembly particularly flexibly and in a space-saving manner. In this case, a plurality of different sensor types can be provided in variable numbers in the sensor arrangement. Furthermore, it is particularly advantageous that, due to the small design of the micromechanical sensor, all measurement signals can be detected in a position-dependent manner at the same measurement location. This makes it possible to associate all values particularly precisely. Furthermore, no electrical or mechanical contact between the control unit and the sensor assembly is required by the self-sufficient energy supply unit. Furthermore, the use of a low power wireless interface in embodiments ensures a long service life in alternative battery operation due to low power consumption.

Drawings

Further details of the invention emerge from the following description of a non-limiting embodiment. Reference is made herein to fig. 1 and 2.

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

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

Detailed Description

Fig. 1 shows a vertical section through a laundry dryer according to the invention, which is designed 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 which is rotatable about a horizontal axis for receiving laundry to be dried, not shown here, and in the interior of which a

driver

5, 22 for moving the laundry during rotation of the drum is mounted. Process air is conducted through the drum 3 in the process air duct 2 by means of a process air blower 6 via an air-air heat exchanger 14 and an electric heater 4. The air heated by the electric heater 4 is guided into the drum 3 through the drum inlet 19 from behind, i.e. from the side of the drum 3 opposite the door 12, through the perforated bottom of the drum.

After being discharged from the drum 3, the moisture-laden process air flows through the filling opening of the drum 3 through a fluff screen inside a door 12 which closes the filling opening. The process air flow then passes downward in the door 12 through the drum outlet 18 into the process air duct 2 and is conducted 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. A greater or lesser part of the moisture absorbed by the process air from the laundry is condensed in the air-air heat exchanger 14 on the basis of cooling and collected in the condensate basin 17.

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

In each case two

laundry carriers

5, 22 of the laundry dryer 1 shown here, there are a sensor arrangement 23, which is designed here as 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 the sensor signals of the sensor arrangement 23, wherein the control device 8 and the sensor arrangement 23 are provided for wireless communication with one another. The communication can take place via the evaluation unit 30 connected in between. The

triple sensors

24, 25, 26, 27 of the sensor arrangement are based on the same measuring principle (temperature, pressure, humidity) and are arranged along the

laundry catch

5, 22.

However, the

sensors

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

According to the invention, it can be determined, using the acceleration sensor 31, from the measured sensor signal whether the laundry catch in the determined angular position is still in contact with the laundry or is 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 to more accurately design the drying program. For this purpose, 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 each measure the relative air humidity, temperature and air pressure of the process air 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 determined better. For this reason, a timing device 20 is also present in the condensation dryer.

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

The display unit 21 enables the remaining operating time of the drying program, for example of ironing, to be displayed in relation to the residual moisture value of the laundry selected by the user, or the measured load or other state of the laundry dryer to be displayed or the status of the drying program to be displayed, for example in the form of a color distinction.

Fig. 2 shows a detail of the drum, wherein the laundry catch with the sensor system arranged therein is shown enlarged.

In particular, the partial illustration of a sectional view of a part of the drum of the laundry dryer 1 of fig. 1 shows the

laundry carrier

5, 22 arranged on the drum and having a sensor arrangement with a self-sufficient energy supply unit 28. In the sectional view, only the acceleration sensor 31 and the triple sensor 24 (pressure, temperature, humidity) can be seen 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 catch 9, 22.

List of reference numerals

1 drying machine

2 process air duct

3 roller

4 (electric) heater

5 first driver

6 process air blower, blower

7 operating unit

8 control device

9 sensor for measuring the temperature, relative humidity and/or air pressure at the drum outlet

10 sensor for measuring temperature, relative humidity and/or air pressure at the drum inlet

11 fluff filter screen

12 door, entry door to drum

13 a variable speed drive motor; in particular a BLDC motor

14 heat exchanger; in particular air-air heat exchanger

15 cooling air duct

16 Cooling air blower

17 condensation basin

18 drum outlet

19 roller inlet

20 timing device and clock

21 (optical) display unit

22 second washings driver

23 sensor assembly

24 a first sensor; single, double or triple sensors

25 a second sensor; single, double or triple sensors

26 a third sensor; single, double or triple sensors

27 a fourth sensor; single, double or triple sensors

28 self-sufficient energy supply unit

29 interface for wireless data transfer, bluetooth low energy interface

30 evaluation unit

31 acceleration sensor.

