EP4074216B1 - Method for detecting the occupancy state of at least one piece of furniture in form of a table - Google Patents

Description

The invention relates to a method for detecting the occupancy status of at least one piece of furniture in the form of a table.

Pieces of furniture are known, such as office desks, which have a height-adjustable tabletop resting on support feet. Electric motors are integrated in the table bases for motor-assisted height adjustment of the table top. Such a piece of furniture is, for example, in the WO 2010/112574 A2 described.

From the DE 20 2016 104 512 U1 an electrically adjustable piece of furniture with a drive unit for adjusting a furniture adjustment section relative to a furniture support section is known. The piece of furniture has a sensor device for detecting the inclination or the change in inclination of the furniture adjustment section, the drive unit being able to be controlled as a function of the inclination or change in inclination. This makes it possible, for example, in the case of an embodiment of the piece of furniture as a height-adjustable table Grasp and push up or down on the edge of the table to set a desired height.

The U.S. 5,819,669 A discloses an adjustable desk whose height can be adjusted with respect to lateral support feet by means of an electric drive motor.

The drive motor is designed as an AC motor that is powered by mains current. The drive motor is located on a side support foot.

The U.S. 6,352,037 B1 shows an adjustable table with four side table legs, compared to which the table top is adjustable in height. Supports are arranged on the underside of the table top and extend telescopically into the table legs. The height of the table top can be adjusted via a common drive motor with mains connection.

The DE 10 2016 102 382 A1 discloses a control method for height adjustment of an electrically adjustable table. The height of the table is raised when a movement sensor unit detects that the tabletop is tilting during height adjustment. This prevents the table top from being raised any further if the table top hits an obstacle.

The EP 0 671 145 A1 discloses a sensor device for beds for monitoring sick or infirm persons. The sensor device comprises two parallel plates which are located at a small distance from each other, the upper plate taking the weight of the person at rest. A deflection of the upper plate can be detected by a sensor which generates a signal indicating the presence of the person lying on the bed.

For further prior art on the U.S. 5,614,811A referred.

The object of the invention is to detect the occupancy status of at least one piece of furniture in the form of a table.

The invention relates to a method for detecting the occupancy status of at least one piece of furniture in the form of a table. The piece of furniture is equipped with a sensor device for detecting a movement of a furniture section of the piece of furniture.

The occupancy status of the piece of furniture refers to whether the piece of furniture is occupied by a person or has been occupied by a person or not. According to the invention, the occupancy status of a piece of furniture as a table, for example as a height-adjustable table, means that a person is sitting or standing at the table and thereby occupies the table.

In the method, a movement of a piece of furniture is detected with the aid of a sensor device, which is preferably integrated into the piece of furniture.

The detected movement is recorded as a relative movement via the sensor device. The furniture section whose movement is detected forms a furniture adjustment section that can be adjusted relative to a furniture support section of the piece of furniture.

The movement is detected by the sensor device over a limited or indefinite period of time, as a result of which a movement pattern of the furniture section can be determined. This movement pattern of the furniture section is compared with a reference movement pattern. If the detected movement pattern of the furniture section corresponds to the reference movement pattern, it must be assumed that the piece of furniture is occupied, which means that the piece of furniture is occupied by a person. In this case, a corresponding occupancy signal is generated.

With the help of this method, the state of movement of a piece of furniture to which a sensor device is assigned can thus be automatically recognized. The piece of furniture has at least one furniture adjustment section and one furniture support section, with the sensor device detecting the movement of the furniture adjustment section relative to the furniture support section.

The occupancy signal can then be further processed centrally or decentrally and used, for example, to control one or more technical devices that are located either in the piece of furniture or in the vicinity of the piece of furniture. For example, when a piece of furniture is occupied, it is possible to control one or more light sources in the piece of furniture or outside of the piece of furniture, to regulate the room temperature to a defined value, or the like. It is also possible to allocate an unoccupied piece of furniture to a person who is looking for a place to sit or work.

