HEIGHT-ADJUSTABLE TABLE

Abstract

The present invention relates to an improved height-adjustable table (1) which can assist and motivate the user to use the height-adjustable table in a manner which increases health, burning of calories and well-being. The table features a system for determination of user presence and measurement of the time of user presence which can be used for alerting the user to change from a sitting to a standing position in front of the table in intervals based on the practical user presence of the table.

Claims

1. A height-adjustable table (1) comprising: a frame, a table top and a linear electric actuator system for providing a vertical displacement of the table top relative to the frame, where the linear electric actuator system comprises: at least one linear actuator (3), a control (9), a system for determining the actual height-adjustment level of the table providing information to the control (9), an operating unit (6) with activation keys for user activated height-adjustment of the table, where the operating unit (6) is connected to the control and configured to transmit requests corresponding to the activation of the activation keys; a system for determination of user presence comprising a microcontroller and at least one sensor for picking up signals originating from mechanical vibrations generated by the user and conveyed through the components of the height-adjustable table, the at least one sensor being arranged in its position on one of the components of the height-adjustable table, and where the microcontroller is adapted to sample and record the signals obtained by the at least one sensor into a set of data, further filtering the set of data in order to collect signals originating from user presence, and suppressing noise signals originating from sources not relating to user presence, integrating the filtered signal over a time interval and determining, by comparing to threshold values or data patterns, the state of user presence, being determined to be one of 1) present at the table or 2) not present at the table and where the system for user presence further includes an interface for indicating or communicating said state to the control.

2. A height-adjustable table according to claim 1, where the sensor for picking up signals originating from mechanical vibrations is either a vibration sensor; an acoustic sensor; or an accelerometer.

3. A height-adjustable table according to claim 2, where the sensor is arranged in its position on one of the components of the height-adjustable table by means of a non-flexible means which conveys the vibrations from the table to the sensor.

4. A height-adjustable table according to claim 2, where the sensor is arranged in a cavity formed in the table top, said cavity being adapted for receiving and retaining the sensor in its position, and where the walls of the cavity are adapted for conveying the mechanical noise to the sensor.

5. A height-adjustable table according to claim 2, where the acoustic sensor is a microphone capsule.

6. A height-adjustable table according to claim 5, where the system comprises two microphone capsules where the first microphone capsule is arranged connected to a component of the table by means of a non-flexible fixing means, which is non-dampening of mechanical noise, such as a hard plastic or metal bushing, and where the second microphone capsule is arranged with a mechanical noise dampening means such as a rubber or silicone bushing and where the microcontroller samples and records the signals in the time domain and determines a state of user presence, and where the signal from the microphone capsule, arranged with a mechanical noise dampening means, is used for determining the background noise, in order to calibrate the state of user presence accordingly while compensating for the background noise.

7. A height-adjustable table according to claim 2, where the sensor is an accelerometer and where the signals from the sensor, which represent the individual axis, are sampled by the microcontroller, and the difference in amplitude from the previously sampled value is calculated, and the difference in the measured values from the individual axis is combined into one resulting value, corresponding to the incremental measured value of the mechanical vibration induced by the user for that specific sample, and that the measured value of the resulting values of samples is integrated over time, enhancing the integrity of the value, and that the integrated value is compared with a threshold value for determining the state of user presence, the state of user presence being determined to be one of 1) present at the table or 2) not present at the table, and where the system for user presence further includes an interface for indicating or communicating said state of user presence to the control.

8. A height-adjustable table according to claim 1, where the sensor is arranged in connection with or in the control, or with the control panel, or in a separate housing, and connected to the control or control panel by a cable, or where the sensor is arranged in a dongle which can be plugged into a port in the control or control panel.

9. A height-adjustable table according to claim 1, where the sensor is arranged outside the control or the control panel and is equipped with means for fixation of the sensor itself in mechanical connection with a component of the table such as the table top, ensuring that the sensor picks up the vibrations generated by the user being present at the table and conveyed through the component of the table.

10. A height-adjustable table according to claim 1, where the system has means for registering the lapsed time where the state of user presence has confirmed the user to be present at the table, and means for alerting the user to change between a sitting and standing position based on predetermined sit/stand intervals.