Claims

1. Laundry dryer (1) having: a control device (8); a drum (3) for receiving laundry, in which at least one laundry carrier (5, 22) is arranged, wherein a sensor arrangement having 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 carrier (5, 22); and at least one evaluation unit (30) for a sensor signal of the sensor arrangement (23), wherein the control device (8) and the sensor arrangement (23) are provided for wireless communication with one another, characterized in that an acceleration sensor (31) and at least one electrode of a conductivity sensor (24, 25) and/or an air humidity sensor (26) are arranged in the laundry carrier (5, 22), and the control device (8) is provided for determining the position of the laundry carrier (5, 22) during rotation of the drum (3), so that the sensor signal measured by the conductivity sensor (24, 25) and/or the air humidity sensor (26) can be assigned to the position of the laundry carrier (5, 22).

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

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

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

5. Laundry dryer (1) according to any of claims 1 to 4, characterized in that the control device (8) is provided for determining the laundry humidity and/or the load of the laundry in the drum (3) from the sensor signal measured by the conductivity sensor (24, 25) and/or the humidity sensor (26).

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

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

8. Laundry dryer (1) according to any of claims 1 to 7, characterized in that at least three sensors (24, 25, 26, 27) are arranged along the at least one laundry carrier (5, 22).

9. Laundry dryer (1) according to any of claims 1 to 8, characterized in that as sensor a multiple sensor is used, which is simultaneously based on multiple measuring principles.

10. Laundry dryer (1) according to any of claims 1 to 9, characterized in that the control device (8) is provided for determining the laundry load in the drum (3) and/or the degree of drying of the laundry as a function of the sensor signal measured by the sensor and/or the position gradient of the sensor signal in the direction of the laundry carrier (5, 22).

11. Laundry dryer (1) according to claim 10, characterized in that said control means (8) are provided for taking into account the intensity of the air flow entering inside the drum (3) in order to determine the load of laundry in the drum (3) and/or the degree of drying of the laundry.

12. Laundry dryer (1) according to any of claims 1 to 11, characterized in that the laundry dryer has at least two laundry drivers (5, 22), in which a sensor assembly (23) with at least two sensors (24, 25, 26, 27), an autarkic energy supply unit (28) and an interface (29) for wireless data communication are located.

13. Laundry dryer (1) according to any of claims 1-12, characterized in that said at least one sensor assembly (23) and said control device (8) and/or said evaluation unit (30) are provided for communicating wirelessly with each other by means of a low-power bluetooth connection.

14. Method for operating a laundry dryer (1), the laundry dryer (1) having: a control device (8); a drum (3) for receiving laundry, in which at least one laundry carrier (5, 22) is arranged, wherein a sensor arrangement having 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 carrier (5, 22); and at least one evaluation unit (30) for a sensor signal of the sensor arrangement (23), wherein the control device (8) and the sensor arrangement (23) are provided for wireless communication with one another, 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 at least one laundry carrier (5, 22), and the control device (8) is provided for determining the position of the laundry carrier (5, 22) during rotation of the drum (3) such that the sensor signal measured by the conductivity sensor (24, 25) and/or the air humidity sensor (26) can be assigned to the position of the laundry carrier (5, 22), 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 of the air humidity sensor (26); and

(d) evaluating sensor signals of sensors (24, 25, 26, 27, 31) of the sensor arrangement (23) used in step (b) with respect to the laundry load in the drum (3) and/or the degree of drying of the laundry by means of the evaluation unit (30), wherein the sensor signals measured by the conductivity sensors (24, 25) and/or the air humidity sensor (26) are assigned to the position of the laundry conveyor (5, 22) and the evaluation results obtained in this case are transmitted to the control device (8).

15. Method according to claim 14, characterized in that a blower (8) is arranged in the process air duct (2) of the laundry dryer (1) and that the following step (c) is carried out before step (d):

(c) the intensity of the air flow entering the drum (3) is measured and the measured intensity of the air flow is taken into account when evaluating in the following step (d).