In a preferred embodiment, the sensor device is located in the piece of furniture. In order to detect a relative movement, the sensor device can be arranged either in the furniture adjustment section or in the furniture support section or in both sections of the piece of furniture. It is possible to determine either an immediate relative movement of the furniture adjustment section in relation to the furniture support section or a movement of the furniture adjustment section in relation to the floor or another surrounding object, with the furniture support section standing firmly on the floor, so that conclusions can be drawn about the relative movement between the furniture adjustment section and the furniture support section .

Various options for relative movement of the furniture adjustment section in relation to the furniture support section can be considered. According to an advantageous embodiment, the inclination of the furniture adjustment section relative to the furniture support section can be changed, for example the inclination of a tabletop, which is part of a furniture adjustment section of a table, relative to one Support base of the table, for example one or more table legs. By observing the inclination over a period of time, the change in inclination of the furniture adjustment section can be determined and compared with a reference movement pattern.

According to the invention, the movement of the furniture section—relative to the furniture support section—is continuously monitored and a comparison is made with the reference movement pattern as soon as movement of the furniture section is detected over a minimum period using the sensor device.

In general, this procedure has the advantage that, in particular, already existing sensor devices in the piece of furniture or outside the piece of furniture can be used to detect the occupancy status. All sensor devices are suitable with which a relative movement of the furniture adjustment section in relation to the furniture support section or an absolute movement of a furniture section can be sensed. By capturing the movement over a period of time, a movement pattern of the furniture section is obtained, which can be compared to the reference movement pattern.

By defining a reference movement pattern for comparison with the sensed movement pattern, it is possible to distinguish between a movement that indicates the occupancy state and any other movement of the furniture section. When the piece of furniture is occupied by a person, a characteristic movement pattern arises in the furniture section, which senses using the sensor device and then with the Reference movement pattern can be compared. The movement pattern that is characteristic of an occupied piece of furniture differs from other movements of the furniture section that are intentionally brought about by the person occupying it. In this respect it is possible with the same sensor device to set a defined position of the furniture section automatically or triggered manually, to detect a collision with another object and also to detect the occupancy status of the piece of furniture.

The piece of furniture has at least one electric drive motor for adjusting the furniture adjustment section relative to the furniture support section. The movement pattern of the furniture adjustment section, which is used to detect the occupancy status, is sensed during a rest phase of the electric drive motor.

According to a further expedient embodiment, the occupancy status of several pieces of furniture is recorded. The occupancy signals of one or more pieces of furniture are advantageously fed to a central location in which further processing of the occupancy signals takes place, for example the activation of one or more technical devices as a function of the occupancy signal. In particular, it is also possible to assign a piece of furniture that is not occupied to a person. It is thus possible to use the occupancy signal in the central office to detect the occupancy status of one or more pieces of furniture and non-occupied pieces of furniture of a person in each case to assign. This procedure makes it possible, for example, to carry out a variable assignment in companies instead of a fixed assignment of a workplace to a specific person, which enables a higher degree of occupancy of the pieces of furniture.

The sensor device can include, for example, a high-resolution gyro sensor, via which a rotation or change in angle of the furniture adjustment section relative to the furniture support section can be determined. Additionally or alternatively, the sensor device can also include a gravitational sensor, via which the absolute inclination of the furniture adjustment section in space can be determined. The height of the furniture adjustment section can be determined via a distance sensor of the sensor device, which measures the distance from the floor, from a reference or from the ceiling. Alternatively, the height of the furniture adjustment section can be determined via a Hall sensor which is arranged in the drive motor. The sensor device can have one or more sensors for motion detection.

The sensor device can be part of a control device with a controller in which the control signals of the sensor device are processed and control signals are generated for controlling one or more drive motors via which the furniture adjustment section is adjusted. The control device can be integrated into a drive, which includes the drive motor and a gear and possibly connection or transmission components, or it can be arranged outside of the drive. Furthermore, it is possible to integrate the sensor device into the controller, with the sensor device possibly also being outside of the controller can be arranged. The controller can be attached to the furniture adjustment section or to the furniture support section.