Description

[0028] An embodiment of the invention will be described more fully below with reference to the accompanying drawing, in which:

[0029] FIG. 1 shows a perspective view of a height-adjustable table,

[0030] FIG. 2 illustrates a height-adjustable table in a sitting position,

[0031] FIG. 3 illustrates the height-adjustable table in a standing position,

[0032] FIG. 4 is a schematic diagram of the height-adjustable table,

[0033] FIG. 5 is a schematic diagram of the height-adjustable table having a user presence determination system with a microphone,

[0034] FIG. 6 shows the same schematic diagram of the height-adjustable table as shown in FIG. 5 but featuring an accelerometer,

[0035] FIG. 7 shows the height-adjustable table where the table top is shown transparent,

[0036] FIG. 8 shows a recording of a microphone signal,

[0037] FIG. 9 shows a recording of an accelerometer signal,

[0038] FIG. 10 shows the combined value of the accelerometer signals,

[0039] FIG. 11 shows a flow chart diagram for measurement and evaluation of sensor values, and

[0040] FIG. 12 shows the state machines algorithm for changing states.

[0041] FIG. 1 shows a perspective view of a height-adjustable table 1 comprising a table top 2. At each side of the height-adjustable table 1 a linear actuator in the form of a lifting column 3 is mounted in a carrying frame (not shown) onto which the table top 2 is mounted. The other end of each lifting column 3 comprises a foot 4 on which the height adjustable-table 1 stands. The lifting columns comprise a drive unit (not shown) and two or three mutually telescopically arranged profiles. One profile 5 is stationary fixed to the foot 4 and one profile (not referenced) is stationary fixed to the motor housing. Each lifting column 3 is driven by means of an electric motor, which drives a spindle through a gear. The spindle is furnished with a spindle nut secured to the telescopically movable profile(s). The height-adjustment of the table top is thus performed by the lifting columns 3. The adjustment is achieved by activating the operating panel 6.

[0042] FIGS. 2 and 3 illustrate a side view of the height-adjustable table 1 in a sitting position 7 and a standing position 8, respectively. Since the length of the lifting columns 3 can be adjusted, the sitting position 7 and standing position 8 can be set to accommodate the physical characteristics and personal preferences of each individual user of the height-adjustable table 1.

[0043] FIG. 4 depicts a schematic view of the height-adjustable table 1 comprising a linear actuator 3, a control 9, a system 10 for determining the actual height adjustment level of the height-adjustable table 1, and an operating panel 6.

[0044] The system 10 for determining the actual height adjustment level could be determined by potentiometers or Hall sensors built into the linear actuators 3 or by other detection means such as an optical sensor. The system 10 for determining the actual height adjustment level provides input information about the actual height adjustment level to the control 9.

[0045] The operating panel 6 is connected to the control 9 for user activation requesting an adjustment of the height level of the height-adjustable table 1 by supplying the at least one linear actuator 3 from an appropriate source of electrical energy (not shown).

[0046] The control 9 comprises a memory 11 for storing at least one height adjustment setting 7,8 referring to a sitting position 7 or a standing position 8.

[0047] FIG. 5 shows a system for user presence determination including a user presence controller 14, which has an interface to the control 9. Here, the interface is pictured forming a first communication interface 12 and a second communication interface 13, which serve for data communication between the control 9 and the user presence controller 14. It is foreseen that the user presence controller 14 in an embodiment can be integrated in the control 9 utilizing the same physical microcontroller as utilized by the control 9. However, FIG. 5 shows that the system for user presence determination can be an add-on feature, which can be carried out as an extension of the control 9 connectable to the control constructed as a dongle with or without a cabled connection or as a piggy back board connectable directly on the printed circuit board for the control and thus being encapsulated in the same housing as the control 9. As it appears from FIG. 5, the user presence determination system includes a sensor in the form of a microphone capsule 15, which submits an analog audio signal that reflects the vibrations of the height-adjustable table, when the microphone capsule is secured to one of the components of the table. It is appreciated that the microphone capsule is arranged in a cavity formed in the table top in such a manner that the surrounding sounds do not have direct access to the microphone capsule. This has the advantage that only the vibrations in the table, originating from user presence, are picked up by the microphone capsule, which will also make the user presence determination system more immune to surrounding sounds in the form of talk, which will be dampened by the mass of the table top. The analog signal from the microphone capsule is sampled by an ADC (Analog-digital converter) which transforms the analog signals into the digital domain and forwards the signals to the user presence controller for processing. The sampling rate of the ADC can be low since only low frequent signals are of interest. Any signals in the range of 1000 Hz or more will in normal applications, be possible to cut off. However, specific applications as e.g. recognizing if a ventilator fan is spinning could prescribe that a higher sampling rate is needed.