If the occupancy status of several pieces of furniture is detected, the occupancy signals are preferably fed to a common central location. The occupancy signals of each piece of furniture are transmitted to the central station either via transmission cable or wirelessly. The evaluation of the signals and the allocation of persons to unoccupied pieces of furniture and/or the activation of one or more technical devices, which are located either in the pieces of furniture or outside of the pieces of furniture, in particular in the vicinity of the pieces of furniture, advantageously takes place in the central office.

A further aspect which does not belong to the invention relates to an electrically adjustable piece of furniture which has one or more electric drive motors which are used to adjust at least one furniture adjustment section relative to a furniture support section of the piece of furniture. The furniture adjustment section can be adjusted at a higher speed than the furniture support section.

The piece of furniture can optionally have a sensor device with which the relative or absolute position or a relative or absolute movement of a furniture section, for example the relative position or a relative movement of the furniture adjustment section in relation to the furniture support section, can be detected, with the at least one electric Drive motor can be controlled depending on the detected position or movement of the furniture section.

At least one drive motor in the electrically adjustable piece of furniture, preferably all of the electric drive motors, is designed as an electric motor that can be operated directly with the mains voltage of the household electricity network. It is therefore not a drive motor that does not have the necessary electrical insulation to be connected directly to the household electrical network; Rather, the mains voltage of, for example, 230 V without galvanic isolation between the household power supply and the drive motor is used directly and without a transformer that causes galvanic isolation from the household power supply. If necessary, the drive motor can be operated via corresponding power electronics with a lower voltage than the household voltage.

Galvanic isolation is the avoidance of electrical conduction between the household power supply and the drive motor. In the context of the present invention, the omission of galvanic isolation means that the drive motor or the power electronics of the drive motor are conductively connected to the domestic power supply system.

Since the power is no longer limited by a power supply unit in this embodiment, a significantly higher power can be generated in the drive motors, which means, for example, greater travel distances and higher travel speeds of the furniture adjustment section in relation to the furniture support section can be realized. Also it is possible to move the furniture adjustment section via the drive motor with higher loads in shorter periods of time than is possible with low-voltage drive motors that require a power supply for galvanic isolation, the performance of which is limited by the power of the power supply.

Another advantage of the drive motor(s) is that, in contrast to low-voltage drive motors with galvanic isolation, only relatively small power packs are required to control the drive motor, which reduces standby losses or eliminates them entirely. The size of the drive motor controller can also be significantly smaller, since the drive motors used, which do not require galvanic isolation, only require the output stages for controlling the drive. The cooling capacity is also significantly lower than with low-voltage drive motors, since the controller gives off less heat due to its different and smaller design. Due to the lower losses, a higher overall efficiency is achieved.

The smaller size of the controller, among other things, makes it possible, for example, to arrange the controller in a space-saving manner, eg in a motor box at the top of a table leg or at a point where the operating parts are usually arranged. It is also advantageous that the number of drives that can be connected to a controller can be scaled as required, since the number of drives is no longer limited by the power supply unit. Due to the lower thermal development, significantly longer switch-on phases of the drive motor can be used, even at high temperatures Realize loads or switch-off phases are no longer required.

The piece of furniture advantageously has at least two electric drive motors for adjusting the furniture adjustment section. According to an advantageous embodiment, these can be controlled independently of one another. All of the drive motors are designed in particular as electric motors that can be operated with mains voltage. It may be expedient to provide a common controller for the at least two electric drive motors.

If several drive motors are used, it may be necessary to synchronize the drive motors during the adjustment in such a way that a certain surface of the piece of furniture, e.g. the tabletop of a table, remains flat during the movement. By evaluating sensor signals from a sensor device, it is possible to control the drive motors in such a way that they run synchronously, for example by keeping the table top level.

For example, sensor devices with a gyro sensor and a gravitational sensor can be used. The signals from the gyro sensor and the gravity sensor, which outputs an absolute inclination value, are combined here. The height of the furniture adjustment section can be determined using an additional distance sensor that measures the distance to the floor, to a reference or to the ceiling.

The independent controllability of the electric drive motors allows a simple structure, especially in the way that the different electric Drive motors are supplied with different sensor signals. A desired tilted position of the adjustable furniture adjustment section relative to the furniture support section can also be maintained in this simplified embodiment. One of the electric drive motors performs a compensating movement automatically and independently of the other drive motor. An inclination or change in inclination of the furniture adjustment section is already detected via the sensor device during the movement of the furniture adjustment section and is compensated for by a corresponding activation of the associated electric drive motor.

It is thus possible, for example, to equip the furniture adjustment section, for example a table top, with two electric drive motors, of which a first electric drive motor is controlled in such a way that a desired speed is maintained. The second electric drive motor is controlled via sensor signals in such a way that a desired inclination of the furniture adjustment section is maintained. The sensor signals indicate the current status of the furniture adjustment section on the position and/or speed level.

The sensor signals for the first drive motor come, for example, from Hall sensors, via which both the current height and the speed are determined. The drive motor is then controlled in such a way that it maintains a desired speed. The second drive motor does not have a Hall sensor, but is controlled via the signals from a gyro/gravitation sensor located on the first drive motor or in the controller in such a way that the Möbelverstellabschnitt maintains a desired inclination, for example, a table remains straight. If the gyro/gravity sensor is already present for collision detection, no Hall sensors including cables, plugs and evaluation electronics are required for this drive motor and possibly for other drive motors.

An embodiment not according to the invention with a so-called master leg is also possible, on which a drive motor to be actuated by the operator is arranged, whereas the other legs are equipped with drive motors, each of which has its own controller and a gyro/gravitational sensor and automatically one set the desired inclination of the furniture adjustment section so that e.g. the table remains straight by having these drive motors carry out the movement required for the desired inclination.

Both versions not according to the invention, in which each electric drive motor is assigned its own separate controller, and versions not according to the invention with a common controller for at least two electric drive motors come into consideration. Independent control of the various electric drive motors is possible both in the embodiment with separate controllers that is not according to the invention and in the embodiment with a common controller that is not according to the invention.

In yet another embodiment not according to the invention, there is only one drive motor, the actuating movement of which can be transmitted via a transmission device to different parts of the furniture adjustment section or to a plurality of furniture adjustment sections. It is, for example, exactly one drive motor for the Height adjustability of a table used, the movement of the drive motor can be transmitted to two table legs via the transmission device.

In a further embodiment not according to the invention, the at least one electric drive motor can be switched on and off via an operating unit which is integrated in the housing of the controller which controls the electric drive motor. The operating unit can be inserted into the housing of the controller as a prefabricated structural unit, with the insertion advantageously simultaneously reaching a position in which mechanical contact with switches on a circuit board of the controller is possible. The operating unit has operating elements such as operating buttons to be operated manually by a user, the operating elements turning on and off the switches on the circuit board of the controller. For this purpose, the actuating elements are provided with extensions, which in particular are long enough to maintain a sufficient distance of, for example, 6 mm from the mains voltage circuit board of the controller.

Alternatively, the housing of the controller and/or the operating unit can be made of a material that allows direct contact with live components. In this case, a smaller distance between the operating elements of the operating unit and the mains voltage circuit board of the controller may also be sufficient.

It can be expedient to construct the housing of the controller, which is preferably made of plastic, with a relatively high wall thickness to improve stability, for example with a wall thickness of at least 2 mm. The increased stability of the controller housing ensures that the housing is not destroyed under the loads that usually occur, for example in the case of a height-adjustable table withstand loads that occur if the controller accidentally hits an object such as a Chair back or the like can occur.

As an alternative to actuating elements which actuate switches on the circuit board of the controller in a mechanical manner, the operating unit can be provided, for example, with capacitive control panels which are actuated by the user. The change in capacitance upon actuation serves as a signal for switching the electric drive motor on and off.