[0048] FIG. 6 shows the same basic principle as shown in FIG. 5, but the microphone capsule 15 has been exchanged to an integrated circuit in the form of an accelerometer, the output of which changes in acceleration in all three geometrical directions (x, y, z plane) directly as digital values. Thus, an ADC is not needed since the accelerometer interfaces the microcontroller for the user presence determination system directly. As with the microphone capsule 15, the accelerometer 16 should be arranged in such a way in connection with the height-adjustable table on one of its components that it picks up vibration signals originating from user presence.

[0049] FIG. 7 shows the height-adjustable table where the table top is shown transparent. The user presence determination system is arranged in connection with the control 9 in the same housing or in the same housing as the operating panel 6, but could also be arranged in its own housing (not shown) and secured to one of the components of the height-adjustable table, preferably the table top. As a courtesy, it is understood that the sensor itself can be arranged in close proximity to the user presence determination system or be remotely arranged but interfacing the user presence determination system via a cabled connection (not shown).

[0050] FIG. 8 shows a recording of a microphone signal. The microphone is arranged in a fixed connection with the table top. As it appears, the microphone capsule picks up very nicely the vibrations originating from user presence. As it can be seen, normal office trivialities as handling paper, typing on a keyboard or using a computer mouse generates sufficient noise or vibration signals to clearly distinguish from periods where there is no activity. A period without activity can be seen between the events of handling papers and typing on a keyboard.

[0051] For the sake of completeness, a similar signal is shown in FIG. 9, but with the difference that the signal origins from an accelerometer 16. The three signals from the accelerometer have been recorded for each axis (x, y, z plane). In a further step, the difference in value to the previous signal for that specific axis has been calculated. In a further step, for which the result is shown in FIG. 10, the three signals corresponding to each of the incremental movements since the last sample are combined into one value which reflects the magnitude of the vibration. The direction is not particularly interesting for this application. Thus, the magnitude of the signal is shown in FIG. 10. As with the microphone capsule, using an accelerometer also makes it possible to clearly distinguish between noise and vibrations originating from a user being present and a silent level.

[0052] A flow chart diagram for measurement and evaluation of sensor values is shown in FIG. 11. As a first step, data is sampled by the user determination controller system and stored. Further, the values are evaluated in order to filter out values that appear as spikes or out of boundaries. In a further step, the signal is evaluated and filtered with regard to frequency content in a manner which filters out frequency content below a frequency defined as filter 1 and above a frequency defined as filter 2. The filter values can easily be changed by modifying the values in the software. The filtered signal is in a further step integrated in order to obtain a value, which has integrity over time. A comparator compares the signal with threshold values, which are also defined in the software and are changeable. Depending on the state, presence or non-presence, a threshold value Threshold 1 or Threshold 2 is used to determine if a shift in state should be made from presence to non-presence or vice versa. The state machine is shown in FIG. 12, but is further configured with a timer value in the form of delta time T1 and delta time T2 which serves to allow periods of time of inactivity within a period which can still be considered an active state of presence. The same goes for short intervals of activity within a period of time where the state can still be considered an inactive state of presence. The delta time T1 and T2 can be configured by changing the values in the software.

[0053] It is also within the scope of the invention when some of the functionality such as e.g. the comparator, the threshold settings, the delays of state shifting are implemented outside the user presence determination system. This could be implemented in the software being run on the microcontroller for the control or in applications on e.g. a personal computer or smart mobile device which connects to the control 9 via a wired or wireless connection. However, a full system for alerting the user of a height-adjustable table to change between a sitting and a standing position or vice versa could be implemented sharing the same microcontroller, which could be the microcontroller which features the user presence determination system. With the information on acceleration and deceleration changes in the vertical direction originating from height-adjustments of the actuator system and sensed by the accelerometer, the system will be able to determine if the table top has been adjusted to a low or to a high position. Such input can be used for specifying if the next alert will be prompting the user to change from a sitting position to a standing position or vice versa. However, if specific measurements contained in the actuator system corresponding to the actual height-adjustment setting, are needed for specifying if the table top is adjusted to a position, which corresponds to a sitting or standing position, it will be obtainable via an interface for the control 9, and be specified by means of e.g. an incremental position determination system implemented in the actuator system itself.