According to yet another embodiment not according to the invention, the operating unit for switching the drive motor on/off comprises a light source and a phototransistor, or the operating unit interacts with a light source and a phototransistor. LED or IR-LED, for example, is used as the light source. The light source can be directed in the direction of a control panel of the control unit, with the emitted light being reflected, for example, by a finger on the control panel, which is registered by the phototransistor.

In this embodiment, which is not according to the invention, the operating unit is advantageously transparent or at least semi-transparent in order to be able to conduct light for the light emitted by the light source. This design has the advantage that the controller in the housing is hermetically sealed to the outside.

For example, the LED and the phototransistor sit on the controller board.

It is also possible to guide the light from the light source to the operating unit via a light guide. This makes it possible to bridge greater distances with the help of the light guide, so that the operating unit can be positioned at a greater distance from the controller.

According to yet another embodiment not according to the invention, the operating unit is provided with a display on which a current parameter of the furniture adjustment section is shown, for example the current table height.

In a further embodiment not according to the invention, the operating unit for switching the drive motor on/off comprises a radio module for signal transmission to the controller or interacts with such a radio module. The radio module uses Bluetooth, BLE or WiFi, for example. This design has the advantage that an electrical cable, which would have to be electrically isolated for safety reasons, can be dispensed with. It is actuated, for example, via a remote control or via a smartphone.

According to yet another embodiment not according to the invention, the controller has a communication port for configuring, wherein the configuration takes place via an external device that can be connected to the controller, for example via a connected personal computer. If necessary, an interface element that contains the galvanic isolation can be plugged into the communication port.

According to a further advantageous embodiment, the controller can be controlled via a PWM signal with one low-side MosFet per direction of rotation, with the high-side being controlled with one thyristor per direction of rotation and the thyristor in turn via an optotriac or opto Thyristor is controlled. As a result, a full bridge for the electric drive motor to be controlled can be produced with relatively little effort.

In order to identify the current parameter of the furniture adjustment section, for example to identify the current table height, it can be advantageous to equip the drive motor with a signal transmitter for detecting the current number of revolutions. Two Hall sensors can be used for this purpose, for example, which detect a magnetic field that is generated by a magnet arranged on the motor or drive shaft. It is also possible to determine the direction of rotation by using two Hall sensors.

In an alternative embodiment not according to the invention, it is possible to use only a single sensor, for example a Hall sensor or a light barrier. The Hall sensor interacts with a magnet, which is advantageously magnetized in such a way that a pole change at a short distance is followed by a pole change at a short distance, and then a Long-distance polarity change. This makes it possible to detect the direction of rotation. In the case of a light barrier, this is associated with a disk on the motor or drive shaft which has openings of different lengths, for example one longer opening and two shorter openings in succession in the circumferential direction. Here, too, it is possible to detect the direction of rotation with just one light barrier.

According to yet another embodiment not according to the invention, the drive motor is equipped with a counter that counts the number of revolutions in the motor, from which the current position and thus the current parameter of the furniture adjustment section, such as the table height, can be determined. The counter must be compared with a reference in order to be able to determine the current parameter from the counter value. The comparison with the reference can already take place during assembly, for example.

According to a further embodiment not according to the invention, an interface is arranged between the controller and the drive motor, which interface communicates with the counter in the drive motor. This makes it possible to evaluate pulses originating from the drive motor, with both a recognition of the pulses including the execution of the pulse length for detecting the direction of rotation and an evaluation of the absolute parameter, for example the absolute height specification, being possible.

In a method for operating one or more pieces of furniture, which are each equipped with one or more electric drive motors as described above, which are operated with mains voltage, at least two electric drive motors can be synchronized in the same or in different pieces of furniture via the mains. This makes it possible to carry out synchronization even over longer distances without communication lines.

Universal motors, permanent magnet motors or brushless direct current motors are used as the drive motor, which is operated directly with mains voltage, i.e. without galvanic isolation.

Fig. 1

ausschnittsweise in Seitenansicht als verstellbares Möbelstück einen Tisch, wobei die Tischplatte über einen elektrischen Antriebsmotor gegenüber einem Tischbein höhenverstellbar ist,

Fig. 2

der Tisch gemäß Fig. 1 mit angehobener Tischplatte,

Fig. 3

in Seitenansicht ein vollständiger Tisch mit jeweils einem elektrischen Antriebsmotor im linken und rechten Tischbein,

Fig. 4

eine schematische Darstellung mehrerer Tische mit der Übertragung des Belegungszustandes jedes Tisches an eine Zentraleinheit,

Fig. 5

eine perspektivische Ansicht eines Controllers zur Ansteuerung eines elektrischen Antriebsmotors,

Fig. 6

einen Schnitt längs durch den Controller.

Further advantages and expedient embodiments can be found in the further claims, the description of the figures and the drawings. Show it:

1

A detail of a table in a side view as an adjustable piece of furniture, the height of the table top being adjustable in relation to a table leg via an electric drive motor,

2

the table according to 1 with raised table top,

3

a side view of a complete table with an electric drive motor in each of the left and right table legs,

4

a schematic representation of several tables with the transmission of the occupancy status of each table to a central unit,

figure 5

a perspective view of a controller for controlling an electric drive motor,

6

a cut lengthways through the controller.

The same components are provided with the same reference symbols in the figures.

In the Figures 1 and 2 a table 1 with a table top 3 on a table leg 2 is shown as an example of a piece of furniture. The table leg 2 forms a furniture support section, and the table top 3 forms a furniture adjustment section, with the table top 3 being arranged such that it can be adjusted in height relative to the table leg 2 . The height is adjusted with the aid of an electric drive motor 4 which is arranged on the underside of the table top 3 on a guide part 3a which protrudes into the table leg 2 and is guided in the table leg 2 so as to be displaceable. The drive motor 4 causes a shaft 5 to rotate, which meshes with an associated counter-thread in the table leg, with the shaft 5 being connected in an axially stationary manner to the guide part 3a, as a result of which the desired height adjustment of the table top 3 is effected when the shaft 5 rotates.

On the underside of the table top 3 there is a control device 6, via which the electric drive motor 4 is controlled. The control device 6 includes a controller and a sensor device 7, whose sensor signals are processed in the controller to control signals with which the drive motor 4 is controlled. The electric drive motor 4 can rotate in both directions be controlled in order to cause a corresponding lifting movement of the tabletop 3 up or down.

The sensor device 7 comprises, for example, a gyro sensor for determining the relative inclination of the tabletop 3 with respect to the table leg 2 or an absolute rotation of the tabletop and a gravitational sensor which, for example, outputs an absolute inclination value. The height of the table top 3 can be determined using a distance sensor that measures the distance to the floor, to a reference or to the ceiling; the distance sensor can also be part of the sensor device 7 .

In 3 an overall view of a table 1 is shown, which has two table legs 2 which together support the table top 3 . A guide part 3a protrudes into each table leg 2 on the underside of the table top 3 and carries an electric drive motor 4 via which the respective guide part 3a can be adjusted in height relative to the receiving table leg 2 . The two electric drive motors 4 are both controlled by the control device 6, which includes a sensor device 7 that works without contact. The gesture control via the sensor device 7 takes place as in the example according to FIG Figures 1 and 2 via a manually performed gesture in the detection area according to arrow 8 above the sensor device 7 and the top of the table top 3.

The two electric drive motors 4 can be controlled in a synchronous manner via the common control device 6 . Optionally, independent activation of the two electric drive motors 4 is also possible.

This makes it possible, for example, to set a target inclination of the table top 3, for example a horizontal alignment of the table top despite an uneven floor or a defined desk inclination. If a number of sensors are arranged in the sensor device 7, a number of degrees of freedom of movement of the tabletop 3 can be determined accordingly and set to the desired target values via the various drive motors.

The electric drive motors 4, which are used in the above-described examples in the tables 1, are preferably to be operated with mains voltage of the household power supply electric motors without galvanic isolation between the household power supply and the drive motor. Such motors, which are connected to the regular power grid, have the advantage that a transformer is not required. If necessary, the motors can be operated via corresponding power electronics with a lower voltage than the household voltage. The control devices or controllers can be dimensioned smaller. In addition, despite higher performance, less heat is generated, which significantly increases the availability of the electric drive motors.

The drive motors are, for example, a universal motor, a permanently excited commutator motor or a brushless DC motor.

Various electric drive motors, especially in different pieces of furniture, can possibly be powered by the mains power supply due to their design as mains current motors be synchronized. This has the advantage that the drive motors can also be synchronized over long distances without the need for communication lines.

In 4 an example is shown with a plurality of pieces of furniture 1, which are each designed as a table and have a height-adjustable table top. The sensor device in each table 1 can be used to determine the current occupancy status with the occupancy of a person at each table. For this purpose, the sensor information from the sensor device in each table 1 is evaluated by comparison with a reference movement pattern. The data acquisition via the sensor device in each table 1 takes place over a minimum period of time in order to obtain a movement pattern of the furniture adjustment section formed by the table top, from which the current occupancy status can be inferred.

As soon as a person sits or stands at a table and, in particular, applies a load that is typical for office work to the tabletop, which occurs, for example, when placing your arms on the tabletop and/or when writing, a movement pattern typical of this activity arises, which is detected with the help of the sensor device in the Table 1 is picked up. The recorded movement pattern is compared with a reference movement pattern, and if there is sufficient correspondence between the recorded movement pattern and the reference movement pattern, it can be concluded that the table is occupied by a person. This reference movement pattern, typical of a occupied table, differs from one Movement pattern that occurs, for example, when raising or lowering the table top, when adjusting the table top inclination or in the event of an accidental jolt. This makes it possible to differentiate between different movement patterns and, in particular, to identify the occupancy status of the table. The identification is carried out during a rest phase of the electric drive motors in the tables 1.

In each table 1, an occupancy signal 12 is generated from the comparison of the movement pattern recorded by sensors in the reference movement pattern. For example, the occupancy signal 12 in each table can have the value "0" for an unoccupied table and the value "1" for an occupied table.

The occupancy signals 12 are transmitted to a central office 9 . The transmission takes place either wirelessly or via data or communication lines. The occupancy signals 12 are evaluated in the central office 9, for example to the effect that a comparison is carried out between tables 1 that are actually not occupied and a current need for tables that are not occupied. This makes it possible to fill the unoccupied tables with people occupy, who are currently looking for a free table.

The central office 9 controls an output unit 10 in which, for example, the tables 1 that are not occupied are displayed optically, so that people who are looking for a table that is not occupied can occupy it accordingly. In addition or as an alternative, it is also possible to control one or more technical devices 11 depending on the occupancy status of the tables 1, for example lighting devices or

Air conditioning equipment, e.g. to illuminate the occupied tables accordingly or to heat or cool the working environment of the occupied tables.

FIG. 5 shows a controller 13 for an electric drive motor with a housing 14 for accommodating a circuit board of the controller. The housing 14 of the controller 13 is made in particular from plastic and can be reinforced with glass fibers. For example, PA66 or a polycarbonate can be considered as the plastic material. The material can have a wall thickness of at least 2 mm, for example, so that the housing 14 has a high level of strength and stability. On the inner wall of the housing 14 there can be grooves 17 (FIG. 6) running in the longitudinal direction, into which the circuit board of the controller can be inserted.

An operating unit 15 with operating buttons 16 for switching the electric drive motor on and off is located in the area of a front side of the housing 14 . The operating unit 15 closes the end face of the housing 14 so that the interior of the housing is hermetically sealed from the outside. The Operating unit 15 can also be made of a plastic material. The integration of the operating unit 15 in the housing 14 of the controller results in a compact, space-saving arrangement. In one embodiment of the piece of furniture, for example, the controller 13 is arranged as a height-adjustable table on the underside of the table adjacent to the front edge of the table. Due to the high stability of the housing 14, it is also able to absorb higher forces without the risk of destruction.

Since there is no galvanic isolation between the household power supply and the drive motor or the controller 13, the operating unit 15 with the operating buttons 16 is located at a sufficient distance of, for example, 6 mm from the circuit board inside the housing 14 to ensure the necessary safety. The distance can be bridged, for example, via extensions of the buttons 16 with which switches on the circuit board are actuated. Alternatively, it is also possible to transmit signals to the circuit board without contact, for example by using light sources and phototransistors on the circuit board or the operating unit or by using a radio module for signal transmission.

Claims (12)

1. Method for detecting the state of occupancy of at least one piece of furniture (1) in the form of a table, having a sensor device (7) for detecting a movement of a furniture part (3) of the piece of furniture (1),

   wherein the piece of furniture (1) is detected as occupied by an individual and an occupancy signal (12) is generated if a movement pattern of the furniture part (3) which corresponds to a reference movement pattern for an occupied state is determined via the sensor device (7),

   wherein the furniture part (3) the movement of which is sensed via the sensor device (7) is an adjustable furniture part (3), the adjustable furniture part (3) is adjustable with respect to a furniture support part (2) of the piece of furniture (1) and a relative movement of the adjustable furniture part (3) with respect to the furniture support part (2) is detected by the sensor device (7),

   wherein the piece of furniture (1) has at least one electric drive motor (4) for adjusting the adjustable furniture part (3) with respect to the furniture support part (2),

   wherein the movement pattern of the adjustable furniture part (3) for detecting the occupancy state is determined during a rest phase of the electric drive motor (4), wherein the movement of the adjustable furniture part (3) is monitored continuously and a comparison with the reference movement pattern is carried out as soon as a movement of the adjustable furniture part (3) over a minimum time period is detected with the aid of the sensor device (7).
2. Method according to Claim 1,
   characterized in that
   an absolute movement of the furniture part (3) in space is detected by the sensor device (7).
3. Method according to Claim 1 or 2,
   characterized in that
   the height-adjustable table top forms the adjustable furniture part (3) and at least one table leg forms the furniture support part (2), and the movement pattern of the table top (3) is determined with the aid of the sensor device (7).
4. Method according to one of Claims 1 to 3,
   characterized in that
   a change in inclination of the furniture part (3) is detected via the sensor device (7).
5. Method according to one of Claims 1 to 4,
   characterized in that
   the occupancy signal (12) of the piece of furniture (1) is fed to a central location (9).
6. Method according to one of Claims 1 to 5,
   characterized in that
   depending on the occupancy state of the piece of furniture (1), one or more technical devices (11) of the piece of furniture (1) or in the surroundings of the piece of furniture (1) are activated.
7. Method according to one of Claims 1 to 6,
   characterized in that
   
   the occupancy state of a plurality of pieces of furniture (1) is detected, wherein each piece of furniture (1) is provided with a sensor device (7) for detecting an adjustment movement of the furniture part (3), wherein the occupancy signals (12) from occupied pieces of furniture (1) are fed to the central location (9).
8. Method according to Claim 7,
   characterized in that
   in the central location (9), one or more unoccupied pieces of furniture (1) are allocated to one or more individuals.
9. Method according to one of Claims 1 to 8,
   characterized in that
   the drive motor (4) is designed as an electric motor which can be operated with mains voltage without galvanic isolation between the domestic power supply and the drive motor (4).
10. Method according to one of Claims 1 to 9,
    characterized in that
    at least two electric drive motors (4) for adjusting the adjustable furniture part (3) with respect to the furniture support part (2) are arranged in the piece of furniture (1).
11. Method according to one of Claims 1 to 10,
    characterized in that
    the piece of furniture (1) is provided with a sensor device (7) for detecting the position or a movement of a furniture part (3), and the at least one drive motor (4) can be activated as a function of the sensed position or the movement.
12. Method according to one of Claims 1 to 11,
    characterized in that
    at least two electric drive motors (4) in one or in a plurality of pieces of furniture (1) are synchronized via the power supply.

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